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Hate (({allege of Agriculture 

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Cornell University Library 
TX 543.W7 1916 

The microscopy of vegetable foods, with s 

3 1924 003 711 151 


Cornell University 

The original of this book is in 
the Cornell University Library. 

There are no known copyright restrictions in 
the United States on the use of the text. 92400371 1 1 51 




The Microscopy of Vegetable Poods. 

With Special Reference to the Detection of Adul- 
teration and the Diagnosis of Mixtures. By 
Andrew L. AYinton, Ph.D., with the Collabora- 
tion of Dr. Josef Moeller, Professor of 
Pharmacognosy, and Head of the Pharmacognos- 
tical Institute of the University of Vienna, and 
Kate Barber Winton, Ph.D. xiv+701 pages, 
6J by 10, 635 figures. Cloth, $6.50 net. 

The Microscopy of Technical Products, 

By Dr. T. F. Hanatjsek. Revised by the author 
and translated by Andrew L. Winton, Ph.D., 
with the collaboration of Kate Barber Winton, 
Ph.D. xii+471 pages , 6J by 10, 276 figures. 
Cloth, S5.00 net. 

Food Inspection and Analysis. 

By Albert E. Leach, S.B.,Late Chief of the U. S. 
Food and Drug Laboratory at Denver. Revised 
and enlarged by Andrew L. Winton, Ph.D. xxi 
+1001 pages, 6} by 10, 120 figures, 40 full-page 
half-tone plates. Cloth, $6.50 net. 








Formerly Chief of the U. S. Food and Drug Laboratory at Chicago; formerly in Charge of the 
Analytical Laboratory of the Connecticut Agricultural Experiment Station, etc, 



Aulic Counselor, Professor of Pharmacognosy, and Head of the Pharmacognostical Institute 
of the University of Vienna 


Formerly Micro-Analyst U. S. Bureau of Chemistry 





London : CHAPMAN & HALL, Limited 

Copyright, 1906, 1916 



First Edition Entered at Stationers' Hall 

11-10 PRESS OP 





In the preface to the first edition attention was directed to the develop- 
ment of food microscopy on the continent, to its practical importance, and 
to the lack of a comprehensive work on the subject in the English language. 
Since that time microscopic methods have come into more general use 
throughout the United States in the examination of human and cattle 
foods, and as a consequence certain fraudulent practices have been sup- 
pressed or much restricted. Both the author and his helpmate have been 
identified with this movement as State and Federal officials and as inde- 
pendent investigators and have thus collected data which are incorporated 
in the present edition. 

Among the features of the edition are additions to the sections on wheat 
and flour, a complete revision of such parts of the chapter on oil seeds as 
treat on mustards, rapes, cruciferous weed seeds, and linseed, a description 
of the histology of alfalfa with distinctions from red and alsike clover, a 
revision of the sections on pomes and drupes with practical hints on the 
examination of almond pastes, jams, preserves and other fruit products, 
and rewritten descriptions of the cucurbitaceous fruits used as foods and 

Of the 68 cuts which have been added over half are here published for 
the first time and the remainder, with one exception, have appeared only 
in journal articles. Twenty-two cuts have been dropped. 

The idea that a scientific grounding is essential for practical work has 
never been out of mind. Experience has shown that the systematic study 
of each product from the morphological and physiological standpoint 
develops not only the keenest observation but also the faculty of naming 
a product from a single fragment just as the paleontologist forms his picture 
of an entire animal from a single bone. 

The application of the microscopy of foods is by no means limited to 
the detection of adulteration and the identification of unknown materials. 
The miller, the brewer, the oil presser, the feed manufacturer, the canner, 
and the coffee and spice grinder should be conversant with the structure 


as well as the chemical composition of their raw materials, and the student 
in the school of technology should follow both lines of study in order that 
he may be prepared to attack the complicated problems of the industries. 

As was stated in the preface to the first edition, the work is closely 
affiliated with the second edition of Moeller's " Mikroskopie der Nahrungs- 
und Genussmittel," which was published in 1905 with the collaboration of 
the author. The descriptions of most of the leaves, flowers, barks, roots, 
and edible fungi, upward of 125 pages, are translations of Professor Moel- 
ler's text, and no less than 332 cuts are also his. The author again acknowl- 
edges with the deepest gratitude this generous cooperation of his honored 
teacher and friend. 

Valuable cuts have been borrowed from the works of Berg, Collin and 
Perrot, Frank, Gilg, Hager, Halstrom, T. F. Hanausek, Hartig, Hassall, 
Kny, Leach, Luerssen, Malfatti, A. Meyer, Mez, R. Miiller, Nees, Nobbe, 
Planchon and Collin, Sachs, Schimper, Schumann, Tschirch, Tschirch 
and Oesterle, Tulasne, Vogl, and Warburg. Grateful acknowledgment 
is due these authors also their publishers as follows: Julius Springer, 
Berlin (publisher of Moeller's Mikroskopie); The Clarendon Press, 
Oxford; Wm. Engelmann, Leipsig; Ferdinand Enke, Stuttgart; Gustav 
Fischer, Jena; Carl Gerold's Sohn, Vienna; H. Haessell, Leipsig; Alfred 
Holder, Vienna; A. Joanin & Cie., Paris; Longmans, Green, & Co., 
London; Paul Parey, Berlin; Chr. Herm. Tauchnitz, Leipsig; Urban 
& Schwarzenberg, Berlin and Vienna; J. J. Weber, Leipsig; Weidmann- 
sche Buchhandlung, Berlin. Permission to reproduce Fig. 16 was kindly 
granted by Mr. E. Goodwin Clayton, F.I.C., F.C.S., consulting chemist, 
32 Holborn Viaduct, London, England. Numerous cuts, made from the 
author's drawings for publications of the Connecticut Agricultural Experi- 
ment Station, are reproduced with the kind permission of that institution. 
The larger part of the collaborators' and the author's drawings were repro- 
duced on wood by F. X. Matolony of Vienna. 

In the preparation of the text the works of the leading authors have 
been consulted, and credit has frequently been given for important dis- 
coveries, although so far as possible the descriptions have been based on 
original observations. 

Wilton, Conn., 

November 1, 1913. 











Mechanical Preparation 12 

Treatment with Reagents 15 


Tissues ■ 20 

Ceia-contents 23 


The Leaf 28 

The Flower 3° 

The Fruit 33 

Pericarp 33 

Seed 35 . 

The Stem 38 

Bark 4° 

Wood 41 

The Root. 44 



Flour and Meal 47 

Impurities and Adulterants 47 

Methods of Examination 50 




Bread 55 

Cattle Foods 56 

Methods of Examination 58 

CEREALS (Graminece) 60 

Microscopic Characters 61 

Analytical Keys 62 

Wheat (Triticum) 65 

Spelt (Triticum sativum var. Spelta) 73 

Emmer (Triticum sativum var. dicoccum) 75 

One-grained Wheat (Triticum monococcum) 76 

Rye (Secale cereale) 77 

Barley (Hordeum sativum) 80 

Maize (Zea Mays) •. 86 

Broom Corn (Andropogon Sorghum var. lechnicus) 97 

Sugar Sorghum (Andropogon Sorghum var. saccharatus) 103 

Kaffir Corn (Andropogon Sorghum) 104 

Durrha (Andropogon Sorghum var. durra) 104 

Rice (Oryza saliva) 105 

Oats (Avena sativa) m 

Common Millet (Panicum miliaceum) 116 

German Millet (Setaria Italica = S. panis) 118 

Green Foxtail (Setaria viridis = Chcetochloa viridis) 118 

Yellow Foxtail (Setaria glauca = Chcetochloa glauca) 124 

Darnel (Lolium lemulenlum) 125 

Chess (Bromus secalinus) 1 30 

Buckwheats (Polygonaceoe) 132 

Common Buckwheat (Fagopyrum esculentum) 132 

Tartary Buckwheat (Fagopyrum Tartaricum) 138 

Black Bindweed (Polygonum Convolvulus) 138 

Other Polygonaceous Seeds , 144 


Screenings 145 

European 145 

American 146 

Analyses 147 

Methods of Examination 148 

CaryophyllacEous Seeds (Caryophyllacece) 148 

Cockle (Agro stemma Githago) 14S 

Cow Herb (Vaccaria parvifiora —Saponaria Vaccaria) 151 

Soapwort (Saponaria officinalis) jj, 

Spurrey (Spergula arvensis) u 2 

Ranunculaceous Seeds (Ranunculaceoi) " 152 

Buttercup Fruit (Ranunculus arvensis) 153 

Adonis Fruit (Adonis aestivalis, A. Flammed) ,c. 

Larkspur Seed (Delphinium Consolida) i 55 

Louse Seed (Delphinium Staphysagria) t er 

Black Caraway (Nigella arvensis) I5 5 

Miscellaneous Weed Seeds IS 6 

Cow Wheat (Melampyrum arvense) 1 c6 

Bindweed (Convolvulus arvensis) 1 57 



Wild Carrot {Daufus Caroia) 158 

Hollow Seed (Bijora radians) 159 

Cornflower (Centaurea Cyanus) 160 

Cleavers {Galium) 161 

Plantain {Plantago major, P. lanceolata) 163 


Ergot {Claviceps purpurea) .■ 164 

Smuts {Ustilago, Tilletia, etc.) 166 



Oil-seed Products 169 

Methods of Examination 1 70 

Cruciferous SEEds (Cfuci)erce) 173 

Microscopic Characters 173 

Analytical Key 175 

White Mustard (Brassica alba) 177 

Black Mustard {Brassica nigra) 180 

Brown Mustard {Brassica Besseriana) 183 

Charlock {Brassica arvensis) 184 

Common Rape {Brassica Napus) 186 

German Rape {Brassica Rapa) 187 

Indian Colza {Brassica campestris var. Sarson) 188 

Brown Indian Rape {Brassica Napus var. dichotoma) 18S 

Indian Mustard {Brassica juncea) 180 

Palai Rape {Brassica rugosa) 1 89 

Dissected Mustard {Brassica dissecta) 1 89 

Eruca {Eruca saliva) 190 

False Flax {Camelina saliva) 190 

Hedge Mustard {Sisymbrium officinale, S. Sophia, etc.) 192 

Shepherd's Purse {Capsella Bursa-Pastoris) 192 

Wild Peppergrass {Lepidium Virginicum, L. campeslre, L. sativum) 193 

Field Pennycress {Thlaspi arvense) igj 

Treacle Mustard {Erysimum orientate) 194 

Wild Radish {Raphanus Raphanistrum) 194 

Winter Cress {Barbarea vulgaris) 194 

Composite Oil Fruits {Composites) 195 

Sunflower {Helianthus annuus) 195 

Madia Seed {Madia saliva) 198 

Niger Seed {Guizotia A byssinica = G. oleijera) 200 

Miscellaneous Oil Seeds 202 

Linseed {Linum usitatissimum) 2G2 

Cottonseed {Gossypium herbaceum) 207 

Kapok Seed {Ceibo pentandra —Eriodendron anfraciuosum) 213 



Hemp Seed (Cannabis sativa) ? 214 

Sesame Seed (Sesamum Indicum) 219 

Castor Bean (Ricinus communis) 222 

Candlenut (Aleurites triloba =A. Moluccana) 224 

Poppy Seed (Papaver somniferum) 225 

Olive (Oka Europea) 228 



LEGUMES (Leguminosm) 233 

Microscopic Characters 233 

Analytical Key 235 

Common Bean (Phaseolus vulgaris) 238 

Spanish Bean (Phaseolus multiflorus) 240 

Adzuki Bean (Phaseolus Mungo, var. glaber) , . . . . 241 

Lima Bean (Phaseolus lunatus) 241 

Pea (Pisum arvense, P. sativum) 242 

Lentil (Lens esculenta =Ervum Lens) 245 

China Bean (Vigna Catjang = V. Sinensis = Dolichos Sinensis) 247 

Soy Bean (Glycine hispida =Soja hispida) 248 

Egyptian Bean (Dolichos Lablab = Lablab vulgaris) 249 

Horse Bean (Faba vulgaris = Vicia Faba) 250 

Spring Vetch (Vicia saliva) 251 

Winter Vetch (Vicia villosa) 252 

Hairy Vetch (Vicia hirsuta) : 252 

Yellow Lupine (Lupinus luteus) 253 

White Lupine (Lupinus albus) 255 

Blue Lupine (Lupinus anguslijolius) 255 

Chick Pea (Cicer arietinum) 256 

Soudan Coffee (Parkia Africana, P. Roxburgii) 257 

Jack Bean (Canavalia ensiformis, C. oblusijolia) 258 

Fenugreek (Trigonella Faenum-Grcecum) 259 

Coffee Cassia (Cassia occidentalis) 262 

Astragalus (Astragalus bceticus) 264 

Alfalfa (Medica sativa) 265 

Peanut (Arachis hypogtza) 269 

Tonka Bean (Coumarouna odorata =Dipteryx odorata, etc.) 275 

Carob Bean (Ceratonia Siliqua) m 2-7 





NUTS 281 

Palm Fruits {Palmes) 281 

Cocoanut {Cocos nucifera) 281 

Palm-nut {Eltzis Guineensis) 290 

Wax-palm {Corypha cerijera = Copernica cerifera) 292 

Ivory-nut {Phytelephas macrocarpa, etc.) 293 

Polynesian Ivory-nut {Coelococcus) 295 

Walnuts (JuglandaceiB) 295 

European Walnut (Juglans regia) 295 

Black Walnut {Juglans nigra) 298 

Butternut {Juglans cinerea) 298 

Pecan Nut {Carya olivcejormis) 298 

Hickory-nut {Carya alba) .' 299 

Cup Nuts {Cupulijercs) 299 

Chestnut {Casianea sativa, etc.) 299 

Acorn {Quercus) ; 302 

Beech-nut {Fagus sylvatica, F. ferruginea) 307 

Hazelnut {Corylus) 309 

Miscellaneous Nuts 312 

Brazil-nut {Bertholletia nobilis) 312 

Pistachio-nut {Pistacia vera) 315 

Pine-nut {Pinus Pinea, P. Cembra) 316 



FRUIT 3 i 7 

Fruit Products 317 

Adulterants 317 

Methods of Examination 318 

Rosaceous Fruits {Rosacea) 32 1 

Apple {Pyrus Malus) 321 

Pear {Pyrus communis) 326 

Quince {Cydonia vulgaris = Pyrus Cydonia) 330 

Almond {Prunus amygdalus) 332 

Peach {Prunus Persica) 337 

Apricot {Prunus Armeniaca) 339 

Plum {Prunus domestica, P. triflora) 340 

Cherry {Prunus avium, P. cerasus) 341 

Rose Fruit, {Rosa canina) 342 

Strawberry {Fragaria) 343 



Red Raspberry (Rubus Idceus, etc.) 349 

Black Raspberry (Rubus occidentalis) • 354 

Blackberry (Rubus frulicosus, etc.) 354 

SaxiFragaceous Fruits (Saxifragacea) 357 

Red Currant (Ribes rubrum) 357 

Black Currant (Ribes nigrum) 3 62 

Gooseberry (Ribes Grossularia, etc.) 3 6 3 

Ericaceous Fruits (Ericaceae) 3°° 

Cranberry (Vaccinium macrocarpon, etc.) 3"° 

Blueberry (Vaccinium Myrlillus, etc.) 37° 

Huckleberry (Gaylussacia resinosa) 373 

Citrus Fruits (Rutacece) 376 

Orange (Citrus Auraniium) 37° 

Lemon (Citrus medica, var. Limon) 3^! 

Citron (Citrus medica, var. genuina) 3^1 

Miscellaneous Fruits 382 

Grape (Vilis vinijera) 3^ 2 

Fig (Ficus Carica) 3^6 

Date (Phoenix dactylijera) 39° 

Banana (Musa sapientum) 393 

Pineapple (Ananassa saliva) 395 




Cucurbit Fruits (Cucurbitacece) 397 

Pumpkin (Cucui bita Pepo) 398 

Squash (Cucurbita maxima) 402 

Cucumber (Cucumis sativus) 403 

Muskmelon (Cucumis Melo) 405 

Watermelon (Citrullus vulgaris) 406 

Solanaceous Fruits (Solanacea) 410 

Tomato (Solatium Lycopersicum=Lycopersiciim esculentum) 410 

Tubers and Roots 414 

Potatp (Solanum tuberosum) 414 

Japanese Potato (Stachys Sieboldii) 415 

Jerusalem Artichoke (Helianthus tuber osus) 416 

Beet (Beta vulgaris) 4^ 

Carrot (Daucus Carota) 4!8 

Turnip (Brassica Rapa) 419 

Fungi 419 

Truffles (Tuber) 420 

Morels (Morchella, Gymitra, Hehella) 422 

Mushrooms (Psalliota, Boletus) 423 





Coffee (Coffea Arabica) 427 

Liberian Coffee {Coffea Liberica) 438 

Chicory (Cichorium Iniybus) 438 

Dandelion (Leontodon Taraxacum) 440 

Cocoa Bean (Theobroma Cacao) 442 

Guarana (Paullinia sorbilis) ..." 45 1 

Kola Nut (Cola acuminata) 452 

Tea (Camellia Thea) , . . . . 452 

Gromwell Leaves (Lithospermum officinale) 458 

Willow Herb Leaves (Epilobium angustijolium = Chamaenerium angusti- 

folium) 459 

Willow Leaves (Salix) 461 

Ash Leaves (Fraxinus sp.) ,. . 462 

Rowan Leaves (Sorbus Aucuparia =Pyrus Aucuparia) 463 

Mulberry Leaves (Morus alba, M. nigra) : 464 

Coffee Leaves (Coffea Arabica) 466 

Camellia Leaves (Camellia Japonica) 467 

Cherry Leaves (Prunus avium) 468 

Sloe Leaves (Prunus spinosa) 469 

Rose Leaves (Rosa canina, etc.) 470 

Strawberry Leaves (Fragaria vesca) ^-ji 

Meadowsweet Leaves (Spirtza Ulmaria) 473 

Wistaria Leaves (Wistaria Sinensis =Kraunhia floribunda) 475 

Hydrangea Leaves (Hydrangea Hortensia) 476 

Maple Leaves (Acer Negundo =Negundo fraxinifohum) 477 

Oak Leaves (Quercus pedunculata, Q. sessiliflora) 477 

Akebia Leaves (Akebia quinata) 478 

Blueberry Leaves (Vaccinium Myrtillus) 480 

Caucasian Tea (Vaccinium Arctostaphylos) 481 

Other Tea Substitutes 483 

Mate (Ilex Paraguariensis) 483 

Coca (Erythroxylon Coca) 485 

Tobacco (Nicoiiana Tabacum, N. rustica) 486 






Impurities 493 

Adulterants 494 

Methods of Examination 496 

Analytical Key 49^ 

Condimental Cattle and Poultry Foods 499 

Methods of Examination 500 

PipEraceous Fruits (Pipcracece) 502 

Pepper (Piper nigrum) 502 

Long Pepper (Piper cfpZcinarum, P. longum) . . . .- 511 

Cubebs (/ iper Cubeba) 513 

SolanacEods Fruits (Solanacece) 515 

Paprika (Capsicum) 515 

Cayenne Pepper (Capsicum fastigiatum, etc.) 523 

Myrtaceous Fruits (Myrtacece) 526 

Allspice (Pimenta officinalis, etc.) 526 

Nutmegs and Mace (Myristicacece) , 531 

True Kutmeg and Mace (Myristica jragrans) 531 

Macassar Nutmeg and Mace (Myristica argentea) , 540 

Bombay Mace (Myristica Malabarica) 540 

Cardamoms (Zingiberacece) 542 

Malabar Cardamom (Elettaria Cardamomum, Amomum Cardamomum, 

etc.) 542 

Ceylon Cardamom (Elettaria Cardamomum) 547 

Umbelliferous Fruits (Umbelliferce) 549 

Comparative Histology of Umbelliferous Fruits 550 

Analytical Key 55 1 

Fennel (Fceniculum capillaceum) cc 2 

Caraway (Carum Carvi) 555 

Anise (Pimpinella Anisum) 1-58 

Cumin (Cuminum Cyminum) 560 

Coriander (Coriandrum sativum) cg 2 

Dill (Anetkum graveolens) ,-64. 

Celery Seed (Apium graveolens) ,-g ^ 

Miscellaneous Fruits and Seeds 5 66 

Star-anise (Illicium verum) -gg 

Shikimi (Illicium religiosum) ,-, 

Vanilla (Vanilla planijolia) ._, 

Vanillon (Vanilla pompona) _-o 

Bayberry (Laurus nobilis) __ 

Juniper Berry (Juniperus communis) -o 2 

Barks - • '.'.'.'.'.'. '.'.'.'.'.'.'. 585 

Cassia (Cinnamomum) 0, 

Cassia Buds (Cinnamomum Cassia) 

Ceylon Cinnamon (Cinnamomum Ccylonicum) 



Clove Bark (Dicypellium caryophyllatum) 594 

£anella Bark (Canella alba) 597 

Rhizomes 599 

Ginger (Zingiber officinale, etc.) 599 

Turmeric (Curcuma longa) 602 

Zedoary (Curcuma Zedoaria) 605 

Galangal (Alpinia officinarum, A. calcarata) 606 

Sweet Flag (Acorus Calamus) 608 

Leaves 610 

Sage (Salvia officinalis) 610 

Marjoram (Origanum Majorana) 612 

Savory (Satureja hortensis) 613 

Thyme (Thymus vulgaris) 615 

Hyssop (Hyssopus officinalis) 615 

Bay-leaf (Laurus nobilis) 616 

Tarragon (Artemisia Dracunculus) 617 

Wormwood (Artemisia vulgaris) 619 

Sorrel (Rumex scutatus) 621 

Flowers 622 

Saffron (Crocus sativus) 623 

Marigold Flowers (Calendula officinalis) 627 

Safflower (Carthamus tinctorius) 629 

Cape Saffron (Lyperia crocea) 631 

South African Saffron (Tritonia aurea = Crocosma aurea = Babiana aurea). 632 

Maize Silk (Zea Mays) j. 632 

Cloves (Eugenia caryophyllata = J 'ambosa Caryophyllus = Caryophyllus 

aromaticus) 632 

Clove Stems 636 

Clove Fruit 637 

Capers (Capparis spinosa) 639. 




Analytical Key 649 

Maize Starch (Zea Mays) 651 

Rice Starch (Oryza sativa) 652 

Wheat Starch (Triticum sativum) 653 

Buckwheat Starch (Fagopyrum esculentum) 654 

Leguminous Starches (Leguminosce) 65s 

Chestnut Starch (Castanea vesca) 656 

Horse-chestnut Starch (JEsculus Hippocastanum) 657 

Bean-tree Starch (Castanospermuni Auslrale) 658 

Banana Starch (Musa) 658 



Bread-fruit Starch (Artocarpus incisa) 6 59 

Potato Starch {Solarium tuberosum) 659 

Maranta Starch or West India Arrowroot {Maranta arundinacea) 660 

Curcuma Starch or East India Arrowroot {Curcuma) 662 

Canna Starch or Queensland Arrowroot {Canna) 662 

Yam Starch or Guiana Arrowroot (Dioscorea) 663 

Cassava Starch {Manihot utilissima, M. aipi) 664 

Sweet-potato Starch or Brazilian Arrowroot {Batatas cdulis = 1 pomcea 

Batatas) 665 

Arum Starch or Portland Arrowroot {Arum) 666 

Tacca Starch or Tahiti Arrowroot {Tacca pinnatifida) 667 

Sago {Meiroxylon, Sagus, etc.) 667 

Miscellaneous Starches 669 



INDEX 685 





The Microscopy of Vegetable Foods is an applied analytical 
science having for its purpose the identification of food products of vege- 
table origin by the microscopic structure and microchemical reactions 
of their tissues and cell-contents. 

It is a branch of Analytical Vegetable Histology, other important 
branches being the Microscopy of Drugs, or Microscopic Pharmacognosy, 
and the Microscopy of Fibers. 

Preliminary Study. As the microscopy of foods, like the allied branches 
of analytical histology, is a department of applied botany, it cannot be 
properly taken up until after a course of instruction in the parent science, 
especially that part relating to the histology or microscopic anatomy of 
phanerogamic plants. To omit this is as irrational as to undertake the 
study of analytical chemistry without previous knowledge of general 

This training in botany need not, however, be more than is given in a 
good high-school course with practical histological work, although a sup- 
plementary course in the histology of phanerogams is highly desirable. 

The student should begin his work in food microscopy with a sys- 
tematic study of the most important seeds, fruits, leaves, flowers, roots, 
and barks used as foods or food adulterants. This work should include: 
(i) the macroscopic anatomy; (2) the histology as studied in transverse 
(less often longitudinal or tangential) sections ; (3) the histology as studied 


in surface preparations of the successive layers obtained by scraping or 
stripping; and (4) the microscopic characters of the powdered, pulped, or 
macerated material. Macroscopic preparations show the general nature 
and relative size of the parts; cross-sections, the number of layers, order 
of arrangement, and certain details of structure; surface mounts, the 
details of cell structure most useful in practical work; and mounts of 
the powdered material, much that is learned from surface mounts and in 
addition the characters of the isolated cell-elements and cell-contents. 
The student who has not the time, apparatus, or technique for cutting 
careful sections can use permanent mounts of a collection, or can even 
depend on illustrations of such sections, but he should prepare his own 
mounts for the study of each material in surface view or powder form. 

After this general work, which is analogous to the study of the reac- 
tions of the several bases and acids in his course in analytical chemistry, 
the student is prepared to undertake the diagnosis of mixtures. In this 
work he will find that of some materials, such, for example, as ground 
coffee, he can pick out fragments large enough for cutting sections, or 
preparing surface mounts by scraping, but as a rule he must depend 
entirely on the microscopic appearance of the powder. His knowledge 
gained by his study of sections and surface mounts of standard material 
will, however, be invaluable to him in interpreting the results of his exami- 
nations of powders. 

The object of this book is to aid both the student and the practical 
worker, assuming that both are familiar with the general principles of 
elementary botany, vegetable histology, and microtechnique, or at least 
are in a position to use intelligently reference works on these subjects. 

Relation to Chemical Analysis. Although the work of microscopic 
examination is distinctly botanical its chief value is in conjunction with 
chemical analysis, and for this reason is more often undertaken by the 
analyst with a moderate knowledge of vegetable histology than by the 
professional botanist. Only in large institutions can the work be divided 
among specialists. 

Both analytical chemistry and analytical histology, although widely 
unlike in their processes, are used in solving problems relating to the 
nature or purity of powdered foods, drugs, and other products of vegetable 
origin. Sometimes one line of investigation alone is useful, sometimes 
the other, but often each throws some light on the problem, thus furnishing 
an indisputable chain of evidence. 

Analytical chemistry determines the amount of fiber, starch, protein 


oil, etc. ; analytical histology, the shape, size, reactions, and other char- 
acteristics of the cells and cell-contents. Analytical chemistry usually 
stops with the mere determination of the amount of chemical constituents ; 
analytical histology goes further, and names the seeds, roots, barks, or 
other vegetable products from which the material was prepared. Ana- 
lytical chemistry answers a question in scientific terms ; analytical histology 
in terms which all can understand. 

In many cases a satisfactory idea of a material is gained only by fol- 
lowing out both lines of investigation. By chemical analysis we learn the 
percentage of protein, fiber, starch, etc., but not the ingredients from which 
they were derived; by microscopic analysis we learn the ingredients, 
but gain little idea of their proportion; but given the results of both 
analyses, we may often calculate approximately the percentage of the 
different materials present. 

If, for example, we find in ground cloves 5 per cent instead of 15 per 
cent of essential oil, and 40 per cent instead of 8 per cent of fiber, we know 
it is not pure cloves; if we find under the microscope a large amount of 
stone cells and other tissues of the cocoanut shell, we learn the adulterant. 
Knowing all this, and knowing the average percentage of volatile oil in 
cloves and of fiber in both cloves and cocoanut shells, we have the data 
for calculating roughly the percentage of each in the mixture. 

Mineral salts and other inorganic constituents of a mixture are iden- 
tified by chemical or microchemical tests, and the amounts present deter- 
mined by chemical methods. 

Elementary Botany 

Bergen: The Foundations of Botany. Boston. 

Bessey: Botany for High Schools and Colleges. New York, 1880. 

Leavitt: Outlines of Botany. New York. 

Structural Botany. 
Gray: Structural Botany. New York, 1880. 

Vegetable Histology. 
See p. 27. 

1 Works in English. 


Microscopy of Drugs. 

Greenish: Foods and Drugs. London, ioio. 

Jelljffe: Introduction to Pharmacognosy. Philadelphia, 1904. 

Ksaemek: A Course in Botany and Pharmacognosy. Philadelphia, 1910. 

Microscopy of Fibers. 
Matthews: The Textile Fibers. New York, 1913. 

Technical Microscopy. 

Hanausek (Trans, by Winton) : The Microscopy of Technical Products (Starch, 

Textiles, Paper, Wood, Leaves, Barks, Bone, Horn, etc.). New York, 1915. 
Winslow: Elements of Applied Microscopy. New York, 1905. 

Chemical Microscopy. 
Chamot: Elementary Chemical Microscopy. New York, 1915. 

Chemistry of Foods. 

Battershall: Food Adulteration and its Detection. New York, 1887. 

Bell: The Chemistry of Foods. London, 1881. 

Blyth: Foods, their Composition and Analysis. London, 1903. 

Hassall: Food, its Adulteration and the Methods for their Detection. London, 

Leach: Food Inspection and Analysis. New York, 1914. 
Leffmann and Beam: Select Methods of Food Analysis. Philadelphia, 1905. 
U. S. Dept. Agr., Bur. Chemistry, Bulletins, 13, 46, 65, and 107. 


It is beyond the province of this work to describe the construction of 
the microscope and microscopic apparatus, or give instructions for their 
care and use. Those who desire information of this nature are referred 
to the works named on p. 19 and the pamphlets issued by the leading 
makers of instruments. 

The list of apparatus which follows is designed merely as a guide 
for the purchaser. 

Essential Apparatus. The apparatus described under this head is 
essential for the most elementary work in food microscopy; on the other 
hand, it is sufficient for verifying nearly all the descriptions in this 
volume, and for undertaking most of the problems encountered in prac- 
tical work. 

Compound Microscope. The stand should be of the Continental 
type, and should be provided with two objectives, a double nose-piece, 
two eye-pieces, an eye-piece micrometer, and a substage diaphragm. 

A satisfactory range in magnification is secured by £ and £ objectives 
and 1- and 2-inch eye-pieces, of English and American makers, or Nos. 2 
and 6 objectives and II and IV eye-pieces of Continental makers. 

A simple form of eye-piece micrometer is suited for our purpose. It 
may be calibrated by means of a stage micrometer. 

The double nose-piece, enabling the worker instantly to change from 
one objective to the other, is an inexpensive convenience that adds so much 
to the utility of the instrument that it may be regarded as a necessity. 

For ordinary work the only substage attachments needed are the 
mirror and a simple diaphragm, but the substage should be of such a 
construction as to permit the introduction of a substage condenser and 
an iris diaphragm. 



Simple Microscope, A pocket lens will answer the purpose, but an 
instrument with a stage and adjustable arm for the lenses is much more 

Turn-table with centering pins for ringing permanent mounts. 

Section Razor. This should be plano-concave and have a keen, 
thin edge for cutting soft tissues. Another razor with a stronger edge 
is useful for cutting hard materials. 



Dissecting-needle Handles with interchangeable needles. 


Forceps with fine points. 

Slides of the usual size (3X1 inch) may be obtained either of thick 
or thin glass, as preferred. 

Cover-glasses. No. 2 round cover-glasses J inch in diameter are 
recommended for both temporary and permanent mounts. 

Reagent Bottles with stopper pipettes ground into the neck. 


Supplementary Apparatus. The following accessories, although not 
essential for ordinary work, should be in every well-appointed microscopi- 
cal laboratory. 

A Substage Condenser with an iris diaphragm attached is valuable 
in securing sufficient illumination on dark days. 

Polarizing Apparatus. 1 This apparatus is useful chiefly in the exami- 
nation of starch grains, crystals, and thickened cell-walls. It consists 
of two Nicol prisms, one (the polarizer) mounted in the substage, the 
other (the analyzer) in the tube or above the eye-piece. Selenite plates 
for use with the polarizing apparatus may be mounted either in a revolving 
disk in the substage, or in a metal slip for use on the stage under the 

A Mechanical Stage is of service in examining systematically every 
portion of a mount. A detachable form is recommended, as there are 
many times when this attachment is a hindrance rather than a con- 

Microtome. This instrument is of value in preparing uniformly thin 
sections, particularly of soft tissues. In preparing a series of sections 

•A convenient micropolariscope, arranged for instantly changing from plain to 
polarized light and vice vorsa, has been described by the writer. Jour. Appl. Micros 
1899, 1, 51. 


it is invaluable. It is, however, an instrument for special investigation, 
and not for practical food examination. 

Paraffine Bath. For use in paraffine embedding. 

Camera Lucida. Useful in making drawings. 

Photomicrographic Apparatus. This is especially useful in preparing 
exhibits for court cases. 


The following reagents comprise all that are needed for practical 
work. Others which are useful in special investigations are described 
in Strasburger's and Zimmerman's works. (See Bibliography, p. 19.) 

Acetic Acid. Glacial or 99 per cent acetic acid diluted with 2 parts 
of water. 

Alcohol. In dehydrating preparations for mounting in xylol balsam,, 
absolute alcohol is used, but for preserving, hardening, and most other 
purposes ordinary 95 per cent alcohol meets every requirement. 

Alcanna Tincture. Macerate 20 grams of alkanet root for severaL 
days with 100 cc. of water. Dilute with an equal volume of water as used. 

Ammonia Water. The concentrated solution containing about 30 
per cent of ammonia gas is used in making Schweitzer's reagent and for 
some other purposes. For the turmeric test the concentrated solution 
should be diluted with 10 parts of water. 

Canada Balsam in Xylol. The solution prepared ready for use may 
be obtained of all dealers in microscopic supplies. 

Chloral Hydrate Solution. Dissolve 8 parts of chloral hydrate in 5 
parts of water. See also p. 185. 


Chlorzinc Iodine Solution. Treat an excess of zinc with hydrochloric 
acid, evaporate to a specific gravity of 1.8, and filter through asbestos- 
As needed, saturate a small portion of the sirupy liquid first with potas- 
sium iodide and finally with iodine. 

The solution may also be prepared by dissolving 30 grams of zinc 
chloride, 5 grams of potassium iodide, and 0.89 gram of iodine in 14 cc. 
of writer. To prevent deterioration keep a few crystals of iodine in the 


Ferric Chloride. Dissolve 1 part of the salt in 100 parts of water. 

Fehling Solution. I. Dissolve 173 grams of crystallized Rochelle- 
salts and 125 grams of caustic potash in water and make up to 500 cc. 
II. Dissolve 34.64 grams of crystallized copper sulphate in water and 
make up to 500 cc. Mix equal parts of I and II as needed. 



Glycerine. For use as a mounting medium, dilute with an equal volume 
of water. 

Glycerine Jelly (Kaiser's). Soak i part of finest French gelatine 
2 hours in 6 parts of distilled water. Add 7 parts of glycerine, and to 
each 100 grams of the mixture, 1 gram of strongest carbolic acid. Warm 
for 10 to 15 minutes with constant stirring, until the flakes from the car- 
bolic acid disappear. Filter through previously moistened glass wool. 
Warm as needed, and remove with a glass rod. Glycerine jelly is sold 
by all dealers. 

Glycerine Gum. Dissolve 10 grams of gum arabic and 2 grams of 
glycerine in 10 cc. of water. 

Hydrochloric Acid, Concentrated. 

Iodine in Potassium Iodide. Dissolve 0.05 gram of iodine and 0.2 
gram of potassium iodide in 15 cc. of water. 

Iodine Tincture. Dissolve in 95 per cent alcohol sufficient iodine 
to make a light coffee- colored solution. 

All iodine solutions deteriorate on keeping, particularly if exposed 
to the light. 

Labarraque's Solution (chlorinated soda). Thoroughly triturate 75 
grams of fresh chlorinated lime (bleaching-powder) with 600 cc. of water, 
added in two or three successive portions, and filter. To the filtrate 
add a solution of 150 grams of crystallized sodium carbonate in 400 cc. 
of water, mix thoroughly, warm if the solution gelatinizes, and again 

The solution gradually loses strength on standing, and should be 
kept in stoppered bottles in a cool, dark place. 

Javelle Water (chlorinated potash) may be prepared in the same 
manner, substituting 58 grams of potassium carbonate for the sodium 
carbonate. This reagent is used for the same purpose as Labarraque's 

Millon's Reagent. Dissolve metallic mercury in an equal weight of 
concentrated nitric acid and dilute with an equal volume of water. The 
solution should be freshly prepared. 

Nitric Acid, Concentrated. 

Olive Oil. 


Phoroglucin Tincture. Dissolve 0.1 gram in 10 cc. of 95 per cent 
alcohol. The solution deteriorates on keeping. 

Potash Solution. Dissolve 5 grams of caustic potash (potassium 


hydroxide) in ioo cc. of water. If desired, caustic soda may be substituted 
for caustic potash. 

The term "alkali" as used in this work refers to one or the other of 
these solutions. 

Safranin Solution. Prepare a saturated water solution, and dilute as 

Schultze's Macerating Mixture. Mix a few crystals of potassium 
chlorate with concentrated nitric acid immediately before using. 

Schweitzer's Reagent ("ammoniacal copper solution," "cuprammonia," 
"cuoxam"). Precipitate cupric oxyhydrate from a solution of copper 
sulphate by adding a slight excess of caustic soda or ammonia, filter and 
thoroughly wash. Dissolve the moist precipitate in strong ammonia 
with the aid of heat, cool, and filter from the precipitate which forms. 
It should be freshly prepared, and kept in the dark. 

Soda Solution. Five per cent solution of caustic soda (sodium hy- 
droxide) may be substituted for potash solution as a clearing agent. In 
the crude-fiber process, and for removing dark coloring matters, if per cent 
solution is used. 

Sulphuric Acid. The concentrated acid is employed in several tests. 
It should be diluted to i\ per cent for use in the crude-fiber process. 

Turpentine (spirits or oil of turpentine). 



A collection of the vegetable materials used as foods or food adulterants 
and mounts of such materials are as indispensable to the food microscopist 
as is an herbarium to a systematic botanist. Many points of structure and 
special reactions can be learned with the aid of such collections which 
cannot be properly described in words or illustrated by figures. 

Standard Materials. The collection should include not only the 
fruits, seeds, barks, leaves, rhizomes, flowers, and other whole materials, 
but also the various products prepared from them. Many of these may 
be obtained from grain dealers, grocers, seedsmen and pharmacists, 
others may be collected in the field or garden. Powders are conveniently 
stored in screw-top bottles, which have the advantage over glass- or cork- 
stoppered bottles that they more completely exclude dust. Fruits, vege- 
tables, and other succulent materials are preserved in alcohol or formalde- 
hyde. Especially useful is the collection of economic seeds prepared under 
the direction of Frederick V. Coville, Botanist of the United States Depart- 
ment of Agriculture, by Gilbert H. Hicks, also the cabinet of materia 
medica specimens supplied by Parke, Davis and Company, Detroit, 
Mich., U. S. A. 

Microscopic Mounts. Powders such as flour, meal, and starch are 
best mounted in water as occasion demands, but sections and other diffi- 
cultly prepared specimens should be at hand in permanent form. The 
collection of mounts may be prepared either by the microscopist himself, 
or by a skilled worker from material of his selection. At present suitable 
collections of mounts are not on the market 



Cross-sections. In studying standard material cross-sections are 
indispensable, as they show the number and arrangement of the cell 
layers and certain details of structure. Longitudinal and tangential sec- 
tions are of lesser importance. Sections are also useful in the examina- 
tion of coarsely ground commercial products, such as ground coffee and 
other materials containing fragments large enough for cutting. It should 
be remembered, however, that, sections play a comparatively unimpor- 
tant role in diagnosis, as most of the materials which the microscopist is 
called upon to examine are fine powders and other preparations in which 
the tissues have been torn one from another, and can only be studied in 
surface view or as isolated elements. 

Considerable discretion is required in the treatment preliminary to the 
cutting of sections. As a rule, dried materials are best cut after soaking 
in water for some hours or until thoroughly softened, although cruciferous 
seeds and some other materials are best cut dry. Succulent fruits and 
other fresh materials should be hardened in 50 per cent alcohol. Only 
in the investigation of very delicate tissues is it desirable to resort to the 
tedious process of impregnating with parafnne or collodion. 

Large objects are held between the thumb and first finger during cut- 
ting, small objects between pieces of elder pith, sticks of soft wood, or 
in a hand vise, or else they are embedded in parafnne jor glycerine gum. 
Wood for holding materials during cutting should be sawed across the grain 
into sticks so that the razor or microtome knife will cut with the grain. 

Glycerine gum is used not merely to embed the object, but also to 
attach it to a piece of elder pith. The sections are cut after the gum 
has hardened. 

Parafnne may be used not only for dry materials, whether or not 
impregnated with parafnne as described below, but also for fresh material 
or material softened in water, provided the outer surface is carefully dried 


to insure contact. It should have a melting-point of 54° or 74 C, and 
is conveniently molded into sticks by melting at the lowest possible 
temperature and pouring slowly into a glass or metal tube. The stick 
may be loosened from the tube by gentle heating. The object is introduced 
into a cavity in the end of th« stick, and the paraffine melted about it 
with a hot wire or needle. 

The section razor used for cutting soft objects should have a keen, 
thin edge, but for cutting nut shells and other hard tissues another razor 
with a beveled edge should be in readiness. Both are kept in order 
by honing and stropping. 

The microtome is a convenience but not a necessity, being used almost 
exclusively in preparing permanent mounts for the collection or in diffi- 
cult investigations. Many food microscopists use only a razor. 

Impregnating and Embedding with Paraffine or Collodion is best carried 
out with material preserved while fresh in 50 per cent alcohol, although 
dry material may be soaked in water until the tissues are softened and 
then transferred to 50 per cent alcohol. To facilitate the process, seeds 
and small fruits should b& cut in half, and other materials in as small 
pieces as practicable. 

In carrying out the paraffine process the object is immersed successively 
in the following : 65, 80, and 95 per cent alcohol, absolute alcohol, a mix- 
ture of equal parts of xylol and absolute alcohol, xylol, a mixture of xylol 
and paraffine (melting at 43 C), 43 paraffine kept at 50°, and finally 
54 paraffine kept at 6o°. The time required for permeation in each of 
these varies, according to the size and nature of the object, from one to 
several days. Finally the object is removed from the paraffine to a suit- 
able mold, covered with melted paraffine, and allowed to cool. 

If the collodion process is followed, the object is treated with 50, 65, 
80, and 95 per cent alcohol and abs'olute alcohol as above described, but 
is removed from the latter to absolute ether, then to a mixture of ether 
and collodion, and finally to pure collodion. It is then transferred to 
a paper mould, covered with collodion, and, when the latter has 
solidified, the whole is placed in 80 per cent alcohol, where the collodion 
in some hours forms a cartilaginous mass enveloping the object. 

Sections of fruit stones and nutshells are cut with a fine saw and after 
being attached to a slide by hot Canada balsam are ground down to the 
desired thickness on a whetstone. They are finally mounted in balsam. 

Surface Sections are useful in studying epidermal tissues, fruit and seed 
coats, and other cell aggregates forming distinct layers. They are much 


easier to prepare than cut sections. Dried materials should be soaked 
in water, after which the layers may usually be removed by scraping or 
stripping. The separation of the coats from very small seeds is often 
facilitated by soaking for some hours in dilute (i J per cent) caustic soda. 
Boiling with dilute soda is sometimes desirable, particularly if the layers 
contain coloring matters which render them opaque. The epidermal 
layers of fruits can often be separated by plunging into boiling-hot water. 

The bran coats of cereals, the seed coats of legumes, and oil seeds, 
and the various layers of spices and other materials may be studied in 
fragments picked out from the coarsely ground products with forceps or 
separated by sifting. Even in quite finely ground products one often 
finds large enough fragments for studying in surface view not only the 
characters of the individual cells, but also the arrangement of the cells 
in the layers. 

The different layers in surface sections may become separated from 
one another or they may remain in their original position one on top of 
another. In the latter case it is often possible by careful focusing not 
only to study successively the layers, but also .to determine their order of 
arrangement. This is greatly facilitated by noting in preparing the 
mount whether the outer or the inner surface is uppermost, and also by 
comparison with cross-sections. Some materials which have no very 
characteristic single layer can be identified by the combination of several 
cell layers and their order of arrangement. 

Powders. Since the food microscopist is called upon to examine 
powders more often than any other class of products, he should familiarize 
himself with the microscopic characters of standard materials in powder 
form. Tissues in definite layers, such as epidermal cells, the bran coats 
of cereals, and the coats of various seeds, have much the same appear- 
ance in the ground material as in surface preparations ; except that in 
fine powders the fragments are smaller, and radially elongated elements, 
such as the palisade cells of legumes and cotton seed, often fall on their 
sides, presenting the same appearance as in cross-section. Cells not in 
layers, such as make up the endosperm of cereals and the cotyledons of 
legumes, do not present a striking appearance in powder form, although 
the contents of their cells, being liberated by the rupture of the cell-walls, 
may be studied to advantage. Stone cells, vessels, and other detachable 
elements are also striking objects in powders. 

Commercial Powders should first be examined under a simple micro- 
scope, either before or after separation into grades by sifting, and fragments 


picked out fof subsequent examination under the compound microscope. 
Mounts representing the whole material should also be made. If the 
powder is too coarse for mounting directly, it may be reduced to an im- 
palpable powder in an iron mortar, or a small portion may be crushed on 
the slide with a scalpel. 

Special instructions for the examination of flour are given on p. 52, 
of cereal cattle foods on p. 58, of ground oil cakes on p. 171, and of 
ground spices on p. 497. 

Pulps. The flesh of ripe fruits may be examined as a pulp, hard 
elements, such as vessels and stone cells, being especially distinct in such 
preparations. The same method is used for commercial jams, jellies, 
pastes, etc. 

Maceration by Schultze's* method is useful in reducing hard materials 
to a pulp, thus isolating the elements. The process consists in cautiously 
heating a small amount of the material in a capsule with concentrated 
nitric acid and a few crystals of potassium chlorate. As soon as the 
tissues are sufficiently disintegrated, the solution is diluted with water and 
the fragments washed thoroughly by decantation. 


Mounting in Water. Although water is usually regarded as an 
inert substance, it serves in microscopic work as the most important 
of all reagents ; in fact, if we had no other we would still be able to carry 
on our work with reasonable success. 

Water dissolves sugars, gums, certain proteids, and other cell-contents, 
and in addition swells and partially dissolves constituents of the cell-walls. 
Most of these soluble substances have no marked microscopic characters, 
whereas the insoluble constituents, including starch and calcium oxalate 
among cell-contents, and cellulose, lignin, suberin, and cutin of cell-wall 
constituents, occur in striking and often highly characteristic forms. 
For these reasons water is especially suited as a microscopic medium, 
although it cannot of course be used for permanent mounts. 

In the water mount we first observe whether starch is present, and 
if so, note the characters of the grains. Addition of iodine solution dif- 
ferentiates the starch grain from other bodies. We next turn our atten- 
tion to the other elements, particularly the tissues. Starch, if present 
in considerable amount, obscures the tissues, but can be converted 
into a paste and thus rendered transparent by heating the mount to boiling 


over a lamp, replacing the water lost by evaporation. This boiling, 
which takes the place of treatment with alkali, chloral, or other clearing 
agents, also renders the tissues more distinct by swelling the cell-walls. 
Air bubbles may be removed from a section by soaking in a considerable 
amount of recently boiled water. 

Treatment with Iodine colors the starch grains of water mounts blue, 
proteid matter yellow-brown, and cellulose, lignin, and other cell-wall 
substances various shades of yellow. 

The solution in potassium iodide acts more rapidly than the tincture, 
coloring the starch grains a deeper shade of blue. 

If the tincture is added directly to the dry or alcohol material, starch 
grains are colored brown-yellow, changing to blue on dilution with water. 
Treatment with iodine and then with Strong sulphuric acid colors 
cellulose blue, lignified, suberized, and cuticularized tissues yellow. Chlor- 
zinc iodine gives much the same color reactions as iodine and sulphuric 
acid, and is more convenient. The best results are secured if the prepara- 
tion is first soaked in water. 

Treatment with Oil Solvents. Products containing a large amount 
of fat, oil, or essential oil can be studied to advantage only after treatment 
with chloroform, ether, turpentine, or some other oil solvent. Sections 
may be soaked in the solvent in a covered watch-glass, and powders may 
be extracted on a filter or in a fat extractor. More convenient methods, 
provided subsequent treatment with reagents is not needed, are to mount 
the section or powder directly in turpentine, which dissolves the oil, or else 
in olive or almond oil which mix with the oil of the product. These 
methods are especially useful in the study of aleurone grains. 

Clearing. Alkalies (potassium or sodium hydrate) are the most 
serviceable clearing agents for general use. The treatment may be per- 
formed on the slide either by mounting directly in dilute alkali or bv adding 
a small drop of 5 per cent alkali to a water mount, or in the case of dark- 
colored tissues by boiling with i\ per cent caustic soda. 

Alkali dissolves starch, proteids, various coloring matters and other 
cell-contents. It also swells the cell-walls, and to some extent expands 
compressed tissues. 

Chloral Hydrate acts more slowly than potash and soda, but has the 
advantage that it does not distort greatly the tissues. 

Labarraque Solution (chlorinated soda) and Javellc Water (chlorinated 
potash) are admirable reagents for bleaching tissues and expanding com- 
pressed cells. They are particularly adapted for sections, but owing to 


the difficulty of removing the bubbles, are less suited for powders. Sec- 
tions should be soaked in the reagents (diluted if necessary) until the 
desired result is attained, and then washed in water and finally in very 
dilute acetic acid. They become so transparent by this treatment that 
staining with safranin or some other dye is usually essential. 

Crude Fiber Method. This process serves not merely for the quan- 
titative determination of crude fiber, but also for clearing the tissues 
for microscopic examination. After weighing the crude fiber a small 
quantity may be removed for examination without introducing a per- 
ceptible error in the subsequent determination of ash. The action is 
so energetic as to destroy delicate tissues; but is valuable in clearing stone 
cells and other sclerenchyma elements. 

The process (which may be abbreviated if used merely for clearing) 
is as follows: Extract 2 grams of the finely ground material with ether, 
place in a 500 cc. Erlenmeyer flask, and add 200 cc. of boiling 1.25 
per cent sulphuric acid. Loosely cover the flask, heat at once to boiling, 
and boil gently thirty minutes. Filter on a paper, wash with hot water, 
and rinse back into the same flask with 200 cc. of boiling 1.25 per cent 
sodium hydroxide solution nearly free from carbonate. After boiling, 
as before, for thirty minutes, collect the fiber on a weighed paper, thor- 
oughly wash with hot water, and finally with a little alcohol and ether. 
Dry to constant weight at ioo° C, and weigh. Deduct the amount 
pf ash in the fiber, as determined by incineration, from the, total 

Staining. Great numbers of stains have come into use for staining 
cell-walls and cell-contents. 

Safranin, a stain strongly recommended by Strasburger, has the advan- 
tage over most other stains in that it differentiates very beautifully the 
tissues, and does not, like most coal-tar colors, fade in glycerine mounts. 
The best results are secured by soaking the section for some time in a 
rather dilute water solution. Overstaining, with subsequent removal 
of the excess with alcohol, is often advantageous. 

Treatment with Other Reagents is carried on in a watch-glass, or on the 

slide, as occasion demands. In the latter case the material is either 

treated directly with a drop of the reagent, or it is first mounted in water, 

and a drop of the reagent is drawn under the cover-glass by mean's of a 

-piece of filter-paper placed on the opposite side. 

Sections of impregnated material are attached to a slide by means 
of Meyer's albumen fixative, then soaked in chloroform or xylol until 


the paraffine is dissolved, and finally treated with reagents and stains 

ad libitum. 

Permanent Mounting. The technical microscopist, as well as the 
investigator, often has occasion to mount in permanent form objects 
of special interest. If the material contains a large amount of oil, or if 
it has been impregnated ' with paraffine, these should be removed by 
treatment with chloroform, xylol, or other oil solvent. Objects which 
have been cleared with alkali or Labarraque's solution should be washed 
thoroughly in water and finally in very dilute acetic acid. Most other 
reagents can be removed by water or alcohol. Staining is advisable if 
the tissues are both colorless and transparent, and is essential if Canada 
balsam is employed as the mounting medium. Air bubbles may be re- 
moved by boiling or allowing to soak in a considerable bulk of freshly 
boiled water. Slides and cover-glasses must be scrupulously clean and 
free from finger prints. 

The process of mounting is quite simple. A suitable sized drop of 
the mounting medium is placed in the center of the slide, the object is 
transferred to this, and the cover-glass is placed in position by means 
of forceps. If too much of the medium is used, the excess is removed 
with a piece of filter-paper; if too little, more is added from one side. 
The mount is finally ringed with two or more coats of cement. 

It is well to keep the slide on the turn-table not only during ringing, 
but also while mounting, thus facilitating the centering of both object 
and cover-glass. 

Mounting in Glycerine. A mixture of equal parts of glycerine and water 
is the best single medium for our purpose, since wet objects may usually 
be mounted directly without staining or dehydrating, and can be removed 
at any time for further treatment with reagents. 

The mounting is greatly facilitated by so gauging the size of the drop 
that it exactly fills the space beneath the cover-glass. If more is added, 
or an excess removed, care should be taken to clean thoroughly the slide 
about the cover-glass with a filter-paper, otherwise the cement will not 
stick to the glass. The mount should be ringed two or three times with 
a good cement, allowing it to dry at least 24 hours between the coats. 1 

Mounting in Glycerine Jelly requires less skill than mounting in glyc- 
erine, but the heating necessitated by the process injures some materials, 

1 The writer uses "King's Transparent Cement" for the first coat, and "King's Lacquer 
Cell and Finish" (red or blue) or "White Zinc Cement" for the finishing coats, the three 
colors being used to distinguish respectively cross, surface, and longitudinal sections. 


and, furthermore, the objects are not so readily removed should occasion 

A small cube of the solid or a drop of the melted jelly is placed on the 
slide and heated gently until fluid throughout. The object, which may 
be taken from water or glycerine, is then introduced, and the cover-glass, 
previously warmed to prevent introduction of air bubbles, is placed in 
position. After cooling, the excess of the jelly should be carefully removed, 
and the mount ringed, as described for glycerine mounts. 

Mounting in Canada Balsam can be carried out only with objects freed 
from water. Dehydration is effected by soaking in 95 per cent alcohol, 
absolute alcohol, and finally in xylol, chloroform, or oil of cloves. Stain- 
ing is essential for objects with colorless tissues. 

A drop of the xylol balsam is placed in the center of the slide, the 
object is introduced, and the whole is covered with a slightly warmed 
cover-glass. More balsam is added if, after standing, the space under 
the cover-glass is not entirely filled. After the balsam has thoroughly 
hardened, the excess may be removed and the mount ringed with colored 
cement; this, however, is not essential, for the mount is permanent with- 
out it. 


Behrens: Guide to the Microscope in Botany (Trans, by Hervey). Boston, 1885. 

Chamberlain: Methods in Plant Histology. Chicago, 1915. 

Lee: The Microtomist's Vade Mecum. Philadelphia, 1900. 

Strasbtjrger and Hillhotjse : Handbook of Practical Botany. London, 1900. 

Zimmermann: Botanical Microtechnique (Trans, by Humphrey) New York, 1901. 

1 Works in English. 



Parenchyma (Fig. i) is a general term for the simpler forms of tissues, 
with thin walls composed usually of cellulose. The common types of 
parenchyma cells are either isodiametric or somewhat elongated, and 
may or may not have intercellular spaces at the angles. If the walls are 

Fig. i. Parenchyma from the stem of maize, gw double wall between two cells; z inter- 
cellular space produced by splitting of the double wall. (Sachs.) 

of cellulose, chlorzinc iodine colors them blue and Schweitzer's reagent 
dissolves them. 

Spongy Parenchyma (Fig. 2) is a loose spongy tissue with numerous 
intercellular spaces of considerable size. 

Collenchyma (Fig. 3) is characterized by conspicuous thickenings at 
the angles of the cells. The cell-wall is composed of cellulose, or a modi- 
fication known as collenchym. This form of tissue occurs most com- 
monly in subepidermal layers. 

Sclerenchyma includes a great variety of tissues with thickened walls 
composed chiefly of lignin. The walls of these cells as first formed 
are pure cellulose, lignin being deposited on the inner surface of the 
walls during subsequent growth. Chlorzinc iodine colors the walls yellow 


or yellow- brown ; phloroglucin and hydrochloric acid, pink; aniline sul- 
phate, deep yellow. 

Stone Cells (Fig. 4) are isodiametric, or moderately elongated seleren* 
chyma elements, with thickened walls and conspicuous pores. They 
occur either singly or in groups in parenchyma, or form dense tissues, 
such as the shell of the cocoanut and the stone of the peach. 

FlG. z. Spongy Parenchyma from the hull Fig. 3. Epidermis and Collenchyma 
(spermoderm) of the common pea. from the petiole of Begonia, v 

(Moeller.) thickened wall of collenchyma; chl 

chlorophyl grains. (Sachs.) 

Sclerenchyma Fibers (Fig. 5) occur in various parts of plants. Those 
found in fibro-vascular bundles are known as Bast Fibers. 

Other sclerenchyma tissues are found in stems, leaves, the coats of 
fruits and seeds, and in various organs. 

Epidermal Tissues have certain characteristics peculiar to their posi- 
tion. They are usually covered by a membrane known as the "cuticle," 
composed of cutin, a substance related to lignin and suberin. Wax, 
silica, calcium carbonate, and calcium oxalate also occur as epidermal 

Stomata are made up of peculiarly differentiated epidermal cells. 
(See pp. 28-30.) 

Hairs and Glands, including many beautiful and characteristic forms, 
are unicellular or multicellular outgrowths of epidermal layers. > ' 



Cork Cells form protective layers on stems and other parts. The 
cells are arranged in radial rows, and are polygonal in surface view, quadri- 
lateral in section. Suberin, the characteristic constituent, is repellent of 

Fibro-vascular Bundles (Figs. 6 and 25). The conducting elements 
of plants are commonly grouped into vascular or fibro-vascular bundles, of 
which the nerves of leaves and the strands of stems and roots are examples. 

Fig. 4. 

Stone Cells from the shell of the 
cocoanut. (Winton.) 

Fig. 5. Bast Fibers from the bark 
of Sambucus nigra. (Vogl.) 

A bundle is made up of two distinct parts: (1) the xylem, wood or had- 
rome, consisting of vessels, tracheids, and other lignified elements, and 
(2) the phloem, bast or leptome, consisting of sieve tubes, cambiform 
cells, and other non-lignified elements. 

Groups of bast fibers usually accompany the bundles. 

For details as to the arrangement of xylem and phloem see pp. 39-45. 

The Vessels of the xylem, also known as ducts and trachea, are thin- 
walled tubes with annular, spiral, scalariform or reticulated thickenings, 
or thick-walled tubes with pits or pores. 

Tracheids resemble vessels in their markings, but consist of rows of 
cells placed end to end, not open tubes. 




Sieve Tubes, the characteristic elements of the phloem, are thin-walled, 
elongated cells, with perforated transverse partitions known as sieve plates. 
These sieve plates also occur to some extent on the longitudinal walls. 
Both the sieve tubes and the accompanying cambiform cells are com- 
posed of cellulose. 

Bast Fibers (Fig. 5) are long, pointed cells with lignified walls. Pores 
through which pass diagonal, crossing fissures are usually evident. 

Fig. 6. Fibro-vascular Bundle from the mesocarp of the cocoanut, in longitudinal section. 
ste stegmata; Si silicious body; / bast fibers; t tracheids with- small pits; I' tracheids 
with large pits; sp spiral vessel; r reticulated vessel; sc scalariform vessel; s sieve 
tube; c and c' cambiform cells. (Winton.) 

Latex Tubes (Fig. 341). These are branching tubes containing milky 
secretions, found in various stems and roots, and occasionally in fruits. 


Protoplasm, the living matter of the vegetable cell, includes: (1) cyto- 
plasm, which in the growing stage is a viscous, stringy, more or less granu- 
lar substance, but in the dried material has no marked characters ; (2) the 
cell nucleus, a rounded body differentiated by staining and often evident 
.. without; and (3) the plastids or chromatophores, including the chloro- 
plasts, leucoplasts, and chromoplasts. 

Chloroplasts, or chlorophyl grains, occur in all green parts, and play 
an important r61e in assimilation (p. 29.) 

Leucoplasts are inconspicuous, colorless bodies instrumental in the 
formation of starch (p. 644). 



Chromoplasts are orange or yellow bodies of various shapes to which 
certain organs owe their distinctive color. 

Proteins occur either in amorphous form or as aleurone grains. On 
heating with Millon's reagent they form a reddish deposit; on treatment 
with iodine solution they are colored yellow or brown. 

Aleurone Grains (Fig. 7) are found in the perisperm, endosperm, and 
embryo of seeds, particularly oil seeds, and like starch grains have marked 

Fie. 7. Aleurone Grains; in the center two cells filled with aleurone grains. (T. Harhg.) 

microscopic characters, which are often characteristic of the species 
or genus. These grains vary in size from less than 1 fi to over 50 //. 
Among the numerous shapes are round, oval, irregularly swollen, angular, 
and warty forms. They are colored yellow or brown by iodine solution 
and take up readily certain aniline dyes, haematoxylin, and other stains. 
Being partly soluble in water, they should be mounted either in glyc- 
erine after extraction of the oil in which they are often embedded, or 
directly in oil or turpentine. Each grain consists of a ground substance, 
in which are usually embedded one or more crystalloids, one or more 
globoids, and often a crystal rosette of calcium oxalate, the whole being 
inclosed in a thin membrane. 

1. The ground substance consists of amorphous protein matter, and is 
usually soluble in water, although after previous standing in alcohol it 
dissolves slowly. It is also soluble in dilute alkali, acids, and various 
reagents, but is not affected by oil or oil solvents. 

2. Crystalloids are proteid crystals belonging to the isometric or hex- 
agonal system. In some species they are so large that a single crystalloid 
makes up the bulk of the grain, in others they are very minute. For the 
most part they are insoluble in cold water, but dissolve in very dilute alkali 
(less than 1 per cent), dilute acetic or hydrochloric acid. They are insol- 


ubie in saturated solution of picric acid (distinction from globoids) and 
in saturated solution of sodium phosphate (distinction from all other con- 
stituents of the. grains). 

3. Globoids, according to Pfeffer, consist of lime and magnesia combined 
with phosphoric acid and an organic acid. They are usually globular, 
of uniform transparent structure, and are not colored by iodine solution. 
They are insoluble in both cold and hot water, but unlike crystalloids are 
soluble in saturated solutions of picric acid and sodium phosphate and 
insoluble in dilute potash. 

4. Calcium oxalate occurs as single crystals or as crystal rosettes. 
These are insoluble in water, alkali, and acetic acid, but dissolve readily 
in dilute hydrochloric acid. 

Alkaloids are nitrogenous substances, often with marked stimulating 
or toxic properties. Some, such as morphine and piperine, are crystalline 
solids, others, such as nicotine, are liquids. Caffein and theobromin are 
often classed as alkaloids. 

Starch. See pp. 643-650. 

Sugars occur in solution in certain stalks, roots, and fleshy fruits, and 
in the form of crystals in dried fruits. Crystals are readily seen in alcohol 
or glycerine mounts of raisins, figs, dates, etc. 

Cane-sugar crystallizes in monoclinic prisms; It does not reduce 
Fehling solution. 

Invert-sugar consists of equal parts of dextrose and levulose, and is 
formed by the splitting up or "inversion" of cane-sugar. In many fruits 
both cane- and invert-sugar are present, although as a rule the large fruits 
contain much more cane-sugar than the small fruits. As both dextrose 
and levulose are reducing sugars, they are detected by heating the dry 
object to boiling in a drop of Fehling solution diluted with two drops of 
water. The red precipitate of copper suboxide thus formed is often 
evident to the naked eye. 

Other sugars occurring in plants are rafinose, mannit, dulcit, melitose, 

Inulin is a water-soluble carbohydrate found in the roots of the dande- 
lion and other composite plants. In alcohol material it forms sphaero- 
crystals; in dried material, colorless, irregular lumps. 

Gums. These include various mucilaginous substances, some of which 
are formed in the cell, others are derived from the cell-walls. They swell 
in water and are precipitated by alcohol. 

Glucosides are compounds of sugars with organic acids. Some of 



them, such as hesperidin, form needle-shaped crystals insoluble both in 
water and dilute acids. 

Tannins are themselves colorless, but are usually associated with 
brown coloring substances. In the fresh material they are in solution, 
but on drying they impregnate the tissues or form brown deposits. With 
iron salts they become dark blue or green. 

Fats and Fatty Oils rank with carbohydrates and proteids in impor- 
tance. They occur in all parts of the plant, but are especially abundant 
in certain seeds, where they serve as reserve material. The fats may form 
amorphous masses, or beautiful crystals, while the oils occur as globules. 
Both are soluble in ether, chloroform, benzine, turpentine, and xylol, and 
form soaps with alkalis. With few exceptions they are insoluble in alco- 
hol. On treatment for some hours with alcanna tincture, all fatty sub- 
stances, as well as resins and essential oils, take on a beautiful red color. 

Waxes are closely related to fats. 

Essential Oils and Resins are formed in glands or secretory cavities, 
and are distinguished from fats and fatty oils by their solubility in alcohol. 


Fig. 8. Crystals of Calcium Oxalate, a large single crystal; e crystal rosette or cluster; 

b intermediate form. (Kny.) 

Calcium Oxalate. Lime is one of the elements essential for plant 
growth, its chief function being to render poisonous oxalic acid harmless 
by conversion into insoluble calcium oxalate. Monoclinic, or rarely 
tetragonal, crystals of this salt occur in certain tissues, and are often of 
great service in diagnosis. Four distinct forms deserve special mention : 
(i) crystal clusters or rosettes (Fig. 8, b and c), ( 2 ) large single crystals 
(Fig. 8, a), (3) raphides or needle-shaped crystals (Fig. 9), and (4) crystal 
sand or deposits of numerous minute crystals (Fig. 10). 



Calcium oxalate is distinguished from all other crystalline substances 
by its insolubility in water, alkali, and acetic acid, its solubility without 

Fig. 9. Raphides of Calcium Oxalate 
from the flesh of the pineapple. 

Fig. 10. Crystal Sand of Calcium Oxalate 
from the leaf- of belladonna. (Winton.) 

effervescence in dilute hydrochloric acid, and the formation of crystals of 
calcium sulphate with sulphuric acid. 

Calcium Carbonate is present in certain plants as concretions or 
cystoliths (.Fig. 169, cy), less often as crystals. It dissolves in dilute 
hydrochloric acid with effervescence. 

Silica forms an incrustation on certain epidermal tissues, and less often 
occurs as warty bodies in peculiar cells known as stegmata (Fig. 6, Si). 


De Bary: Comparative Anatomy of the Vegetative Organs of the Phanerogams and 

Ferns (Trans, by Bower and Scott). London, 1884. 
Goodale: Physiological Botany. I. Outlines of the Histology of Phaenogamous Plants. 

New York, 1885. 
Strasburger, Noll, Schenck, and Schimper: A Text-book of Botany (Trans. 

by Porter and revised by Lang). London, 1914. 

1 Works in English. 



Leaves are specially developed for carrying on three processes: (i) 
assimilation (photosynthesis), or the formation of organic matter through 
the agency of light from carbonic acid and water, with exhalation of 
oxygen; (2) respiration, or the oxidation of organic matter, with exhala- 
tion of carbonic acid; and (3) transpiration, or exhalation of water drawn 
up from the soil. As a rule they expose a large surface to the air, and have 

FlG. 11. Leaf in Cross Section of Marshmallow (Althcea officinalis), e upper epidermis; 
p palisade cells and p' spongy parenchyma of the mesophyl; e' lower epidermis; k 
hairs; d glandular hairs; st stomata; K calcium oxalate rosette. (Vogl.) 

special adaptations for facilitating or preventing communication with the 

air, according to the needs of the plant. 

A cross-section of a leaf (Fig. 11) shows that it is made up of a middle 

layer or mesophyl of green tissues with a network of veins, between two 

colorless cuiicularized epidermal layers. 




The Lower Epidermis (Fig. 12) consists of ground cells interspersed, 
with stomata, and often with hairs or glands. The ground cells in surface 
view differ greatly in character according to the species. Some are sharply 
polygonal, or quadrangular, with straight walls, others have ill-defined 
angles and wavy walls, and others still are irregular in outline. The 
walls may be thin or thick, porous or non-porous; the cuticle smooth or 

Stomata are slits between two hemi-elliptical guard cells, which when 
open allow free access of air to the mesophyl. In some leaves two or more 
modified cells, known as accompanying cells, adjoin the guard cells. The 

Fig. 12. 

Epidermis with Stomata from the leaf of Hydrangea Hortensia, in surface view. 

guard cells of the stomata are the only cells of the epidermis containing 
chlorophyl grains. 

In addition to ordinary or air stomata a larger form known as water 
stomata occurs on some leaves. 

Hairs and Glands (secretory hairs) present an endless variety of beau- 
tiful and characteristic forms. All hairs whether unicellular or multi- 
cellular are epidermal outgrowths, but Emergences are made up of tissues 
belonging both to the epidermis and the mesophyl. 

The Mesophyl in the under part of the leaf forms a spongy parenchyma, 
(Fig. 11, p') thus facilitating assimilation, respiration and transpiration, 
but in the upper part it is a close tissue, often consisting of one or more 
layers of palisade cells (p.). 

Chlorophyl grains are present in all the mesophyl cells, but are most 
abundant in palisade cells of the upper layers (Fig. n, p). They are 
rounded bodies varying up to 12 /i in diameter. They consist of granules 
(some green, others colorless) , proteid matter and starch grains, embedded 
in a ground substance and surrounded by a membrane. During assimila- 


tion starch is continually being formed in these grains, but is soon dis- 
solved and translocated to other parts of the plant. In dried leaves the 
chlorophyl grains are more or less brown in color, and lack distinct char- 

The Fibro-vascular Bundles of leaves are strongly developed in the 
midribs and main branches, but in the smaller branches are rudimentary. 
Spiral vessels are particularly abundant. Other elements which may 
occur in the mesophyl are stone cells, crystal cells, resin cavities, oil cells, 
latex tubes, etc. 

The Upper Epidermis may or may not be similar to the under epidermis 
in structure, but as a rule stomata are less abundant or absent. 

Preparation of Materials. 

Sections are cut with a razor, holding the leaf between pieces of pith. 
In the case of thin leaves it is advisable to cut into several strips, place 
one on the other, and section all together. Pieces of the epidermis are 
readily stripped off from moist leaves with forceps. In powdered leaves 
the elements are isolated by squeezing under the cover-glass. 


Although the four parts of the flower — sepals, petals, stamens, and 
pistils — are metamorphosed leaves, usually only the sepals, less often both 
sepals and petals, resemble leaves in outward appearance and structure. 

Calyx. The sepals, like leaves, consist of mesophyl between two 
epidermal layers. Stomata and often hairs are developed on one or 
both epidermal layers. The mesophyl parenchyma usually contains 
chlorophyl, but a well-developed palisade layer is seldom present. Bundles 
are more or less strongly developed. 

Corolla. The petals are of various colors and commonly of delicate 
texture. Each consists of two epidermal layers and a middle tissue of 
elongated parenchyma (corresponding to the chlorophyl parenchyma of 
leaves) through which pass delicate bundles. Stomata are usually lack- 
ing, but hairs and papilla? are often present. Spiral vessels, and less often 
crystal fibers, are present in the bundles. The coloring matter of the 
fresh petal is usually dissolved in the cell-sap, seldom in the form of chro- 
moplasts.^ The perfume of flowers is due to essential oils present in the 
cell-sap, in special cavities (nectaries), or in glands 


3 1 

Stamens. Each consists of a slender, cylindrical (less often flattened, 
leaf-like) filament, bearing at the apex an anther with a pair of pollen 
sacs on each side of the central bundle (Fig. 13). On ripening, the sacs 

Fig. 13. Anther of Datura Stramonium in cross section, c connective tissue with fibre- 
vascular bundle; a outer pollen sacs; p inner pollen sacs. (FranKi) 

of each pair unite, and finally the wall opens by a slit or pore, liberating 
the pollen grains. 

The walls of the anthers (Fig. 14) are composed of an outer layer 

Fig. 14. Anther Wall in cross 
section showing the outer 
epidermis and the endothe- 
cium with reticulated walls. 

Fig. 15. Pollen Grains, i, 2 heath; 3, 4 linden; 
5 blueberry; 6, 7 marjoram; 8, 9 lavender; 10, 
11 sage; 12, 13 balm; 14, 15 rosemary; 16, 17 
flax; 18 white mullein; 19, 2omelilot; 21 willow 
herb; 22, 23 composite plants. (Villiers and 

or epidermis, sometimes hairy, and an endothecium or inner layer of char- 
acteristic cells with narrow radial ribs forming reticulations. 

3 2 


Pollen Grains (Fig. 15) are mostly globular, rounded, or tetrahedral, 
either smooth or else covered with warts, bristles, or pits. They consist 
of single cells clothed with two membranes ; the outer thick, forming a 
kind of cuticle; the inner thin, forming the cell-wall proper. The con- 
tents consist of protoplasm, often with, granules in suspension. When 
the ripe pollen is deposited on the stigma the protoplasmic contents burst 

Fig. 16. Pollen Grains and Crystals of Cane-sugar irom Honey, a pollen grains of furze: 
b oi heath; c of some composite flower. (Hassall.) 

out through clefts, or more commonly through pores, forming tubes whidr 
penetrate through the tissues of the stigma and style into the ovule, effect- 
ing fertilization. The shape, size, and markings of pollen grains are 
often so characteristic as to permit the identification of the species, not 
only in powders, but also in honey, thus furnishing evidence a. to the 
flowers visited by the bee (Fig. 16). 

The Pistil (Fig. i 9 ) consists of stigma, style, and ovary, the latter 
enclosing the ovules. The stigma is clothed with clammy" papilte, on 
which the pollen grains lodge. The style is long or short, with a central 



■channel. It is made up of elongated elements. The ovary walls are 
of quite simple structure, but the fruits into which they ripen are often 


A fruit in its simplest form is a ripened pistil, consisting of pericarp or 
matured ovary wall, and one or more seeds or matured ovules. In some 
fruits, notably the apple and other pomes, the fruit flesh is developed from 

Fig. 17. Cocoanut Fruit. 5 lower part of axis forming the stem; A upper end of axis 
with scars of male flowers. Pericarp consists of Epi epicarp, Mes mesocarp with 
fibers, and End endocarp or hard shell ; T portion of spermoderm adhering to endo- 
sperm; Alb endosperm surrounding cavity of the nut; A" germinating eye: (Winton.) 

receptacle and ovary wall. If the flower has several ovaries, these on 
ripening form an aggregate fruit. A compound or multiple fruit consists 
of the united fruits of several flowers. The receptacle of aggregate and 
compound fruits is sometimes fleshy, forming the bulk of the fruit. Ex- 
amples are the strawberry, an aggregate fruit with nutlets on the outside 
of a fleshy receptacle, and the fig, a compound fruit with nutlets on the 
inside of a hollow receptacle. 


The mature pericarp may be dehiscent (e.g. legumes, crucifers), or inde- 
hiscent, and in the latter case may be entirely fleshy (e.g. grape, banana, 



and other berries), entirely dry (e.g. acorn and other nuts), or partly 
fleshy and partly dry (e.g. peach and other drupes). It may be distinct 
from the seed or seeds (e.g. peach, legumes), or united with the seed (e.g. 
cocoanut, wheat, and other cereals). 


Fl %nLJ?1Vf • Ba ? be ^ L<W1 " nobilis ^ in cross sectlon - Pericarp or fruit coat 
"a^ &2S3- ^ ^^ and End end0Car ^ * sper^dern, t^r 

Since the pericarp is the ripened pistil and the pistil is a metamorphosed 
leaf, all three are analogous in structure, each consisting of a middle layer 
between two epidermal layers. The mesocarp, or middle layer of fruits 
is often however more complex in structure than the mesophyl of leaves' 


The Epicarp (Figs. 17 and 18, Epi), or epidermis of the pericarp, 
consists of a single layer of cells, often interspersed with hairs and rarely 
with stomata. 

The Mesocarp (Figs. 17 and 18, Mes) in some fruits forms a layer 
several centimeters or even decimeters thick, in others is scarcely thicker 
than a sheet of writing-paper. 

The hypoderm, consisting of one or more layers adjoining the epicarp, 
is often different in structure from the layers further inward. 

The remainder of the mesocarp may be homogeneous throughout 
except for fibro-vascular bundles, or may consist of several forms of cells 
(stone cells, oil cells, etc.) irregularly distributed in a homogeneous 
ground tissue, or arranged in distinct layers. The visible cell-contents 
include starch, sugar, oil, tannin, chlorophyl, calcium oxalate, and other 

The Endocarp (Figs. 17 and 18, End), strictly speaking, consists of the 
innermost cell-layer, but in the case of nuts, dupes, and other fruits the 
hard shell made up of numerous layers of stone cells is commonly desig- 
nated by this term. 


In order to understand the structure of the seed it is essential to con- 
sider the structure of the ovule from which it was developed, and the 
changes this undergoes after fertilization. 

An ovule (Fig. 19) consists of the body or Nucellus (s) in which is 
embedded the Embryo sac (t), the whole being enclosed by one, or more 
often two, coats or Integuments (p, q) with an opening at one end known 
as the Foramen (m). The Chalaza (0) is the base of the ovule where the 
integuments unite with the nucellus : the Hilum is the place of attach- 
ment with the support or Funiculus. In orthotropous and campylotro- 
pous ovules the chalaza is also the hilum, in anatropous and amphitro- 
pous ovules they are more or less separated, and are joined by a ridge 
known as the Raphe («). 

The pollen grains soon after they are deposited on the stigma of the 
flower send off tubes (Mm) which penetrate through the style into the 
cavity of the ovary, and through the foramen into the nucellus, finally 
entering the embryo sac and effecting fertilization. As a result of this 
fertilization the Embryo and the Endosperm are formed in the embryo 
sac, and these together with the Perisperm, consisting of the developed, 
or more commonly, degenerated nucellus, the Spermoderm, consisting of 



the matured integuments, and occasionally certain appendages, make up 

the seed. 

Either the embryo, the endosperm or the perisperm of the mature 

Fig- 19. Flower of Simple Type in Longitudinal Section. 

Stamens consist of c filaments and a, b anthers (a cross section, b after dehiscence show- 
ing pollen grains). 

Pistil consists of h stigma with i pollen grains sending off tubes, one of which (klm) has 
reached and penetrated the ovule, g style, and / ovary, the walls of which later develop into 
the pericarp. 

Ovule consists of it funiculus (below) and raphe (above), chalaxa, p outer integument, 
q inner integument, in micropyle, s nucellus or body of the ovule, and t embryo sac in which, 
through the agency of « antipodal cells, v synergidae, and z oosphere, are developed the 
endosperm and the embryo. 

d bases of sepals; c nectaries. (Sachs.) 

seed may form the chief reservoir of reserve material, or, on the other 
hand may be reduced to a rudiment. 



This reserve material may consist chiefly of starch (e.g. cereals), of oil 
(e.g. cottonseed, linseed), or of cellulose (e.g. coffee, ivory nut). 

A B 

Fig. 20. Cardamom Seeds. A longitudinal section, X 3. B transverse section, X 5. p 
perisperm; e endosperm; em embryo. The reserve material in the perisperm is largely 
starch; in the endosperm and embryo it is oil and proteids. (Luerssen.) 

The Spermodenn, Testa, or Seed Coat, includes all the layers developed 
from the integuments of the ovule. 1 It may be simple or complex, thin or 
thick, soft or hard. In some seeds it con- 
sists of but one or two thin layers (e.g. 
cereals), in others of five or six distinct 
layers, some of the layers being several 
cells thick (e.g. cucurbits). Among the 
common elements are thick- and thin- 
walled palisade cells, stone cells, crystal 
cells, spongy parenchyma, and ordinary 
parenchyma. The "Nutritive Layer" 
found in some seeds is a, parenchymatous 
tissue containing in the early stages of 
development reserve material, but later 
forming an ill-defined, tissue of empty 
compressed cells. 

The hilum, chalaza, and raphe of the 
ovule preserve their characters in the seed, 
while the foramen becomes more or less 
indistinct, forming the Micropyle. 

The raphe (present in anatropous and 
amphitropous seeds) is a bundle of vascu- 
lar elements with more or less distinct 

The appendages of the Spermoderm include the Arillus or seed mantle, 

1 Some authors apply the term "testa'' only to that portion of the seed coat developed 
from the outer integument of the ovule, the portion developed from the inner integument 
(if present) being termed "tegmen." This usage leads to confusion owing to the difficulty 
of tracing the origin of each layer. 

Fig. 21. Linseed in cross section. 
5 spermoderm or seed coat; £ endo- 
sperm; C cotyledons. The reserve 
material, consisting of oil and pro- 
teids, is partly in the endosperm and 
partly in the embryo. (Moeller.) 



an outgrowth from the hilum, the Arillode, an outgrowth from the micro- 
pyle, and the Caruncle, a wart -like body formed on the micropyle, also 

bristles, wings, and other appendages which 
aid in disseminating the seeds. 

The Perispenn or Nucellar Tissue is 
usually a thin layer, often without cell struc- 
ture, but in black pepper and cardamom 
(Fig. 20, p) it forms the larger part of the 
seed and contains the store of reserve starch. 
The Endosperm constitutes the bulk of 
many seeds (e.g. cereals), but is almost 
entirely absent in others (e.g. bean, crucifers). 

Fig. 22. Endosperm of Date 1 

Stone with reserve material in In the cereals the outer layer or layers of 
(MoELLER k ) ened CeU WallS ' the endosperm consist of aleurone cells, the 

remainder, of starch cells; in linseed the 

endosperm (Fig. 21, E), which constitutes about half of the seed, con- 
tains aleurone grains and oil, but no 

starch; in coffee and the date stone 

(Fig. 22) the bulky endosperm contains 

Teserve material in the form of thick- 
ened cell-walls. 

The Embryo is a young plant with 

Cotyledons or seed leaves, Radicle or 

young root, and Plumule or bud. It 

may be embedded in the center or 

one side of the endosperm (e.g. cereals, 

eoffee), or it may constitute the bulk 

of the seed (e.g. legumes, crucifers, 

■cottonseed). In the latter case the 

reserve material, which may be largely 

starch or oil, is located chiefly in 

the thickened cotyledons and radicle 

(Fig- 23). 

Fig. 23. Mustard Seed in cross sec- 
tion. Embryo consists of c folded 
cotyledons and r radicle. Reserve 
material, consisting of oil and pro- 
teids, is entirely in the embryo. 


The stem is the axis connecting the leaf and root systems. It may 
be aerial or subterranean, simple or branched, herbaceous or woody. In 
some herbaceous plants it is exceedingly short, the leaves appearing to 
■spring directly from the root, while in many herbaceous and all woody 


plants it consists of an elongated trunk with or without a system of 

Not only does the stem serve to mechanically support the leaves, but 
also, by means of the bundles, to distribute over the plant solutions of salts 
absorbed by the roots, of carbohydrates assimilated by the leaf, and of 
other organic substances formed in various parts of the plant. During 
the resting season large amounts of reserve material are stored in stems. 


The nbro-vascular bundles of phenogamous stems are collateral, that 
is, the phloem and xylem of each are in the same radial plane. Usually 
the phloem is entirely on the outer side of the xylem, but in some stems it 
is partly on the inner side (bicollateral). 

In the stems of exogenous plants (dicotyledons and gymnosperms) 
the bundles with the parenchyma separating them are arranged in a zone 
between the pith and the cortex. The outer ring of the bundle zone con- 
tains the bast fiber groups, the middle ring, the phloem groups, the inner 
ring, the xylem groups. If the plant is perennial a ring of active cells or 
cambium soon forms between the phloem and xylem rings, adding each 
year new tissues to the inner side of the former and the outer side of the 
latter. The layers outside of the cambium constitute the bark, those 
between the cambium and pith constitute the wood. 

The bundles of endogenous plants (monocotyledons) are irregularly 
distributed through a parenchymatous ground tissue. There is no cam- 
bium and no differentiation into bark and wood. 

The following descriptions of annual and perennial stems apply only 
to exogenous plants: 

Annual Stems. 

The stems of herbaceous plants and the young stems of woody plants 
consist of at least four distinct zones : 

i. Epidermis. This resembles the epidermis of the leaf. Stomata 
and hairs are often present. 

2. Cortex. The tissue is largely parenchyma, often with outer layers 
of collenchyma and inner layers containing either bast fibers or stone cells, 
or both. 

3. Endodermis. This consists of a single layer of cells with thin but 
suberized walls. Starch grains are usually found in the cells. 


All the tissues inside of the endodermis form the central cylinder or 

4. Bundle Zone. The Phloem strand of each bundle consists of sieve 
tubes, cambiform cells, and parenchyma; the Xylem strand, of vessels 
(tracheae), tracheids (distinguished from vessels by the cross partitions), 
and parenchyma. The bundles are separated from each other by paren- 
chyma, developing in perennial stems into the medullary rays. Groups 
of bast fibers are commonly present in the outer parenchyma, or Pericycle. 

5. Pith. This consists entirely of typical parenchyma. 

Perennial (Woody) Stems. 

The structure of perennial stems (Figs. 24 and 25) is much more com- 
plicated than that of annual stems, owing to the formation of secondary 
bark and wood by the cambium, also of cork and secondary cortex by the 

The Bark includes all the outer part of the stem up to the wood. It is 
readily stripped off from the latter, especially during the spring, the separa- 
tion being through the delicate cells of the cambium. Although many 
barks are used in medicine (e.g. cinchona, slippery elm, cascarilla), and 
in the arts (e.g. oak, hemlock), only cinnamon and its substitutes are of 
importance as foods. 

1. Cork. With the increase in diameter of the stem the epidermis is 
ruptured and finally disappears entirely. In its place cork is formed by 
an active (meristematic) layer known as the Phellogen. As the cells of 
the phellogen divide by tangential partitions, the rectangular cork cells, 
as seen in cross sections, are in radial rows. They usually have suberized 
walls, and often contain dark contents with the reactions of tannin. 

As the stems continue to grow the primary cork often suffers the same 
fate as the epidermis, and is replaced by a secondary layer formed in the 
cortex by a new phellogen. This secondary cork may later be replaced 
by a tertiary, and so on. 

2. Secondary Cortex, a thin-walled tissue hardly distinguishable from 
the primary cortex, is formed from the phellogen on the inner side. 

3. Primary Cortex. The parenchymatous ground tissue often contains 
starch and crystals of calcium oxalate. Stone cells and bast fibers may 
also be present. The endodermis of old stems is not usually distinguishable 
from the other layers. 

4. Pencyle, This may consist of parenchymatous ground tissue with. 



isolated groups of bast fibers, or of a "mixed ring" composed chiefly of 
stone cells and bast fibers. 

5. Bast. Like the phellogen, the cambium forms one kind of tissue 
on the outside, another kind on the inside. These are respectively the 
phloem and the xylem, a layer of each being produced each year. The 
phloem layers of different years' growth, together with the separating 

Fig. 24. Branch of the Linden, in cross section, showing the bark and three annual layers 

of wood. (Kny.) 

partitions or medullary rays, form the bast ring. In addition to sieve 
tubes, cambiform cells, and parenchyma, the bast may contain oil cells, 
mucilage cells, latex tubes, and other elements. Starch is often present. 

Microscopic Elements 0} Barks. The elements of chief importance in 
diagnosis are bast fibers, stone cells, starch grains, and cork. The other 
elements have less striking characters. 

Wood. The wood elements, like the phloem elements, are in radial 
rows, separated by medullary rays, and also in annual layers. The ele- 
ments include vessels and tracheids of numerous types, wood fibers, 
parenchyma, and medullary "parenchyma. The parenchyma cells often 

4 2 


contain starch and calcium oxalate, and all the tissues may contain or be 
impregnated with resins, essential oils, etc. 

Woods are not used as foods, but sawdust and red sandalwood powder 
are common adulterants. 

a b c d e f g h i k I m n o 

Fig. 25. Elements of a Dicotyledonous Fibro-vascular Bundle in longitudinal section._ a 
parenchyma of pith; b annular vessel passing into spiral vessel; c spiral vessel; d reticu- 
lated vessel; e wood parenchyma; / wood fiber; g pitted vessel; h wood parenchyma; 
i cambium layer; k cambiform cells; / sieve tubes; m sieve parenchyma; n bast fibers; 
parenchyma. (Kny.) 

The Microscopic Characters of woods of angiosperms and gymnosperms 
as given by Moeller are as follows : 

The Wood of Angiosperms is characterized by the vessels with numerous 
small pits (Fig. 26, g). More abundant than these are the wood fibers 
(/) occurring mostly in bundles, accompanied often by wood parenchyma 
(p), and crossed by medullary parenchyma (m). Simple crystals of calcium 
oxalate in crystal fibers occur in many tropical woods (Fig. 28, k). 

Determination of the species or even the genus by the characters of 
the powder is very difficult. Chief dependence must be placed on the 
structure of the vessels. 

The Wood of Gymnosperms consists in large part of tracheids with 
single rows of bordered pits (Fig. 27, t), which, except in the spring wood, 
where they occur sparingly, are on the sides adjoining the medullary rays.. 
These are most striking in radial sections. Well-formed oxalate crystals 



are absent. The wood of certain European species may be distinguished 
by the_ characters of the medullary rays. 

Fig. 26. Sawdust of an Angiospermous Wood, p wood parenchyma; / wood fibers; 
g vessels with numerous pits; m medullary rays in radial and tangential view; K crystal , 
cells. X160. (Moeller.) 


To this class belong Rhizomes or root-stalks (e.g. ginger), Tubers (e.g. 
potato), and Corms (e.g. cyclamen). Rhizomes in common parlance 

Fig. 27. Sawdust of a Coniferous Wood, t tracheids with single rows of pits; m medul- 
lary rays; p parenchyma. X 160. (Moeller.) 

are classed with roots. Bulbs (e.g. onion) are subterranean stems 
covered with leaf scales. 



Many subterranean stems are reservoirs of starch, sugar, inulm, and 
other reserve materials, and are important foods. Their tissues are much 




Fig. 28. Red Sandalwood {Pterocarpus santalinus), A radial seclion; B tangential sec- 
tion, k crystal fibers; I wood fibers; p wood parenchyma; g bundle; m medullary 
rays. X 160. (Moellee.) 

simpler than those of aerial stems, consisting chiefly of parenchyma with 
a thin covering of cork and relatively few bundles. In the rhizomes of 
dicotyledons the bundles, like those of aerial stems, are collateral ; in those 
of monocotyledons they start as collateral, but later often become con- 
centric, with the xylem encircling the phloem. Mechanical elements, 
being unnecessary, are usually few or entirely lacking. 


The root fixes the plant in the soil and absorbs the water and mineral 
matters essential for life and growth. In certain plants the root is fleshy, 
serving as a storehouse for reserve material. The roots used as foods 
include the turnip, beet, carrot, parsnip, chicory, and others. 

Annual Root. 

The general structure resembles that of dicotyledonous stems, but the 
elements of the epidermis and the arrangement of the bundles are quite 


i. Epidermis. Root hairs, consisting of blunt, thin- walled outgrowths 
from the center of epidermal cells, are found on young roots. Hairs 
such as occur on aerial parts, as well as stomata, are never present. 

2. Cortex. This is a parenchyma tissue similar to that of stems. 
Chlorophyl is absent. 

3. The Endodermis is characterized by the suberized and often 
thickened walls. 

4. Bundle Zone. The outer layer (pericycle or pericambium) is of 
parenchyma. The bundles proper are of the radial type the phloem and 
xylem being side by side, not one in front of the other, as in the collateral 
bundles. The groups of xylem and phloem elements alternating with one 
another form a chain about the center of the root. 

5. Pith. This may or may not be evident. 

Certain fleshy annual roots, such as the beet, show concentric rings 
similar to those of wood. These are formed by a series of new cambium 
layers which appear one after another in the parenchyma, each producing 
a ring of phloem and xylem. 

Perennial (Woody) Roots. 

The secondary changes in the roots of monocotyledons are not impor- 
tant, but in dicotyledons the structure finally becomes much the same as 
that of the stem. The epidermis with root hairs is replaced by cork, and 
the bundles change from radial to collateral. The cambium forms out- 
side of the xylem and inside of the phloem of each bundle, and conse- 
quently is at first sinuous in cross section. As the thickening proceeds the 
radial arrangement disappears, and the cambium finally forms a ring like 
that of stems. 

See p. 27. 



Grain, in the ordinary acceptance of the term, includes such fruits of 
the cereals (Graminece) and buckwheats (Polygonacea) as are valuable as 
food for man and cattle. 

The impurities of grain include weed seeds, ergot, spores of smuts, 
straw, dirt, and other matters (p. 145 et seq.). Weed seeds belonging to 
the Graminece and Polygonacece are described with the economic species 
of these families. 

The nature and purity of grain is -readily determined by macroscopic 
examination, although a thorough understanding of the microscopic 
structure of the whole grain is essential for the diagnosis of products. 

Flour and Meal. 

In s the examination of mill products with respect to their purity and 
wholesomeness, the following points call for consideration: (1) Is added 
mineral matter present? (2) Is it or has it been infested by insects or 
other forms of animal life ? (3) Has the product or the grain from which 
it was made been damaged by rusts, moulds, or bacteria? (4) Was it 
made from sprouted grain? (5) Are starch or tissues of weed seed present 
in appreciable amount ? (6) Are foreign flours or other vegetable adulter- 
ants present? 

Mineral Adulterants. Calcium sulphate (gypsum), calcium carbonate 
(chalk), clay, and even sand were formerly added to flour and meal, but 
at the present time are seldom if ever used in any cereal product, although 
calcium sulphate in considerable amount has been frequently detected in 
cream of tartar and baking-powder, and powdered rock (talc and tremo- 
lite) to the extent of 25 per cent has been found in one brand of baking- 
powder examined at the Connecticut Experiment Station. 

Foreign mineral matter is best detected by determinations of ash, 
supplemented by an ash analysis, although the chloroform test (p. 51) 
furnishes valuable indications. 47 


Insect ana other Animal Contamination. According to Chittenden* 
the insects which most commonly infest grain and flour are cosmopolitan, 
having been distributed by commerce to all quarters of the earth, ihe 
following common species are described: ., ,„ , , 

The granary-weevil (Calandra granaria L.), the rice-weevil K Calandra 
oryza L.), the Angoumois grain-moth (Sitotroga cerealella 01.), the wolf- 
moth [Tinea granella L.), the Mediterranean flour-moth (Ephestia Kueh- 
niella ZelL), the Indian (maize) meal moth (Plodia inter punctella Hbn.), 
the meal snout-moth (Pyralis farinalis L.), the confused flour-beetle 
(Tribolium confusum Duv.), the rust-red flour-beetle {Tribolium jerrugi- 
neum Fab.), the slender-horned flour-beetle (Echocerus maxillosus Fab.), 
the broad-horned flour-beetle (Echocerus cornutus Fab.), the small-eyed 
flour-beetle (Palorus ratzeburgi Wissm.), the yellow meal-worm (Tenebrio 
molitor L.), the dark meal-worm (Tenebrio obscurus L.), the saw-toothed 
grain-beetle (Silvanus surinamensis L.), the red or square-necked grain- 
beetle (Cathartus gemallatus Duv.), the European grain-beetle (Cathartus 
advena Waltl.). and the cadelle (Tenebroides mauritankus L.) 

Among the creatures found only in the ground products are the sugar- 
mite (Lapisma saccharina), the common flour-mite (Acants farina), and 
the feathered mite (Acarus plumiger). 

The figures and descriptions given by Chittenden, Bohmer, 2 and other 
authors aid in the identification of the foregoing species. 

In cases where the live insects are no longer present evidences of 
previous infection are often furnished by the wings or other parts of dead 
insects, also by the excrement, webs and other remains, seen either with 
the naked eye or under the microscope. 

Wheat is often infested by the wheat- worm (Tylcnchus scandensSchu., 
Anguillula tritici Need.) a nematode related to Trichina. So-called 
"cockle -wheat" (Fig. 29) consists of wheat kernels entirely transformed 
by the ravages of this disgusting, but probably harmless, creature. The 
more or less distorted kernels are from 3-7 mm. long, and often forked at 
the apex. The tough shell, consisting of rather thicfc-walled porous 
sclerenchyma elements with intercellular spaces, inclose a tangled mass of 
worms, which, as may be seen with a low power, become active when 
thrown into water.. The worms are upward of 1 mm. long, pointed at 

1 Some insects injurious to stored grain. U. S. Dept. Agr. Farmer's Bulletin No 45. 

Washington, 1896 

2 Kraftfuttermittel, pp. 65-68. 



both ends, and appear to be filled with a granular substance. They are 
easily recognized in water mounts. 

The Cryptogamic Plants which attack the inflorescence of cereals 
often render the grain unfit for flour-making. To this class belong the 
smuts (p. 165) and ergot (p. 164). 

Molds, yeast plants, algae and bacteria are also developed in the flour 
itself, especially after exposure to dampness, and as a consequence the 


Fig. 29. Cockle Wheat. I whole grains somewhat enlarged. II, cross section: 
ep epidermis; p thick-walled parenchyma. (Vogl.) 

flour becomes "off color," lumpy, and offensive both in odor and taste. 
Fungus hyphse, spores and other cryptogamic elements furnish microscopic 
evidence of such contamination. 

Bohmer 1 gives analytical keys and systematic descriptions for the 
identification of these and other microorganisms. 

Sprouted Grain. As a consequence of improper storage, grain some- 
times begins to sprout, and thus loses in a greater or less degree its value 
for flour-making. Under the microscope the starch grains have a char- 
acteristic appearance due to their partial solution by the diastatic ferments 
developed during germination. The concentric rings are unusually dis- 

1 Loc. cit. 



tinct, and branching channels resembling burrows of worms occur in many 
of the grains (Fig. 30). 

Weed Seeds. See pp. i45" l6 3- 

Foreign Flour. In Europe, wheat flour is sometimes adulterated! 
with rye, barley, buckwheat, rice, bean, potato, or acorn flour, while in 
America it is frequently mixed with maize flour. 

Rye flour, in both Europe and America, is much oftener adulterated 
with inferior wheat flour than wheat flour with rye flour. 

Buckwheat flour is often mixed with wheat, maize, barley, or rice 

Fig. 30. Starch Grains from Sprouted Cereals. Left, large grains from wheat; right, 

from rye. (VoGt.) 

flour, sometimes with the intent of cheapening the product; less often to 
meet the demands of consumers. 

Rice flour is liable to the same forms of adulteration as buckwheat 
flour, while maize flour, because of its cheapness, is seldom adulterated. 

Sawdust, Maize Cob, and other similar waste products cannot be 
reduced to a sufficiently fine powder to be used in fine flour, but are some- 
times mixed with coarse meal, and cattle foods. They are detected by 
their high percentage of crude fiber and low percentage of starch and 
protein, as well as by their characteristic tissues. 

Methods of Examination. 

Preliminary Examination. The color, odor, taste, and other physical 
characters should first be noted and compared with samples of known 
purity. Flour or meal that is damp, mouldy, foul-smelling, or infested 
by insects, is obviously unfit for food whatever may be the results of 
chemical or microscopic examination. 

Pekar Color Test. In German mills and custom-houses since 1894, 
the color of flour has been determined by " pekarizing." As carried out 
in American mills this test is as follows } 

1 Vereinbarungen zur einheitlichen Untersuchung u. Beurtheilung von Nahrungs- u. 
Genussmitteln. Berlin, II, 1899, 18. 



Place 10-15 grams of the flour on a rectangular glass plate or smooth 
piece of wood, about 12 cm. long and 8 cm. wide, and pack on one side 
in a straight line by means of a flour trier. Treat the same amount 
of the standard flour used for comparison in the same manner, so that 
the straight edges of the flour are adjacent. Carefully move one of 
the portions so as to be in contact with the other, and " slick " both 
with one stroke of the trier, in such a manner that the thickness of the 
layer diminishes from about 0.5 cm. on the middle of the plate to a thin 
film at the edge, and the line of demarcation between the two flours is 
distinct. Cut off the edges of the layer with the trier, so as to form a 
rectangle, and compare the color of the two flours. 

The difference in color becomes more apparent after carefully im- 
mersing the plate with the flour in water, and still more apparent after 

By this test the color of different samples may be more accurately 
compared than when loose. Since the introduction of bleaching with 
nitrogen peroxide or chlorine the value of the test in judging the grade 
of flour has been much impaired. 

Caillettet's Chloroform Test, designed chiefly to furnish indications of 
mineral adulteration, consists in shaking in a test-tube about 2 grams of 
the flour with 25 cc. of chloroform. If on standing, any considerable 
amount of deposit collects at the bottom of the tube, the presence of 
mineral matter is indicated, as the flour particles, being for the most part 
lighter than chloroform, rise to the surface. 

This residue may be examined chemically, but the test should always 
be corroborated by an accurate determination of ash in the original material 
and an analysis of the ash. 

Beneke's Chloroform Test. 1 This test serves not only to detect mineral 
powders but also to distinguish rye flour from wheat flour, or to detect 
the presence of one in the other. It is as follows : Place 100 grams of 
the flour in a 500-600 cc. flask and add enough chloroform to fill the flask 
two thirds full ; cork and shake carefully until no lumps remain ; . then fill 
nearly full, shake vigorously, and allow to stand. A brown deposit of 
dirt soon settles, and gradually a further deposit, consisting largely of aleu- 
rone cells forms a layer over the last. After about 24 hours, this latter 
deposit should be examined with the naked eye and under the microscope, 
noting especially the color. The aleurone cells of rye are blue or olive- 
green, those of wheat yellow-brown. 

1 Landw. Vers'-Stat., 1889, 36, 337. 

52 GRAIN. 

Vogl's Alcohol-Hydrochloric Acid Test 1 furnishes indications of the 
presence of foreign flour or ground weed seed. 

Shake violently 2 grams of the flour in a test-tube with 10 cc. of a solu- 
tion containing 5 per cent of hydrochloric acid and 70 per cent of alcohol; 
warm finally at a gentle heat and allow to settle. Note the color in reflected 
light of the column of solution, the meniscus, and the deposit. 

Wheat flour entirely free from impurities yields both a colorless solu- 
tion and a colorless deposit, and wheat flour with a small amount of im- 
purity, also common rye, oat, and barley flour, yield a pale yellow or pale 
yellow-red solution. A decided coloration of the solution, particularly at 
the meniscus, indicates a considerable amount of weed seed. 

Cockle (Agrostemma) and darnel (Lolium) color the solution orange- 
yellow; leguminous seeds, rose-red, violet or purple; cow wheat (Melam- 
fyrum), blue-green or green; ergot, flesh-red to blood-red. 

Gluten Test. Make a handful of the flour into a dough with the 
smallest possible amount of water and wash with continual kneading under 
a stream of water. Wheat flour yields by this treatment an elastic mass 
of gluten while the flour of other cereals is gradually but completely 
washed away. 

1 Chemical Examination. Determination of the usual proximate con- 
stituents in the flour often aids in the diagnosis. For example, wheat flour 
is moderately rich in protein but poor in fat, corn flour is somewhat poorer 
than wheat flour in protein but much richer in fat, while buckwheat and 
rice flour are poor in both of these constituents. 

Microscopical Examination. In 1882, the Association of German 
Millers offered a prize of a thousand marks for an essay describing a simple 
process for detecting admixtures in wheat and rye flour. Wittmack won 
this prize, and the motto of his essay was : " Das Mikrosjtop ist der beste 

Not only is it true that the microscope is the most valuable means for 
the examination of flour, but in many cases it is the only means. 

The following methods of preparing the material for examination will 
be found useful: 

Direct Examination. The points of special importance are the size 
and shape of the starch grains, the presence or absence of aggregates, the 
size of the hilum, and the distinctness of the rings. With the aid 
of the key on p. 64 and the descriptions under each cereal identifica- 
tion of the group and often of the particular starch is readily accom- 
1 Die wichtigsten vegetabilischen Nahrungs- u. Genussmittel, p. 24. 


plished. Among the more difficult problems are the distinction of the 
grains of wheat, rye, and barley; of rice, oats, and darnel; and of maize 
and sorghum. 

Polarized light is useful in determining the locations and form of 
the hilum through which the crossed lines seen with crossed Nicols 
always pass. In cereal starches the hilum is central, and in potato and 
various other starches eccentric. The hilum of leguminous starches is 
elongated (see Fig. 572). 

The crossed lines differ greatly in intensity, being scarcely evident 
in wheat, rye, and barley, but distinct in maize, sorghum, rice and many 
other kinds. 

The brilliancy of the starch grains and their crosses when viewed 
with polarized light also aids in detecting them in the presence of fat 
globules and aleurone grains, although the addition of iodine solution 
accomplishes the same end. 

Heating the water mount to boiling or Addition of Alkali (potassium 
or sodium hydroxide) dissolves at once the starch and protein matter 
and thus clears the tissues. Usually, however, this treatment, which 
is so valuable in the case of materials with considerable bran tissues, 
is of less service in the examination of flour than one of the following 
methods for accumulating the bran tissues from a large amount of the 

Schimper's Scum Method. 1 Mix thoroughly 3 grams of the flour 
with 100 cc. of water and heat without further stirring until the boiling- 
point is reached. The scum which rises to the surface contains the 
greater part of the hairs and other bran tissues, and may be transferred 
to a slide and examined, both directly and after treating with chloral 
or alkali. 

Steinbusch's Diastase Method. 2 Make 10 grams of the # flour into 
a paste with 40 cc. of water and add with constant stirring 150 cc. of 
boiling water. Cool to 55°-6o° C. and add 30 cc. of malt extract (pre- 
pared by digesting at room temperature for 3 hours 1 part of freshly 
ground malt and 10 parts of water and filtering) and keep at S5°-6o° 
for 15-30 minutes. Dilute, allow to settle, decant off the liquid, wash 
the residue once or twice by decantation, and finally treat with 1 per cent 
sodium hydroxide. 

1 Schimper, Anleitung zur mikroskopischen Untersuchung der vegetabilischen Nahr- 
ungs- u. Genussmittel. Jena 1900, 17. 
3 Ber. d. deutsch. Chem. Ges. 14, 2449. 


This method is more laborious than the two following methods and 
has no advantage except in the case of delicate tissues. If quantitative 
determinations of starch are made, the residue after the malt digestion 
may be used for microscopic examination. 

Hydrochloric-acid Method. 1 Mix 5 grams of the flour in a casserole 
with 500 cc. water, heat to boiling, add 5 cc. concentrated hydrochloric 
acid and boil for 15 minutes. After allowing to settle, decant off the super- 
natant liquid and mount the deposit of bran elements either in water, 
chloral or dilute alkali. 

The author prefers the following treatment: Mix thoroughly 2 grams 
of the flour with 200 cc. of water and 2 cc. of concentrated sulphuric 
acid, bring to a boil, allow to settle, and carefully decant off the liquid 
from the deposit containing the tissues. Mount in very dilute sodium 
hydroxide solution. 

Lauck's Method 2 is the same as the crude-fiber method (p. 17) 
except that 2.5 per cent sodium hydroxide is used and the solution is 
boiled but 5 minutes. 

The treatment dissolves completely the starch, proteids and fat, thus 
making the tissues very transparent, but it also distorts the hairs by 
swelling the walls, and for that reason is not suited for the detection of 
wheat flour in rye flour, or vice versa. 

Of the processes for accumulating and clearing the tissues, Schimper's 
scum method has the least action on the cell-walls, Steinbusch's diastase 
method somewhat more, the hydrochloric -acid method still more, while 
Lauck's method is most energetic of all. The methods are arranged 
according to the intensity of their action. 

Vogl's Naphthylene-blue Method. 3 Thoroughly mix 2 grams of the 
flour with a small quantity of a solution of 0.1 gram of naphthylene blue 
in a mixture of 100 cc. absolute alcohol and 400 cc. water. Transfer 
to a slide, allow to dry and examine in sassafras oil or some other essen- 
tial oil or else in creosote or guaiacol. After this treatment the pericarp 
coats and contents of the aleurone cells and germ tissues appear bright 
blue or violet-blue, and the walls of the aleurone cells light blue, while 

1 Various modifications of this method have been described by Moeller, Schimper, and 
other authors. 

2 Vereinbarungen zur einheitlichen Untersuchung u. Beurtheilung von Nahrungs- u. 
Genussmitteln. Berlin, Heft II, 1899, 23. 

3 Die wicht. vegetab. Nahr.- u. Genussm. Berlin and Wien, 1899, 17. 

BREAD. 55 

the tissues and contents of the starch cells remain colorless and are ren- 
dered transparent by the mounting medium. 

BamihVs Test {modified by Wintori). 1 This test serves to detect 
wheat flour mixed with rye and other flours. 

Place a very small quantity of the flour (about 1.5 milligrams) on 
a microscopic slide, add a drop of water containing 0.2 gram of water 
soluble eosin in 1000 cc, and mix by means of a cover glass, holding the 
latter in such a manner that it is raised slightly above the slide and taking 
care that none of the flour escapes from beneath it. Finally allow the 
cover glass to rest on the slide and rub it back and forth until the gluten 
collects into rolls. The operation should be carried out on a piece of 
white paper so that the formation of gluten rolls can be noted. 

Wheat flour and other flours containing it yield by this treatment 
a copious amount of gluten which absorbs the eosin with avidity, taking 
on a carmine color. Rye and corn flour yield only a trace of gluten, 
and buckwheat flour no appreciable amount. The preparations are best 
examined with the naked eye, thus gaining an idea of the amount of 
gluten .present. Under the microscope traces of gluten are so magnified 
as to be misleading. 

In case the, flour is coarse, or contains a considerable amount of 
bran elements, as is true of buckwheat flour and low grade wheat flour, 
the test should be made after bolting, as the bran particles and coarse 
lumps interfere with the formation of gluten rolls. 

The test should be supplemented by microscopic examination of the 
untreated flour and also of the tissues accumulated by bringing to a 
boil with very dilute sulphuric acid and allowing to settle as already 

See Bibliography of Wheat. 


Bread, in the broad sense of the word, including biscuit, cakes and 
other cereal oven products, is made either from the flour of one cereal or 
of several cereals. It is raised commonly either with yeast, baking-powder 
(or an equivalent), or eggs. 

The examination of bread is much more difficult than that of flour, 
partly because other vegetable materials are present, and partly because 
the starch grains of the flour are much distorted by baking. 

' l U. S. Dept. Agr., Bur. Cbem., Bui. 122, p. 217. 



The histological elements include the distorted starch grains (Fig. 31), 
more or less bran tissues, and if yeast" was used as the leavening agent, 
cells of the yeast plant. 

Of the methods of examination described under flour, the diastase 
method, the hydrochloric-acid method, and the crude fiber process, are 

5> «7&~'A~~* 

6 &W& 

Fig. 31. Starch Grains from Wheat Bread, u typical forms, little altered; 6 broken and 

swollen forms. (Moeller.) 

also suited for the examination of bread, provided the material is first 
dried and ground to a moderate degree of fineness. 

Chemical examination includes determinations of the usual proximate 
constituents, tests for alum and other baking chemicals, and, in the case 
of highly colored products, tests for artificial color. 

Cattle Foods. 

Mill Products. The mill products of wheat, rye, barley, rice and 
buckwheat, are more commonly consumed by the human family, only 
the by-products being ch%ap enough for cattle foods. Among the most 
important mill products designed especially for cattle, are maize meal, 
ground oats, and provender (a mixture of maize meal and ground oats). 
Of lesser importance are meals made from the chaffy wheats, sorghum, 
millet, and other cereals. These products are much coarser than flour 
designed for human use, and are invariably prepared from the whole 
kernel without separation of the bran or adhering chaff. 

Mill By-products include the offals of flour mills, breakfast-food 
factories and some other industries. Among the most important materials 
are screenings, bran, and middlings, from wheat, rye, barley, maize, buck- 
wheat, and rice, also more or less analogous materials designated by special 


names, such as hominy feed, oat feed, etc. These products, with the excep- 
tion of screenings, which is treated in a separate chapter (pp. 145-163), 
are described under the different cereals. 

All of these materials contain starch grains in their original form. 

By-products from the Manufacture of Starch and Glucose. In 
Europe starch and glucose are made chiefly from wheat or potatoes, in 
the United States almost exclusively from maize. 

In the American factories, whether starch or glucose is the final product, 
the germ is first separated from the remainder of the grain and subjected 
to pressure to remove the oil. The oil-cake is similar to the cake of 
true oil seeds in that it contains no starch, but a high percentage of pro- 
teid and a considerable amount of residual oil. 

Starch is separated mechanically from the remainder of the grain in 
a wet way and is purified for cooking and laundry purposes, or is con- 
verted by acid into glucose. 

The dried residues from the processes are known as gluten meal, 
gluten feed, starch feed, etc. (p. 96). As they are dried at a rather high 
temperature the starch grains are distorted or entirely disorganized. 

Brewery and Distillery By-products include malt sprouts, brewery 
grains and distillery grains. 

Malt sprouts are the worm-like radicles removed from sprouted barley. 
They are quite simple in structure, and contain no starch in any form (p. 86). 

Malt and distilled liquors may be made from any of the cereals. In 
Europe barley, rye and wheat are chiefly employed ; in the United States, 
barley, rye and maize; in Japan, China, and India, rice and to some 
extent sorghum. 

As the starch originally present in the grain is converted successively 
into sugar and alcohol, the residue or "grains" contain no appreciable 
amount of starch. Both wet and dry grains are used for feeding. 

Chaff of oats, barley, rice, and weed seeds, also maize cob and buck- 
wheat hulls, although of little value except for packing or fuel, are used 
for cattle foods, especially when mixed with more valuable material. 

Oat and barley hulls are obtained in the factories where oatmeal and 
pearl barley are made and are ingredients of certain proprietary cattle 
foods containing, in addition to cereal constituents, some concentrated 
food, such as cottonseed meal or linseed meal. 

Rice hulls, maize cob, peanut shells, and coffee hulls, notwithstanding 
their lack of valuable nutrients and their harsh woody structure, are not 
infrequently met with in cattle foods, especially as adulterants of bran. 

58 GRAIN. 

Methods of Examination. 

Preliminary Examination. The material should first be spread out 
on a paper and fragments of a suspicious nature picked out with forceps. 
This search is usually facilitated by separating the material by means of 
a series of sieves into several portions of different degrees of fineness. 
Many times impurities, such as chaff, insect remains, mouse excrement, etc., 
may be identified with the naked eye or under a lens, although more often 
positive identification is not possible without recourse to the microscope. 

In bran the black hulls of cockle or of black bindweed are often present, 
the former being characterized by the rough outer surface, the latter by 
the smooth but dull surface and the regular shape of the larger fragments. 

Foxtail (Selaria) is recognized by the mottled color and the transverse 
wrinkles on the flowering glumes and other weed seeds by the characters 
learned from the descriptions, as well as by comparison with standard 

Rice hulls or chaff, even in quite small pieces, are recognized under a 
lens by their rough surface and straw-yellow color; oat hulls by the smooth 
convex surface; barley hulls by their smooth but ribbed surface; corn- 
cob by the hard fragments of the woody zone and the hard glumes, also 
by the papery thin glumes, often of a red color. 

The bran coats of wheat and rye are rather soft, of a reddish or buff 
color; those of maize tough and horny, either white, yellow or red (rarely 
blue) ; those of oats and rice, thin and delicate, of a brownish-yellow color. 

These are but a few of the macroscopic characters which either furnish 
positive evidence, or serve as a guide for microscopic examinations. The 
eye of the microscopist as well as his senses of taste, smell, and touch soon 
becomes trained to note very slight peculiarities, which often leads him 
to form an opinion before he has looked in his microscope. 

The Chemical Analysis of fodders commonly includes the determina- 
tion of water, ash, protein (NX6J), crude fiber, nitrogen-free extract 
(by difference) and fat. Determinations of starch, sugars, pentosans and 
albuminoid nitrogen are rarely desirable. 

Microscopic Examination. As the cereal products and bv-products 
used for cattle food are for the most part coarsely ground, and contain 
considerable amounts of the bran coats or chaff, their identification is 
usually easier than that of flour and other products consisting largely 
of starchy matter in the form of a fine powder. 

Direct Examination. For the identification of starch grains an ex- 


amination is made in water either of the fine powder separated from 
the coarse by sifting, or of a finely-ground sample of the whole material. 
Coarse fragments of a starchy nature picked out with the forceps are 
crushed, scraped or sectioned and likewise examined in water. Exami- 
nation with the aid of polarizing apparatus is often useful. 

Treatment with Reagents. Fragments of bran or chaff may also be 
examined directly in water, but much better results are secured after 
first dissolving the starch and other interfering substances, either by 
boiling for a moment in water on the slide (always under a cover-glass), 
or by mounting in dilute alkali or in chloral hydrate. 

It is often convenient to examine the finely-ground material or iso- 
lated fragments, first in cold water, then after treatment with a small 
drop of iodine tincture, again after boiling, and still again after treatment 
with a small drop of 5 per cent potash or soda solution. 

Crude-fiber Process. As most cattle foods contain a considerable 
amount of the bran coats and other tissues, there is commonly no need 
of resorting to the methods described under flour, as a means of accumu- 
lating the tissues from a rather large quantity of the material, although 
as a means of clearing the tissues, some of these methods, particularly 
Lauck's method, or what is practically the same thing, the crude-fiber 
process, are occasionally useful. After weighing the fiber a portion 
obtained in the quantitative determination of crude fiber may be used 
for microscopic examination, as the subsequent determination of ash 
in this fiber is not appreciably affected by the removal of the small quan- 
tity necessary for the purpose. 


See General Bibliography, ppl 671-674: Beneke (2); Bohmer (6, 23); Collin et 
Perrot (9). 

Chapman: The Microscopic Identification of Cattle Foods. Mass. Agr. Exp. Sta. 
Bui. 141. 



CEREALS (Graminece). 

Most grasses are hermaphrodite, the organs essential to fertilization 
being in the same blossom, although in some blossoms either the male 
or female element is abortive. Maize is, however, monoecious, the flowers 
of the tassels being entirely male, those of the ear entirely female. 

The inflorescence is in panicles, racemes, or spikes, made up of spike- 
lets (Fig. 32, A), each consisting of two lower scales (empty glumes) on 
opposite sides of the axis, and one or more flowers (B), each usually 
inclosed by two scales, the one (flowering glume) situated on the 
outer side, the other (palet) two-veined and two-keeled, situated on 
the inner side with its back toward the axis. Sometimes the flower is 
inclosed by only one scale, in which case it is the palet that is lacking. 
Two minute hyaline scales (lodicules) are commonly present at the base 
of the flower and rarely a third occurs within the palet. The beard 
of the spikelets consists of coarse bristles, often barbed, which may be 
borne on the glumes or palets, in which case they are known as awns 
(e.g., wheat), or may spring from the base of the spikelet (e.g., Setaria). 
Commonly there are three stamens (rarely one, two, four, or six) with 
slender filaments and versatile anthers. The pistil has a one-celled 
ovary containing a single ovule, and one to three styles with feather- 
like stigmas. The flowering glume and palet, although free at the time 

JhAl Y •? {TrUlcum sat ™»™\- A s P lk elet with four flowers; B single flower; C 
whole fruit or caryopsis; D fruit in longitudinal section. 1 and 2 empty glumes- b 
flowering glumes; v palets; e embryo. (Schumann.) PV g'umes, o 

of flowering, sometimes become closely adherent to the fruit during 
npening (e.g., barley), or so closely envelop it that they are not sepa- 
rated by threshing (e.g., oats). 


In general appearance the cereal grains resemble seeds, but a study of 
their development clearly shows that they are true fruits. Each consists of 
a single fruit leaf with edges rolled over and grown together, the groove on 
the ventral side of wheat and other grains marking the line of juncture. 

The fruit (Fig. 32, D; Fig. 62) consists of the bulky endosperm and the 
small embryo embedded in the endosperm at the base of the grain on the 
dorsal side, the whole being encased by the pericarp and spermoderm. The 
outer cell-layer of endosperm (in barley, two or more of the outer layers) 
contains proteid matters but no starch; the larger part of the endosperm, 
however, is a mass of large cells closely packed with starch grains. In 
the embryo three distinct parts are evident: the plumule, consisting 
of undeveloped leaves, the radicle or rootlet, and attached to these on 
the side adjoining the endosperm, the scutellum (cotyledon), which at 
x the "time of sprouting draws the nutritive matter from the endosperm and 
conveys it to the young plantlet. The embryo contains fat and protein 
but no starch. 

Microscopic Characters of the Cereals. 

The Glumes and Palets have much the same structure as the leaves 
of which they are but modifications, and normally contain four distinct 
tissues : 

1. The Outer Epidermis is made up largely of cells with wavy outline, 
arranged end to end in rows. Usually these wavy cells are strongly 
elongated, and between them are interposed isodiametric cells often 
extended beyond the surface as hairs ("silica cells") and twin cells, one 
of the twins being usually crescent-shaped. 

2. The Hypoderm consists of one or more layers of sclerenchyma 
elements resembling bast fibers. This layer is imperfectly developed or 
entirely absent in the thin glumes and palets. 

3. Spongy Parenchyma, corresponding to the mesophyl of leaves, 
makes up the third layer of variable thickness. In oats these cells are 
star-shaped, but in the other cereals they are more or less rectangular 
in form. 

4. The Inner Epidermis is usually of thin-walled cells with less striking 
characters than the outer epidermis. Hairs are often present. 

The Pericarp differs greatly in the number of layers and the form of 
the cells, but in general consists of four distinct tissues: 

1. The Epicarp of porous cells, with or without hairs at the apex of 
the grain. 

62 GRAIN. 

2. The Hypoderm and Mesocarp, often of porous cells. 

3. The Cross Cells (so named by Wigand), a layer of cells transversely 


4. The Tube Cells (so named by Vogl) or endocarp, consisting of 

detached vermiform cells longitudinally arranged. 

The Spermoderm of thin-walled cells is usually inconspicuous. 

The Perisperm, or nucellar layer, also known as the hyaline layer, 
usually forms a thin coat of one or two layers of colorless, more or less 
obliterated cells, which, with suitable preparation and under favorable 
conditions, may be seen in surface view. In the case of sorghum, the 
layer is conspicuous and of diagnostic value. 

- The Endosperm. 1. The so-called " Aleurone Cells, " or "gluten cells " 
—both misnomers, as they contain neither aleurone grains nor gluten- 
form several layers in barley, but only one layer in other cereals. These 
cells have thick walls, and contain protein matter and fat but no 
starch. 1 

2. The Starch Parenchyma, which makes up the great bulk of the 
fruit, is closely packed with starch grains varying greatly in shape and 
size according to the species. 

Embryo. The cells are small and, like the aleurone cells, contain 
much oil and protein but no starch. 

Analytical Keys to the Cereals and Graminaceous Weed Seeds. 

I. Key Based on the Structure 0} the Thick Glumes and Palets. 

A. Outer epidermis of cells' with wavy side walls, interspersed with circular cells (often 
forming hairs) and twin cells. 

(a) Spongy parenchyma of star-shaped cells. 

1. Circular cells forming conical hairs; saw-edge of hairs on keel of palet. . . Oats. 

(b) Spongy parenchyma of rectangular cells. 

1 The early microscopists, believing that the outer starch-free layer of the endosperm was 
the seat of the gluten of the grain, gave to these cells the name gluten cells. Schenk, how- 
ever, in 1872 showed that gluten, like starch, was present only in the inner endosperm cells, 
and Johannsen in 1883 reached the conclusion that the contents of the so-called gluten cells 
were aleurone grains embedded in fat. During the past twenty years the name aleurone 
cell has been slowly taking the place of the earlier name. v. Hohnel, Berthold, and other 
authors have not only accepted this view, but have used the size of the so-called aleurone 
grains as a means of distinguishing the different cereals, a procedure which has been severely 
criticized by Wittmack, Moeller, and others. 

Recently Brahm and Buchwald have found that the name aleurone cells is quite as erroneous 
as the earlier term, since what appear to be aleurone grains embedded in fat are really fat 
globules in a ground substance of amorphous proteid matter. They state that a more exact 
name would be " protein cells ", or, better still, " starch-free peripheral cells " of the endosperm. 


2. Circular cells and saw-edge of hairs as in oats. 

Spelt, Emmer, One-grained Wheat. 

3. Circular cells as in oats; no saw-edge of hairs on palet Barley. 

4. Circular cells represented by hair scars Sorghum. 

5. Circular cells large and porous; wavy cells often very short Darnel. 

6. Circular cells porous with wavy side walls; wavy cells long Chess. 

B. Outer epidermis of porous and non-porous cells, with thick, but not wavy walls,, 

interspersed with hairs. 

7. Cells on the papery ends with thin wavy walls Maize. 

C. Outer epidermis mostly of one kind of cell with thick deeply sinuous side walls. 
(a) Epidermal cells broader than long, colorless. 

8. Surface rough; spongy parenchyma of rectangular cells Rice. 

(6) Epidermal cells somewhat longer than broad, colorless, or mottled. 

9. Surface smooth, colorless Common Millet. - 

10. Surface with narrow wrinkles, colorless German Millet. 

n. Surface with narrow wrinkles, mottled Green Foxtail. 

12. Surface with 'broader wrinkles, mottled Yellow Foxtail. 

IT. Key Based on the Structure oj the Bran Tissues. 

A. Cross cells elongated polygonal, side by side in rows, forming a continuous layer. 
(a) Side walls of cross cells thick, distinctly beaded. 

1. Hairs less than 1 mm. long with narrow lumen Wheat. 

2. Hairs often over 1 mm. long Spelt- 

(6) Side walls of cross cells indistinctly beaded. 

3. End walls often swollen; hairs with broad lumen Rye- 

4. End walls of cross cells thin (not swollen) Emmer. 

5. Cross cells as in rye, hairs as in wheat One-grained Wheat. 

(c) Walls of cross cells thin, not beaded. 

6. Cross cells in two layers Barley.. 

7. Hairs long, narrow at base Oats. 

8. Fungus layer usually present Darnel. 

B. Cross cells vermiform, forming an interrupted layer. 

9. Epicarp cells transversely elongated; walls non-porous; end walls deeply 
sinuous Rice. 

10. Epicarp and hypoderm with wavy beaded side walls Sorghum. 

I Common Millet, German 
Millet, Green Foxtail, 
Yellow Foxtail. 1 

C. Cross cells forming spongy parenchyma. 

12. Cells with long narrow arms; epicarp and mesocarp of s rongly developed, 

elongated, beaded cells; endosperm thin -walled Maize. 

13. Cells star-shaped or irregular; epicarp not beaded; mesocarp undeveloped^ 

endosperm thick -walled . Chess. 

1 Distinction by tissues of chaff. 

64 GRAIN. 

III. Key Based on the Characters of the Starch Grains. 

A. Large starch grains mostly over 20 n, round with indistinct hilum; feeble crosses 

with polarized light. 

1. Many grains over 50 p Rye. 

2. Few grains over 50 jx Wheat, Spelt, Emmer, One-grained Wheat. 

3. No grains over 50 ft Barley. 

B. Large starch grains mostly over 15 /«, polygonal or round, with distinct hilum. 

4. Distinct crosses with polarized light Maize, Sorghum. 

C. Grains less than 20 ft mostly polygonal, often in round or ellipsoidal aggregates. 

5. Occasionally spindle-shaped grains Oats. 

6. No spindle-shaped grains Rice, DarneL 

D. Grains less than 20 /1, mostly polygonal, never in rounded aggregates. 

(Common Millet, German 
Millet, Green Foxtail, 
Yellow Foxtail. 1 

E. Grains less than 20 p, ellipsoidal. 

8. Hilum elongated, very distinct Chess. 

WHEAT. 65 


Common wheat (Triticum sativum var. vulgare (Vill.) Hackel), the 
most important of the bread cereals, is grown throughout the temperate 
regions of the earth. The numerous cultivated varieties differ greatly 
in habit of growth, hardiness, presence or absence of beards, and also in 
the form, size, and color, of the grain, but they are commonly grouped in 
two classes: the " Winter Wheats, " or those sown in the fall and therefore 
adapted only to the wanner regions, and the "Spring or Summer Wheats," 
including the varieties grown in colder countries. 

The grain of all these cultivated varieties readily separates from the 
chaff on threshing, and is termed "naked wheat" in contradistinction to 
the spelts, which, like barley and oats, are closely invested by the chaff. 

Other species and varieties of wheat yielding naked grains are Polish 
wheat (T. Polonicum L.), English wheat (T. sativum var. turgidum (L.) 
Hackel), macaroni, hard or glass wheat (T. sativum var. durum (Desf.) 
Hackel), and hedgehog, or dwarf wheat (T. sativum var. com pactum 
(Host.) Hackel). 

The grain of common wheat (Fig. 32, C and D) is oval in longitudinal 
section, heart-shaped in transverse section. Other characteristics are the 
slightiy -keeled back with a pronounced depression at the base marking the 
position of the embryo, the deep, longitudinal groove on the ventral side, 
and finally the beard on the end. In color the kernels vary from light 
yellow to brown. Rye kernels are longer, more slender, more pointed 
at the base, and of a darker color. 

The kernels of macaroni and English wheat resemble those of com- 
mon wheat in shape, but are larger. 

Polish wheat is distinguished from all the other wheats by its long 
(often 12 mm.), slender, rye-shaped kernels with a sharp-pointed base. 


As the glumes and palets of all the varieties named remain with the 
straw on threshing, they do not enter into the composition of mill products, 
and their anatomy is for us of no moment. All the naked wheats have 
practically the same structure. 

After soaking the grain for some hours in water cross-sections may 
be cut with a razor or microtome, and surface preparations obtained by 





Fig. 33. Wheat. Cross section through bran coats and outer endosperm of fruit. F peri- 
carp consists of cut cuticle, epi epicarp, hy hypoderm (first layer of mesocarp), Ir cross 
cells and tu, tube cells; S, spermoderm consists of two brown layers; P perispenn; 
E endosperm consists of al aleurone cells and am starch cells. X 160. (Moeller- 

?& i™&f m - SUI t C i V1 T' ep ,i e P lcar P at end of ? rain with t hairs; 
«*' epicarp on body of grain; hy hypoderm (first layer of mesocarpl; *n intermediate 

&S cross f ce " s ; ful ^P^? 1 tul * cells; <« 2 tube ceUs passing Into spongy paren- 
chyma; outer layer and 1 inner layer of spermoderm; P perisperm; afaleurone 
cells; aw starch grains. X160. (Winton.) 

WHEAT. 6 7 

Pericarp (Fig. 33, F). 1. The Epicarp (Fig. 33 , epi, Fig. 35) is 
composed of colorless cells, which, except at the apex of the grain 
(Fig. 34, epi i) are longitudinally elongated and are arranged end to end 
(but not side by side) in rows (epi 2 ). A thin cuticle covers the outer 
wall (Fig. S3, cut )- In surface view, both tne side and end walls appear 
distinctly beaded, the double side walls being about 4^ thick. At the 
apex of the grain the cells are nearly isodiametric, and between them 
arise numerous hairs (Fig. 34, t; Fig. 36) which vary up to 1 mm. in length 
and (measured near the base) up to 25/1 in diameter. Most of them 

Fig. 35. Wheat. Epicarp in surface Fig. 36. Wheat. Hairs from the apex 
view. X300. (Moeller.) of the grain. X300. (Moeller.) 

are awl-shaped, with a more or less globular base, and, as Wittmack 
first noted, a narrow lumen or cell-cavity, the breadth of which is less 
than the thickness of the walls. 

2. The Mesocarp consists of two or three layers of cells, which differ 
little from those of the epicarp. 

3. The Intermediate Layer (Fig. 34, in) occurs here and there be- 
neath the mesocarp, chiefly in the cleft, forming a spongy parenchyma. 
The cells are of fantastic shapes and occur not infrequently in bran and 
low-grade flour. 

4. Cross Cells (Figs. 33 and 34, tr; Fig. 37). Beneath the meso- 
carp is another layer of cells with porous radial walls, but these are trans- 
versely elongated and, as may be seen in surface view, are arranged not 



end to end but side by side in rows. Over the larger part of the surface, 
the cells are 100-200/. long and 15-25 /* broad, but in the region of the 
apex they are shorter and more irregular in form. The very distinctly 
porous, double side walls are about 7 fi thick, but the end and outer 
walls are often much thinner, and the end walls are never swollen as 
in rye. Intercellular spaces sometimes occur at the angles. Treatment 
with alkali imparts a yellow color, but does not appreciably swell the walls. 

This layer, from the diagnostic standpoint, is the most important of 
the bran tissues. 

5. Tube Cells (Figs. 33 and 34, <«)• Instead of an unbroken layer 
of cells, the endocarp of wheat, as of most of the cereals, consists of more 
or less detached vermiform cells arranged parallel to the axis of the 

Fig. 37. Wheat. Surface view of cross cells. X300, (K. B, Winion.) 

grain. Oftentimes two adjoining cells are in interrupted contact, with 
circular intercellular spaces formed by sharp bends in the walls, suggest- 
ing that this layer is but disintegrated spongy parenchyma (lu 2 ). Cross- 
sections of these cells are circular or elliptical. 

Spermoderm (Fig. 33, S; Fig. 34, and i). In cross-section, before 
treatment with reagents, the two layers of the spermoderm appear like 
yellow-brown, structureless membranes, the inner somewhat darker than 
the outer; but on treatment with Javelle water, the cell structure can 
often be recognized. Owing to their brown color, the layers are readily 
found in surface preparations. The thin-walled, elongated, pointed cells 
of the two layers cross one another. 

Perisperm (Figs. 33 and 34, P). The remains of the nucellus or 
body of the ovule, known as the " nucellar layer," and by some authors, 
because of its colorless, almost structureless appearance, as the " hya- 
line layer," can be seen in surface preparations only under the most 
favorable conditions. To differentiate this layer, as well as others of 
the grain, Moeller proceeds as follows : Warm a whole kernel with alkali, 



wash in water containing a drop of acetic acid, remove to a slide a por- 
tion of the inner skin, which may be readily separated after this treat- 
ment, and gently press sidewise with a cover-glass. If zinc chloride 
iodine is now added, both cell layers of the spermoderm are colored 
brown, the perisperm and the remaining coats blue. 

Endosperm. 1. The Aleurone Layer (al) is but one cell layer thick. 
These cells, rectangular in transverse section, rounded polygonal in sur- 
face view, are 25-75 /i in diameter. Viewed in water, the double walls 
are about 7 /1 thick; but on treatment with alkali, they swell consider- 
ably and also take on a yellow color. This layer contains proteins but no 
starch. Often the nucleus 
of the cell is clearly seen, 
especially in surface mounts. 

Fig. 38. Wheat. Surface view of 
aleurone cells. X 300. (Moel- 


Fig. 39. Wheat Starch. X300. (Moeller.) 

2. Starch Parenchyma {am). The large isodiametric, thin-walled 
cells 'contain starch grains (Fig. 39) of two forms: (1) large, lenticular 
grains, mostly 28-40/4 (rarely 5o/<) with indistinct rings and hilum; 
(2) small rounded or polygonal grains, usually less than & ft. The large 
grains lying on edge are more or less elliptical in outline; with polarized 
light indistinct crosses dividing each grain into four equal parts are 
evident (Fig. 572, III). The small grains are detached members of 
aggregates, which are seldom found intact. 

Embryo. Tissues of the embryo show little differentiation. The 
cells are small, seldom exceeding 25 /i. They contain fat and aleurone 
grains, but no starch. Treatment of sections with a mixture of iodine 
green or methyl green and fuchsin stains the cell nucelli green, the aleu- 
rone grains red. In many of the cells the contents is largely nuclear 

70 GRAIN. 


Whole-wheat Products. Roasted Whole Wheat is used as a coffee 
substitute and adulterant. In over-roasted kernels it is often difficult 
to identify the tissues. 

Puffed Wheal is prepared by heating in closed cylinders resembling 
cannons, and finally opening the breech. The kernels, which escape 
with violence, are swollen to several times their natural size. 

Graham Flour is the ground wheat kernel with nothing removed. 

Rolled Wheat, a popular breakfast food, is the wheat kernel rolled 
and sometimes partially cooked, but not ground. 

Shredded Wheat is prepared by shredding the kernel in machines of 
peculiar construction, and cooking. • 

"Force," '"Malta-Vita," "Zest," and numerous proprietary foods, 
consist chiefly of wheat which has not only been cooked, but also sub- 
jected to a malting process, thus converting a portion of the starch into 
maltose and dextrines. They come into the market either granulated 
or flaked. 

These products contain all the histological elements of the wheat kernel; 
but in those which have been cooked, the starch grains are more or less 
distorted. The most characteristic tissues are the cross cells with dis- 
tinctly beaded side walls and thin (never swollen) end walls, and the hairs 
i mm. or less long with lumen thinner than the walls. 

Flour and Other Decorticated Wheat Products. Wheal Flour con- 
sists chiefly of the starchy portion of the grain with fragments of hairs 
which pass endwise through the bolts, and, less frequently, other tis- 
sues. The microscopist should note the size, form and deportment 
with polarized light, of the starch grains, also the characters of the tissues 
accumulated by one of the methods described on pp. 53-S5. 

Rye flour is an occasional adulterant of wheat flour, and inferior 
wheat flour is a common adulterant of rye flour. Rye flour is char- 
acterized by the somewhat larger size of the starch grains, the hairs 
with wide lumen, and the indistinctly beaded cross cells, often with 
swollen ends. In America maize flour has been added to wheat flour. 
Maize starch grains are identified by their size, polygonal form, and 
distinct polarization crosses. 

Of great service in the identification of wheat flour, even in mixtures 
containing as little as 10 per cent, is the test which was devised in 1852 by 
Bamihl, a Prussian custom-house official. A small portion of the flour and 
enough water to form a rather thick paste are thoroughly mixed on a slide 


by rubbing a cover-glass. Wheat flour yields by this treatment 
yellowish, stringy, glutinous masses in considerable amount, whereas rye 
and maize flour yield only a trace and buckwheat flour practically none. 
For further details of the test see p. 55. 

Wheat flour, if made into a dough, and kneaded in a stream of water 
to wash away the starch, finally yields an elastic mass of gluten; other 
kinds of flour are entirely washed away by this treatment and yield no 

Weed seeds and other impurities of flour are discussed on pp. 47-50, 
and methods of examination on pp. 50-55. 

Wheat Bread, Biscuit, and other baker's products contain all the 
elements of flour, but the starch grains are more or less distorted (Fig. 
31). Yeast introduces a certain amount of yeast cells and most baking 
powders introduce a trace of corn starch. 

"Grits," "Cream 0} Wheat," etc., are coarsely ground kernels freed 
from bran, and differ from flour chiefly in mechanical condition. 

By-products. Wheat Bran is an important cattle food, a common 
adulterant, and, after roasting, an ingredient of coffee substitutes. It 
consists largely of the pericarp, spermoderm, and gluten cells, with frag- 
ments of the germ, and considerable adhering starch. The cross cells, 
hairs, and starch grains should be carefully noted. 

Among the accidental impurities of bran are the hulls and other ele- 
ments of various weed seeds. The black hulls of cockle are distinguished 
from those of black bindweed by their rough surface as well as by the 
characteristic tissues. Other weed seeds of wheat are considered on 
pp. 145-148. 

In bran adulterated with ground corn-cob, hard lumps of the woody 
zone, and hard glumes may be found under the dissecting lens, or by 
chewing the bran. These, as well as the white or red membraneous 
chaff, may be identified by the methods described on p. 96. 

Corn Bran, a common adulterant, is identified by the thick pericarp. 
Broom-corn waste, coffee hulls, peanut shells, and some other adulterants 
may also be detected by their microscopic characters. 

Wheat Middlings is a term used to describe various products inter- 
mediate between flour and bran, some being chiefly starch matter, others 
bran finely ground. 

Wheat Germs, separated from the flour and bran in the flour mills, 
are used both as a human food ("Fould's Wheat Germ") and as a cattle 
food. They are much smaller in size than those of maize, the only other 

72 GRAIN. 

cereal from which the germs are removed on a commercial scale; but 
when finely ground cannot be readily distinguished from them. 

Wheat Gluten, a by-product from the manufacture of starch, contains 
over 80 per cent of protein and less than 10 per cent of starch. It is a 
valuable diabetic food. Under the microscope the flakes of gluten show 
their amorphous structure. 


See General Bibliography, pp. 671-674: Berg (3); Blyth (5); Bohmer (6, 23);. 
Hanausek, T. F. (16, 17); Harz (18); Hassall (18); Leach (25); Mace - (26); 
Meyer, A. (27); Moeller (29, 32); Planchon et Collin (34); Schimper (37); Tschirch 
u. Oesterle (40); Villiers et Collin (42); Vogl (43, 45); Wittmack (10). 

Baixand: Sur la falsification des farines avec le seigle, le sarrassin, le riz, 1'orge, le 

ma'is, les feres et la fecule de pomme de terre. Jour, pharm. chim. 1899, 9, 239, 286. 
Bamihl: Pogg. Ann. 1852, 161. 

Barnstein: Roggen und Weizen. Landw. Vers.-Stat. 1902, 56, 25. 
Baumann: Nachweis von Maisstarke im Weizenmehl. Ztschr. Unters. Nahr.-Genussm. 

1899, 2, 27. 
Benecke: Zum Nachweise der Mahlprodukte des Roggens in den Mahlprodukten des 

Weizens. Landw. Vers.-Stat. 1889, 36, 337. 
Berthold: Ueber den mikroskopischen Nachweis des Weizenmehles im Roggenmehle. 

Ztschr. f. landw. Gewerbe. Beilage, 1883. 
Bessey: The Structure of the Wheat Grain. Bull. Neb. Agr. Exp. Sta. 1894, 32. 
Brahm und Buchwald: Botanische und chemische Untersuchungen an prahistorischen- 

Getreidekornern aus alten Graberfunden. Ztschr. Unters. Nahr.-Genussm. 1904, 

7, 12. 
Collin: Examen microscopique des farines de ble". Jour, pharm. chim. 1898, 8, 97,. 

150, 200. 
Danckwortt: Ueber Mehluntersuchungen (Bamihl'sche Probe). Arch. Pharm. 187 1, 

145, 47.'' 
Haberlandt: Wissensch.-prakt. Untersuch. auf d. Geb. des Pflanzenbaues. 1, 162. 
Hanausek, T. F.: Zur mikroskopischen Unterscheidung des Weizen- und Roggen- 

mehles. Ztschr. allg. osterr. Apoth.-Ver. 1887, 25, 143. 
Hanausek, T. F.: Ueber die Untersuchung der Mehle. Oesterr. Chem.-Ztg. 1899, 

2, 103. 
Hanausek, T. F.: Ueber die Griffigkeit der Mehle. Oesterr. Chem.-Ztg. 1900, 3, 54. 
v. Hohnel: Die Starke und die Mahlprodukte. Kassel und Berlin, 1882. 
Johannsen: Studien iiber die Kleberzellen der Getreidearten. Bot. Centralbl. 1883, 

15, 305. 
Jumelle: Sur le constitution du fruit des Gramin&s. Comp. rend. 1888, 107, 285. 
Kleeberg: Ueber einen einfachen Nachweis von Weizenmehl im Roggenmehl. Chem.- 
Ztg. 1892, 1071. 
Kornicker und Werner: Handbuch des Getreidebaues. Berlin, 1885. 
Kraemer: An Examination of Commercial Flour. Jour. Am. Chem. Soc. 1899, 21, 650. 
Krasser: Mikroskopische Prufung des Grieses. Ztschr. allg. osterr. Apoth.-Ver. 

r897. 35, 543. 



Krutizky: On Some Peculiarities in the Structure of the Caryopsis of Wheat. 

Uebers. Leist. Gebiet. Bot., in Russland wahrend 1891, St. Peters'g, 1893, 62 ; 

also in Just's Bot. Jahresb. 1893, 21, 1 Abth. 571. 
Kudelka: Ueber die Entwicklung und den Bau der Frucht- und Samenhaut unserer 

Cerealien. Dissertation, Berlin, 1875. 
Lange: Die Mikroskopische Untersuchung von Mehl. Ztschr. angew. Mikrosk. 1896, 

Lebbin: Arch. Hyg. 28, 212. 

Le Roy: Zum Nachweis von Sagespanen im Mehl. Chem. Ztg. 1898, 31; 1899, 264. 
Maurizio: Kleberverteilung im Getreidekorn. Landw. Vers. -Stat. 1902, 57, 405. 
Matirizio : Getreide, Mehl und Brot. Berlin, 1903. 

Moeller: Die Mikroskopie der Cerealien. Pharm. Centralh. 1884, 25, 507. 
Nevinny: Ueber Verunreinigung von Mehlen. Ztschr. Nahr.-Unters. Hyg. 1887, 1, 

2°5. 244- 
Schlickum: Morphologischer und anatomischer Vergleich der Kotyledonen und ersten 

Laubblatter der Keimpflanzen der Monokotylen. Dissertation, Marburg, 1895. 
Spaeth: Nachweis des Mutterkorns im Mehl. Pharm. Centralh. N. F. 1896, 17, 542. 
Stutzer: Nahrungs- und Genussmittel. Handbuch d. Hyg. 3, 243. 
Tardien: Eichelmehl enthaltendes Weizenmehl. Ann. chim. analyt. 1898, 3, 307. 
Vaudin: Sur un element d'erreur dans la recherche du riz ajoute a la farine de froment. 

Jour, pharm. chim. 1899, 9, 431. 
Vinassa: Ueber mikroskopische Mehluntersuchung. Ztschr. Nahr.-Unters. Hyg. 

1895, 9, 53. 
Vogl: Die gegenwartig am haufigsten vorkommenden Verfalschungen und Verunreini- 

gungen des Mehles, etc. Wien, 1880. 
Waage: Zur Unterscheidung von Weizen- und Roggenmehl. Apoth.-Ztg. 1892, 7, 

Weinwurm: Ueber die Verteilung der einzelnen Bestandteile des Roggen- und Weizen- 

kornes auf die verschiedenen Mahlprodukte. Oesterr.-ungar. Ztschr. Zuckerind. 

1890, 19, 163. 
Weinwurm: Ueber eine qualitative und quantitative Bestimmung von Weizenmehl 

im Roggenmehl. Ztschr. Unters. Nahr.- u. Genussm. 1898, 1, 98, 
Wittmack: Sitzgsber. des bot. Ver. f. d. Prov. Brandenburg, 1882, 4. 
Wittmack: Anleitung zur Erkennung organischer und unorganischer Beimengungen 

im Roggen- und Wiezenmehle. Leipzig, 1884. 
Woy: Vorbereitung von Mehlproben zur mikroskopischen Untersuchung. Ztschr. 

offentl. Chem. 1900, 6, 213. 
Anon: Kartoffelfaser als Falschungsmittel fur Kleie. Pharm. Centralh. 1896, 181. 


The three so-called "chaffy wheats," spelt, emmer, and one-grained 
wheat, differ from the common varieties in that the threshed grain, like 
oats, is closely invested by the chaff. 

In ancient times spelt (T. sativum Spelta (L.) Hackel) was one of the 

74 GRAIN. 

leading cereals of Egypt, Greece, and Rome, but at the present time is 
of comparatively little importance. Its culture is limited chiefly to 
Southern Germany (particularly Wurtemberg), Switzerland, and Spain, 
and is slowly giving place to more valuable cereals. 

Each of the more or less four-sided, loosely arranged spikelets con- 
sists of two truncate empty glumes clasping two to three flowers. The 
flowering glumes are thin, many-nerved, awned or awnless; the palets 
are still thinner, two-keeled. Some varieties have smooth, others hairy 
chaff. The grain is triangular with a dense beard. On threshing, the 
axis breaks at the joints and remains attached to the. chaffy spikelets. 


The Empty Glumes are thick, and of horny texture, except on the 
very edges, where they are membranous. 

i.- Outer Epidermis. As is true of most chaffy envelopes of cereals, 
the outer epidermis consists of elongated cells with wavy walls, "twin 
cells", one of which is more or less crescent-shaped, and circular cells, 
the latter often being extended beyond the surface in the form of hairs. 
Except on the edges, the cell-walls are thickened. Stomata occur in 
rows along the nerves. 

2. Hypoderm. Several rows of thick-walled fibers are present ex- 
cept on the edges. 

3. Spongy Parenchyma occasionally is present beneath the nerves, 
but does not form a continuous layer. 

4. The Inner Epidermis is much like the outer epidermis, with thick 
wavy-walled, elongated cells, twin cells, circular cells, and stomata. 

The Flowering Glume is thinner than the empty glumes. 

1. The Outer Epidermis is practically the same as that of the empty 

2. The Hypoderm Fibers are thin-walled and form only a thin layer. 

3. Spongy Parenchyma. Rectangular spongy parenchyma cells form 
a continuous and well-developed layer in the central part of the glume, 
but are lacking on the edges. 

4. Inner Epidermis. The cells are elongated polygonal and have very 
thin walls, which are usually straight, but near the nerves are often wavy. 
Awl-shaped hairs with swollen bases are numerous, especially toward the 

Palets. 1. The Outer Epidermis is practically the same as in the 
other envelopes. Thick-walled, tooth-like hairs, up to 200 ,« in length, 


form a saw-edge on each of the two keels, much like those found on the 
palet keels of oats. 

2. Hypoderm Fibers with thin walls occur throughout, except at the 
very edges. 

3. Spongy Parenchyma is found only under the keels. 

4. Inner Epidermis. Thin-walled, elongated polygonal cells, and 
short, awl-shaped hairs with globular bases form the inner layer. 

Pericarp. The cells of the Epicarp and Mesocarp have thinner walls 
than those of wheat. Spelt hairs are considerably longer than wheat 
hairs, often reaching 1 500 fi ; the breadth of the lumen in some of them 
exceeds the thickness of the walls. The cross cells of wheat and spelt 
are very «imilar, though in the latter the walls are often not so thick nor 
so distinctly beaded. Tube cells occur in considerable numbers. The 
remaining layers are practically as described under wheat; the large 
starch grains, however, are somewhat smaller. 


The products of spelt are grits, other coarse human foods, and fodders. 

Spelt chaff is distinguished from oat chaff by the rectangular cells 
of the spongy parenchyma. Rows of tooth-like hairs form a saw- 
edge on the palet keels of both spelt and oats but not of barley. Hairs 
1000-1500 fi long, such as occur on the epicarp of spelt, are seldom 
or never found in wheat. The cross cells and starch cannot be dis- 
tinguished with certainty from the same elements of wheat. 


Hauptfleish: Die Spelzweizen. Landw. Vers.-Stat. 1903, 58, 65. 

Netolitzky: Mikroskopische Untersuchung ganzlich verkohlter vorgeschichtlicher 

Nahrungsmittel aus Tirol. Ztschr. Unters. Nahr.-Genussm. 1900, 3, 401. 
Vogl: Die wichtigsten vegetabilischen Nahrungs- und Genussmittel. Berlin u. 

Wien, 1899, 75. 


Two-grained, chaffy wheat, or emmer (Triticum sativum var. dicoccum 
(Schrank) Hackel), a cereal cultivated since prehistoric times, is now 
. of little importance, its culture being limited chiefly to sections of South 
Germany, Switzerland, Spain, Servia, and Italy. 

The flattened, often hairy spikelets are densely crowded in the spike. 

76 GRAIN. 

Both of the empty glumes are strongly keeled and narrow gradually to 
the blunt-pointed apex, the keel being prolonged into a short tooth. 


The glumes and palets agree closely in structure with those of spelt, 
and the same is usually true of the pericarp, except as regards the cross 
cells. These latter are thin-walled and, as was rightly noted by Haupt- 
fleisch, are even less distinctly beaded than the cross cells of rye. They 
are distinguished from the latter by the thin (not swollen) end walls. 
According to Hauptfleisch, the epicarp hairs of some varieties have broad 
lumens like rye hairs, but this distinction does not hold good for all 
varieties and cannot be depended on in diagnosis. The statch grains 
are slightly smaller than in common wheat. 

See Spelt, p. 75 


So distinct are the macroscopic characters of one-grained wheat 
from the preceding varieties that it is classed as a separated species 
(T. monococcum L.). Only one fertile flower is present in each spikelet, 
hence the German name Einkorn and the Latin and English names 
above given. 

The empty glumes are rather thin, and have the nerve of the keel and 
the two side nerves continued as short teeth. Both the flowering glume 
and palet are membranous, the latter, on ripening, splitting longitudi- 
nally into two pieces. 


The glumes and palets have the same general structure as the cor- 
responding parts of spelt, but the layers are not so robustly developed. 
Hauptfleisch has correctly observed that the awl-shaped hairs of the inner 
epidermis of the flowering glume are shorter than those of either spelt 
or emmer. In this layer the cell-walls, especially over the nerves, are 
often wavy. The epicarp hairs of one-grained and common wheat are 
not distinguishable, but the cross cells in the former are thin-walled and 
indistinctly beaded much as in emmer and rye. 

See Spelt, p. 75. 




Rye (Secale cereale L.) is botanically closely related to wheat and 
ranks next to it in importance as a bread cereal. 

The naked kernels are longer, more slender, sharper keeled, sharper 
pointed at the base and darker colored than those of wheat; they are 
also not so plump nor so uniform in form, size, and color. 


The rye kernel is in general structure the same as the wheat kernel, 
but some of the layers show differences in detail which are of great im- 
portance in diagnosis. Treatment of sections with cold alkali or chloral 
hydrate swells the walls of the epicarp, middle layer, and perisperm, 
and aids in differentiating them. 

Pericarp (Fig. 40). 1. The Epicarp is distinguished from the cor- 
responding layer of wheat by the thinner and less distinctly beaded walls 
of the cells, and the thinner walls and broader lumens of the hairs (h). 
In both grains the epicarp cells are longitudinally elongated except at 
the apex, where they are more or less isodiametric. Often, but not al- 
ways, the lumen breadth of rye hairs is greater than the wall thick- 
ness. Even at the apex of such hairs the lumen is distinct, whereas in 
wheat hairs it is reduced to a faint line. 

2. The Mesocarp or Middle Layer is only one cell layer thick, and 
the walls are thinner than in wheat, and less distinctly beaded. 

3. Cross Cells (qu). As in wheat, these cells cross those of the outer 
layers at right angles, and are further distinguished by the fact that they 
do not "break joints," but are arranged side by side in rows. They 
are 200 ft or less long and 15-35 n wide. The side walls are thinner 
and less distinctly poi»us than in wheat; furthermore, the end walls 
are often rounded and swollen, with pronounced intercellular spaces, 
whereas in wheat they are thinner than the side walls and without spaces. 

4. The Tube Cells are not numerous. 

The Spermoderm and Perisperm of wheat and rye are hardly dis- 
s tinguishable. 

Endosperm. 1. The Aleurone Cells, according to Vogl, are smaller 
and thicker-walled than in wheat. Moeller notes that on treatment 
with alkali the cell-walls swell greatly (Figs. 41 and 42). 

2. The Starch Parenchyma contains starch grains (Fig. 43) of the 



wheat type, but larger, a considerable number being over 50 ft. They 
often display delicate concentric rings, also fissures radiating from the 


Flo. 40. Rye {Secale cereale). Outer bran layers in surface view. Epicarp consists of 
porous cells, h hairs and * hair scars; qu cross cells. X300. (Moeller.) 

hilum. The small grains are round or angular, seldom in aggregates. 


Whole Rye Products. Roasted Whole Rye is a coffee substitute and 



Rye Graham Flour. The ground whole kernel is used for coarse thread. 
Starch grains (Fig. 43), cross cells (Fig. 40, gu), and hairs (h) are the 
important elements. 

Rye Flour prepared by the usual bolting process is not so white noi 
so fine as wheat and usually contains more bran elements. The dough 

FlG. 41. Rye. Aleurone cells in water. 


Fig. 42. Rye. Aleurone cells 
warmed in alkali. (Moeller.) 

gradually washes away on repeated kneading under running water. 
The large starch grains (larger than in wheat) often with radiating fis- 
sures (Fig. 43), the hairs (Fig. 40, h) with lumen breadth often greater 
than the wall thickness, and especially fragments of cross cells (qu) are 

Fig. 43. Rye Starch. X300. (Moeller.) 

of value in identification. Adulteration with wheat flour is detected by 
the Bamihl test (p. 55) and microscopic examination of the tissues that 
settle after heating to boiling with dilute acid (p. 54). 

By-products. Rye Bran and Rye Middlings, well-known cattle foods, 
contain the coats of the grain and also more or less starch. The side 

80 GRAIN. 

wal^of the epicarp, mesocarp, and especially the cross cells (Fig. 4°> ?«) 
are thinner and less distinctly beaded than in wheat. Some (but not 
all) the cross cells have swollen end walls. 


See Bibliography of Wheat, p. 72—73. 
Egger: Ueber das Vorkommen blaugefarbten Zellinhaltes in der Kleberschicht von 

Roggenkornern. Arch. Hyg. 1883, 1, 143- 
Gregory: Die Membranverdickungen der sogenannten Querzellen in der Fruchtwand 

des Roggens. Beitrage z. wissensch. Bot. 2, 165. 
Hanausek, T. F.: Zur Mikroskopie des von der Presshefe abgepressten Roggenmehles. 

Ztschr. allg. osterr. Apoth.-Ver. 1894, 32, 416. 


Barley (Hordeum sativum L.), one of the most ancient of the cereals, 
is still cultivated in the northern countries of the Old World as a bread 
grain, and throughout the temperate zone for the production of malt. 

The spikes consist of groups of three one-flowered spikelets arranged 
alternately on opposite sides of the zigzag rachis. In six-rowed barley 
(H. sativum var. hexastichon (L.) Hackel) and four-rowed barley (H. 
sativum var. vulgare (L.) Hackel) all of the flowers are fertile. In the 
former variety they form six equidistant, longitudinal rows, whereas 
in the latter only the middle flowers are arranged in distinct rows, alter- 
nating with two more or less indistinct rows formed by the side flowers. 
Only the middle flowers of two-rowed barley (H. sativum var. dislichon 
(L.) Hackel) are perfect, the side flowers being staminate or neuter and 
much reduced in size. The grain of six-rowed and four-rowed barley 
and of many two-rowed varieties is so closely adherent to the flowering 
glume and palet that it is not freed from them by threshing, but the grain 
of some of the two-rowed barleys is naked or hulless. 

Characteristic of the flowering glume are the five prominent ribs, 
the middle one being extended into a long awn, which, however, breaks 
off in threshing. The palet is grooved to correspond with the groove 
in the caryopsis, and is partially hidden from view by the overlapping 
glume. Both before and after the removal of the chaff, the grain is 
distinctly spindle-shaped. The groove on the ventral side of the cary- 
opsis and the depression over the embryo at the base of the dorsal side 
are the same as in wheat and rye. 




Cross-sections are prepared without removal of the glume and palet. 
Successive treatments of the section with potash, dilute acetic acid, and 
chlorzinc iodine solution, or Javelle water and safranin, aids greatly in 
differentiating the layers. The glume and palet are readily separated 
after boiling with water. The layers of these, as well as of the caryopsis, 
are obtained for study by scraping, and may be cleared and stained in 
the same manner as the cross sections. 

The kernels of naked barleys are distinguished from the other varie- 
ties not only by the absence of chaff but also by their larger size and the 
thicker walls of the epicarp and middle layer. 

Fig. 44. Barley (Hordeum sativum). Cross 
section of palet and outer layers of fruit. 
P palet; FS pericarp and s-permoderm; 
endosperm consists of al aleurone cells, 
and E starch cells. X160. (Moeller.) 

Fig. 45. Barley. Palet in surface view. 
Outer epidermis consists of elongated wavy 
cells, h circular cells extended into short 
hairs, and 5 twin cells; / hypoderm fibers. 
X 300. (Moeller.) 

The Flowering Glume and Palet (Figs. 44, -P) are each made up 
of four layers. 

1. The Epidermal Cells (Fig. 45) are strongly silicined and are of 
three forms. First, elongated cells with wavy side walls; second, small 
circular cells extended beyond the surface in the form of conical hairs 
(h); and third, crescent-shaped, hemi-elliptical or circular cells occur- 



ring usually in pairs (5). Examined in water, the thickened, convoluted 
double walls of the long cells appear to be of uniform structure; but on 
treatment with alkali, the zigzag middle lamella separating adjoining 
cells is clearly evident. 

2. Hypoderm (Fig. 44; Fig. 45, /). One to three layers of fibers with 
thick, porous walls, underlie the epidermis. 

3. Spongy Parenchyma (Fig. 44; Fig. 46, p). This layer consists of 
thin-walled, rectangular cells, either isodiametric or slightly elongated 
with numerous circular, elliptical or irregular intercellular spaces. 

Pig. 46. Barley. Surface view of p spongy paren- 
chyma of palet, ep inner epidermis of palet, 
and / epicarp. X 300. (Moeixer.) 

Fig. 47. Barley. Outer epidermis 
with hairs from margin of palet. 

4. Inner Epidermis (Figs. 44 and 48). Cross sections show this 
layer indistinctly; surface preparations, however, bring out the thin- 
walled, elongated epidermal cells, stomata, and rather short, thin-walled, 
awl-shaped hairs, often with swollen bases. 

Pericarp (Fig. 44). Little detail can be made out in cross sections 
mounted in water, but all the layers are evident on treatment succes- 
sively with potash, dilute acetic acid and chlorzinc iodine. 

1. Epicarp (Fig. 49). The cells have rather thin, porous walls. 
On the body of the grain they are longitudinally elongated; at the apex 
more nearly isodiametric. Vogl notes the occurrence of stomata. The 
numerous hairs which clothe the apex are less than 150 ft long. Some 

... > 



like wheat hairs, have walls thicker than the lumen, others, like rye hairs, 
have lumen thicker than the walls. Usually they are broadened at the 

Fig. 48. Barley. Inner epidermis with h 
hairs and st stomata, from middle of 
palet. X300. (Moeller.) 

Fig. 49. Barley. Epicarp with hairs. 

2. Mesocarp. Several rows of cells, similar to those of the epicarp, 
make up this layer. 

3. Cross Cells (Fig. 50, qu). Two rows of cross cells with non-porous 
walls scarcely 2 /i thick, are found in barley. Most of the cells are 
60-100 n long and 10-25 /* wide, but in some parts they are nearly iso- 
diametric. In both layers intercellular spaces frequently occur at the 
angles, and to some extent between the side walls. 

4. Tube Cells (Fig. 50, sch) are not numerous. 

The Spermoderm consists of two . layers of elongated cells, but in 
both layers the cells are longitudinally extended, not crossed as in wheat 
and rye. 

1. The Outer Layer (Fig. 50, ie) is composed of thin-walled cells, 
which can be clearly seen only after treatment with reagents. Chlor- 
zinc iodine brings out the bright yellow cuticle. 

2. The' Inner Layer is composed of thick-walled cells. Treatment 
with potash greatly swells the walls, and subsequent addition of chlor- 

s 4 


zinc iodine colors the swollen walls blue and the cuticle on the inner wall 
bright yellow, but does not affect the middle lamella. 

The Perisperm is often evident in section after soaking in dilute 
alkali, but is rarely seen in surface view. 

Endosperm (Fig. 44). 1. The, Aleurone Layer (al) differs from that 
of ah other cereals in that it is two to four cell-rows thick. In cross 
section the cells are square or radially extended, but in surface view, 

Fig. 50. Barley. Surface view of qu double layer 
of cross cells, sch tube-cells, and ie spermoderm. 
X 300. (Moeller.) 

Fig. 51. Malt Sprouts. Epi- 
dermis with root hairs. 

rounded polygonal, 18-30 ,1 in diameter, with double walls 4 u or more 

2. Starch Parenchyma (E). Barley starch (Fig. 52) occurs in both 
large and small grains resembling closely those of wheat and rye, though 
smaller. The large, circular- or irregularly-shaped grains are commonly 
20-30 p. in diameter and seldom exceed 35 [i. As aggregates are uncom- 
mon, the smaller grains are for the most part rounded and have few if 
any angles. Concentric rings and hilum are often evident. 


Whole Barley Products. Malt, the most important barley product, 
is prepared by first sprouting the grain, thus converting the starch into 
maltose through the action of the diastase ferment. As soon as this con- 



Version is complete, the action of the diastase is stopped by heating, and 
the radicles, known as "malt sprouts," removed. Malt contains all 
the cellular elements of the grain but the radicles. 

Roasted Barley and roasted malt are common coffee substitutes and 

Decorticated Products. Barley Flour is prepared for bread-making 
in some countries, and finer grades are. used as food for infants and in- 

Pearl Barley consists of the kernels denuded of the chaff and bran 
coats, and rounded. Tissues of the pericarp and spermoderm are found 
in the groove. 

Barley Farina or grits is a decorticated product in a coarse granular 

The characteristic elements of the decorticated products are the 
starch granules (Fig. 52), which are smaller than those of wheat or rye, 

Fig. 52. Barley Starch. X 3°°- (Moeller.) 

the thick- and thin-walled hairs (Fig. 49), and occasional fragments of 
cross cells (Fig. 50, qu). 

By-products. Brewers' Grains is the moist residue after extracting 
the sugars and other soluble materials from malt. Both wet and dry 
brewers' grains, also malt sprouts, are utilized as cattle foods. The glumes 
are distinguished macroscopically from oat glumes by the prominent 
ridges, and microscopically by the rectangular cells of the spongy paren- 
chyma (Fig. 46, p). The thin- walled hairs of the inner epidermis (Fig. 
48), the two layers of thin-walled cross cells (Fig. 50, qu), and the two 
or more layers of aleurone cells, further aid in diagnosis. 

86 GRAIN. 

Malt Spouts axe. the vermiform radicles removed in preparing malt. 
Dried sprouts are used as a food for cattle. 

The central cylinder, consisting of incipient vascular elements, ap- 
pears darker than the outer parenchyma zone. Numerous typical root 
hairs arise from the centers of epidermal cells (Fig. 51). 

Other Cattle Foods containing chaff, bran, germs and starchy matter 
are obtained in the manufacture of pearl barley, barley grits, etc. 


See General Bibliography, pp. 671-674: Berg (3); Bohmer (6, 23); Hanausek, T. F. 
(10, 16, 17); Harz (18); Hassall (19); Leach (25); Mace (26); Moeller (29, 32); 
Planchon et Collin (34); Schimper (37); Tschirch u. Oesterle (40); Villiers et Collin 
(42); Vogl (43, 45); Wittmack (10). 

Also see Bibliography of Wheat, pp. 72-73. 
Emmerling: Ueber eine einfache Unterscheidungsweise von Gersten- und Haferspelzen. 

Landw. Vers.-Stat. 1898, 50, 1. 
Holzner: Die Bestandteile und Gewebeformen des bespelzten Gerstenkornes. Ztschr. 

gesamm. Brauwesen. 1888, 473. 
Zoebl: Der anatomische Bau der Fruchtschale der Gerste (Hordeum dislichum L.). 

Verhandl. Naturf. Ver. Brunn. 1889, 27, 1. 
Zoebl: Beitrage zur Entwickelung des Gerstenkornes. Allg. Ztschr. f. Bierbrauerei u. 

Malzfabrikation. 1889. 


The fruit of maize or Indian corn (Zea Mays L.), a plant of American 
origin, is the leading cereal crop of the United States, the production 
being four times as great as that of wheat, and is also a valuable grain 
in Southern Europe. 

By far the larger part of the grain is used as food for cattle, swine, 
and poultry, though a considerable amount is consumed by the human 
family in the form of corn-bread, mush, hominy, and various corn-starch 

The varieties of maize cultivated in America are usually divided 
into five classes, viz.: dent corn (long kernels with a depression in the 
end), flint corn (kernels more nearly round, at the end smooth and con- 
vex), pop-corn (small kernels used for parching or "popping"), sweet 
corn (cooked green as a vegetable), and the less important soft corn. 
The numerous varieties belonging to each class vary greatly as to 



the number of rows of kernels on the cob, as to the size, form, and 
color of the kernels, the length and diameter of the cob, etc. Only 
the dent and flint varieties have any considerable importance as grain 

An ear of maize consists of a thickened rachis or spindle, on which 
are inserted the closely-packed kernels 
with their accompanying chaff. The 
spindle and chaff together form the 

The kernels of a maize ear spring OTHflf ' \ 
from the cob transversely in pairs 

Fig. 53. Maize (Zea Mays). Cross sec- 
tion of ear looking toward the base. 
5 inner surface of lower empty glume 
seen behind flowering glumes and 
palets; s outer surface of upper 
empty glume; F axis; H depression; 
B bundle zone; M pith. Natural size. 


Fig. 54. Maize. Radial section of ear 
through the center of the kernels. 5 
and j empty glumes; j 2 glume and 
5 s palet of perfect flower; S 1 glume 
and S 2 palet of rudimentary flower; P 
spongy lining of thick glumes; U sur- 
face of woody zone beyond depression; 
H depression ; T denser portion of 
woody zone; B fibro-vascular bundle; 
M pith. X 4. (Winton.) 

and longitudinally in double rows. The arrangement is such that a plane 
perpendicular to the axis of the cob which passes through the bases of 
the pair in one double row will pass alternately between and through the 
bases of the pairs in the other double rows. Since the double rows of 
kernels are arranged in pairs, it follows that there are normally an even 
number of rows. In the early stages of ripening, the double rows are 
separated by marked grooves; but as the kernels approach maturity 
they become so crowded that the arrangement in pairs and double 

88 GRAIN. 

rows may not be outwardly apparent, but is evident on cutting into 
the cob. 

Fig. 53 shows, a cross-section of an ear so cut as to leave three of the 
six pairs of kernels entire, alternating with three pairs of fruit cups in 
section; Fig. 54 shows a longitudinal section. The core of pith (M) 
is surrounded by a zone (B) containing numerous fibro-vascular bundles 
running longitudinally through the cob and this in turn by an outer 
woody zone bearing the fruit cups. The woody regions (T) beneath 
the double rows are separated from each other by thin radial partitions 
of soft tissues extending from the central pith nearly to the surface. 
These partitions can be traced the whole length of the cob separating 
the woody matter into strips which are arranged about the pith like the 
staves of a barrel. The strips of woody matter are pierced for the 
passage of the tissues connecting the kernels with the zone of vascular 

On the surface of the woody zone between the pairs of fruit cups is 
a transverse depression (H) clothed with hairs, which is more or less 
pronounced according to the dryness of the cob. The woody matter 
(T) about these depressions is of a darker color than in other parts, owing 
to its greater density. The cups in which the kernels rest are formed 
by six envelopes, viz. : two empty glumes (S and s), the glume (s 2 ) and 
palet (S 3 ) of the perfect flower, and the glume (S 1 ) and palet (S 2 ) belong- 
ing originally to a rudimentary blossom. Both of the empty glumes are 
thick and horny with linings of spongy tissues (P) and thin ends re- 
sembling tissue paper. The other enveloping parts are entirely of this 
papery texture. Hairs occur at the bases of the thick glumes, espe- 
cially at their points of juncture, and also on the thin ends. The more 
or less flattened kernels are usually longer than broad in the dent va- 
rieties, but broader than long in the flint varieties. The ventral side 
(the side nearest the apex of the cob) is smooth and flat, while the dorsal 
side has a broad groove extending from the base of the kernel (where 
it is broadest and deepest) nearly to the apex. Beneath this groove is 
the unusually large germ (Fig. 62). 


Spindle. 1. The Epidermis overlying the woody zone in the depres- 
sions (Figs. S3 and 54, H) is made up of thin-walled cells of wavy out- 
line arranged more or less distinctly in rows (Fig. 55, ep). The hairs 


S 9 

{H, h) which spring from this epidermis are, in part, long, pointed, single- 
celled, with walls from one-third to one-sixth the thickness of the cavity, 

i H 

Fig. 57. Fig. 56. 

Fig. 55. Maize Cob. Surface view of ep epidermis and hy hypoderm in the depression 

(H, Figs. 53 and 54). H single-celled pointed hair; h blunt three-celled hair. X160. 

Fig. 56. Maize Cob. Radial section through depression (H, Figs. 53 and 54), showing 

epidermis with hairs, elongated and isodiametric sclerenchyma cells, fibro-vascular 

bundle and parenchyma of pith. X32. (Winton.) 
Fig. 57. Maize Cob. Transverse section through the elongated sclerenchyma of the 

woody zone. X160. (Winton.) 

and, in part, blunt, two or more celled, with exceedingly thin walls.. 

In the region between the depressions and the base of the upper thick 



glume (Fig. 54, U), the epidermis is like that of the homy portion of 
the empty glumes (Fig. 59). 

2. Woody Zone. The sclerenchyma cells of the woody zone vary 
greatly, according to their location, in form, size, and in the thickness of 
the walls. The first layer beneath the epidermis in the depressions, as 


Fig. 58. Maize Cob. Cross section of upper thick glume, ep epidermis with thick -walled, 
porous cells and thin-walled non -porous cells; st isodiametric cells; If longitudinally 
elongated sclerenchyma cells and fibre-vascular bundle; p parenchyma with compressed 
inner layers. X160. (Winton.) 

seen in the surface view (Fig. 55, hy), consists of elongated cells with 
porous walls usually narrower than the lumen. The side walls are much 
thicker than those at the ends. 

The cells of several succeeding layers are long and fibrous with narrow 
lumen, and extend in curves parallel to the surface of the depressions 
(Fig. 56). 

Proceeding inward from these layers, the cells gradually diminish in 



length and increase in width until they are finally round or oval. At 
first this change in shape is accompanied by a thickening of the ceil- 
wall; but further inward the walls begin to diminish in thickness and 
continue to diminish until the cells lose the character of sclerenchyma. 
All the transitional forms from woody fiber to the thin parenchyma of 
the pith are noticeable. 

Fig. 59. Maize Cob. Outer epider- 
mis of an empty glume, consisting 
of porous and non-porous cells and 
base of hair. X 300. (Winton.) 

Fig. 60. Maize. Membranous glume in 
surface view, ep outer epidermis with 
H long one-celled hair, and h short, 
blunt 1-3 celled hairs; * hair scar; p 
inner epidermis. X 160. (Moellee.) ' 

In cross-sections of the cob the thick cell-walls show not only numer- 
ous pores, but beautiful concentric markings (Fig. 57). 

3. Bundle Zone. The fibro-vascular bundles passing through the 
soft tissue between the woody zone and the pith have the characteristics 
peculiar to endogenous plants. In longitudinal sections, spiral, annular, 
scalariform, and pitted vessels and thin-walled elongated sclerenchyma 
cells are conspicuous (Fig. 56). 

4. The Pith consists entirely of parenchyma with thin cell-walls which, 
under high power, are seen to be pierced by pores: 

9 2 


Fig. 6i. Maize Cob. 
parts. X 1 60 

Hairs from different 


Empty Glumes. Each of the thick glumes (Fig. 54, S, s) is composed 
of a homy lower portion and a thin papery tissue at the end. 

The structure of the horny portion 
appears in cross section in Fig. 58. 
The epidermis (Fig. 59) is composed 
of two forms of cells, one with thick 
porous walls, the other with thinner 
walls free from, pores. Both forms 

yM ii II H \'i\\\\ R 111 are corninom y' rounded-rectangular, 
(O *U/ u O O O D *■> either isodiametric or somewhat elon- 
gated. The non-porous cells are some- 
times crescent-shaped, and often occur 

in pairs at more or less regular intervals, showing that they are analogous 

to the twin cells of other cereals. They are usually smaller than those 

with pores, although in some parts the difference in size is not so 

marked. In addition to these two forms 

of cells, hairs and well-developed sto- 

mata also occur in parts. The structure 

of the papery ends is like that of the 

thin glumes and palets. 

2. Sclerenchyma (Fig. 58, si and //). 
The sclerenchyma of the glumes extends 
from the epidermis nearly to the inner 
surface. In the first few layers, the cells 
are large, loosely arranged, more or less 
isodiametric, and have walls of mod- 
erate thickness; but further inward 
the cells are smaller, thicker walled 
and are longitudinally much elongated. 
The fibro-vascular bundles run among 
these elongated cells and parallel to 

3. Parenchyma (p). Toward the 
inner surface the cell-walls diminish in 
thickness and the sclerenchyma passes 
finally into parenchyma. The parenchyma cells of the inner layers are 
indistinct and much compressed. 

4. The Inner Epidermis is not evident. 

Flowering Glumes and -Palets (Fig. Co). 1. The Outer Epidermis 

Fig. 62. Maize. Longitudinal section 
of fruit. e pericarp; n remains of 
stigma; fs base of kernel; eg horny 
endosperm; ew floury endosperm; sc 
and jj scutellum of embryo; e epithe- 
lium of scutellum; k plumule; w (be- 
low) primary root; ics root sheath; 
iv (above) secondary root; st stem. 
X6. (Sachs.) 



(ep) consists of cells with thin wavy walls and thin-walled unicellular 
and multicellular hairs. 

2. The Inner Epidermis (p) is of elongated cells. 

tip :-;«.■ *^\^~eS».'j£^L* <£3 X ep 

Fig. 63. Maize. Cross section of bran coats and outer endosperm of fruit. Pericarp 
consists of ep epicarp, m mesocarp, p spongy parenchyma and sch tube cells; h spermo- 
derm; is perisperm; endosperm consists of K aleurone cells and E starch cells. X 160. 

Pericarp (Figs. 63 and 64). After soaking the grain for a day or two 
in water, a skin, having the same color as the' grain and consisting of 
the epicarp, mesocarp, and spongy parenchyma, may be readily sepa- 

sch / aj 

Fig. 64. Maize. Bran coats in surface view, m mesocarp; sch tube cells; p spongy 
parenchyma; is perisperm; K aleurone layer. X160. (Moeller.) 

rated. If yellow or white, this skin turns deep yellow with alkali; if 
red, it turns green. 

1. The Epicarp {ep) consists of porous-walled, elongated cells much 
like the corresponding layer of wheat, except that the walls are thicker. 
A thin cuticle covers the exposed surface. 

94 grain: • 

2. Mesocarp (m). Six or more layers of cells similar to those of 
the epicarp, but with thicker walls, constitute the mesocarp, or middle 
layer. In the outer layers these cells are 600 // or more long and 20-40 fi 
broad. In the inner layers, the cells are broader, flatter, and thinner 
walled, grading into those of the next layer. 

3. Spongy Parenchyma (p). Instead of a close layer of cross cells, 
such as occur in wheat, rye and barley, or isolated vermiform cells, as in 
rice and sorghum, we find in maize a spongy parenchyma made up of 
branching and anastomosing cells with narrow, radiating arms, and 
large intercellular spaces. In most parts the transversely elongated arms 
occur in the greatest numbers, indicating the relation with the vermiform 
cross cells of rice and sorghum. 

4. Tube cells (sch). In order to study the tube cells, also the spermo- 
derm and perisperm, a whole kernel should first be soaked in water, 
stripped of the outer pericarp, as already described, and the thick inner 
skin removed. This skin should then be boiled in ij per cent alkali, 
washed in dilute acetic acid, picked apart with needles, and the frag- 
ments mounted in chlorzinc iodine. 

Spermoderm (is). The so-called brown membrane, although ex- 
ceedingly thin, is readily seen in cross-section. It becomes intensely 
yellow on treatment with alkalies, without swelling perceptibly. A 
single layer of delicate elongated cells and traces of a second are dis- 
closed by the method described in the preceding paragraph. 

Perisperm (h). Beneath the spermoderm is still another layer which, 
although seen in cross-section only under the most favorable circum- 
stances, is brought out clearly in surface view by the method above de- 
scribed, the swollen walls remaining colorless, the finely granular con- 
tents, however, being stained deep blue. 

Endosperm (Figs. 62, 63 and 64). 1. The Aleurone Layer (K) con- 
sists, for the most part, of a single cell layer, although some of the cells 
are divided by tangential partitions. The cells are 30-40 // in diameter, 
the double walls 6-9 ji thick. 

2. Starch Parenchyma (E). Immediately adjoining the aleurone 
layer, the cells are small and flattened; further inward, large and is o- 
diametric. In the outer horny portion of the kernel, nearly all the starch 
grains (Fig. 65) are sharply polygonal, only a few being rounded; while 
in the inner mealy portion the reverse is true, nearly all the grains being 
rounded. A distinct hilum, often with radiating clefts, is always evident, 
at least in the larger grains. Most of the grains are 15-35 ft- Compound 

MAIZE. 95 

forms do not occur. T. F. Hanausek has aptly described the starch 
grains of maize as standing out in bold relief, in striking contrast with 
the flat grains of many starches. Examined with crossed Nicols, maize 
starch displays very distinct crosses. 

The Embryo (Fig. 62) contains oil and proteids, but no starch. 


The numerous products of maize serve not only as foods for man 
and beast, but also frequently as adulterants. 

Fig. 65. Maize Starch. X 300. (Moeller.) 

Whole Maize Products. Maize Meal. Finely ground whole kernel 
meal is an important human food in the Southern States. Coarse meal 
is fed to cattle, swine, and horses. 

Cracked Com is a coarser product used as a poultry food. 

From these products lumps of horny and floury endosperm and 
fragments of the bran and germ may be picked out under the simple 
microscope. The large polygonal starch grains (Fig. 65) differ from 
those of all other economic plants but sorghum. On treatment with 
alkali, yellow or white fragments of the skin become a deep golden- 
yellow and red fragments green. The pericarp is further characterized 
by the thick porous walls of the epicarp and mesocarp Fig. (64, m), and 
the star-shaped or transversely elongated cells of the spongy parenchyma 
(p). The tube cells (sch) are much like those of rice, oats, and 

Com and Cob Meal, often known as "cob-meal, " consists of the kernels 
ground with the cob. The characteristics of the cob are noted below. 

Flour and Other Decorticated Products. Maize Flour is an ingre- 

96 GRAIN. 

dient of some griddle-cake flours and various other preparations. It 
is also an adulterant of wheat flour. 

Maize Meal, prepared with or without removal of germ and bran, is used 
for making corn bread, " Johnny cake," and mush (" hasty pudding ") 

Hominy, or Grits, a coarser product made from white maize, is a 
well-known breakfast cereal. These and some other products consist 
largely of starchy endosperm. 

" Corn Flakes " is one of several cooked and flaked preparations, 
with distorted starch grains. 

Com Starch (p. 651). 

By-products. Gluten Meal and Gluten Feed are dried by-products 
from the manufacture of glucose. The former is a concentrated feed, 
consisting largely of hard, irregularly rounded, yellow lumps, the only 
marked microscopic elements being fragments of bran. Gluten feed 
cojitains more bran than does the meal. The starch grains are distorted 
in both products. 

Hominy Feed and Starch Feed, by-products containing starch}' matter 
and bran, are obtained in the manufacture of hominy and starch. 

Maize;JZake. The germs of maize' yield, on pressing, maize oil. 
Ground germ cake is sold under the name "germ oil meal." It contains 
no starch. 

Maize Bran, although much inferior to wheat bran, is frequently 
added to the latter as an adulterant, in which case it is detected by the 
cells of the epicarp, mesocarp, and spongy parenchyma (Fig. 64). 

Maize Cobs, because of their mechanical condition and low content 
of nutrients, have little value as cattle food. Their legitimate use is as 
fuel and for making smoking- pipes ; the ground cobs are, however, too 
often mixed with wheat or rye bran as an adulterant. 

In bran, thus adulterated, a practiced eye, even without the aid of a 
lens, will usually find fragments of the thin glumes and palets, also of the 
thick horny glumes and woody zone. Lindsey notes that by chewing the 
bran the hard woody fragments may often be detected. The thin glumes 
and palets (Fig. 60) can be examined directly under the microscope, 
noting the color on addition of alkali; but pieces of the thick glumes and 
the woody zone require special preparation. The characteristic epidermal 
cells (Fig. 59) of the empty glumes are obtained for study by warming with 
dilute alkali and scraping with a scalpel. For the identification of other 
tissues, sections should be cut with a razor or the elements isolated bv treat- 
ment with a macerating solution. Stone cells (Fig. 57), such as make up 


the woody zone of the cob and the interior of the thick glume, will be at once 
recognized as foreign to bran; and the same may be said of fibro- 
vascular bundles and the parenchyma of the pith. The compound hairs 
with thin walls, and sharp-pointed single-celled hairs with cavity five to 
six times the thickness of the walls, are unlike hairs of bran. Where the 
percentage of adulteration is large, chemical analysis will disclose a de- 
ficiency of nitrogen, fat, and starch and an excess of fiber. 

Usually the thin glumes (Fig. 60) with sinuous walls and hairs, also 
the porous and non-porous epidermal cells (Fig. 59) of the thick glumes, 
suffice for identification. 

Ground cobs from corn (maize) canneries are said to be used in cheap 
cocoanut candy. 


See General Bibliography, pp. 671-674; Berg (3); Bohmer (6, 23) ; Hanausek, T. F. 
(16); Harz(i8); Hassall(i9); Leach (25); Mace (26); Moeller^gJ; Planchon et Col- 
lin (34); Tschirch u. Oesterle (40); Villiers et Collin (42); Vogl (43, 45); Wittmack 

Also see Bibliography of Wheat, pp. 72-73. 
Bersch: Mais und Maisabfalle. Landw. Vers.-Stat. 1895, 46, 85. 
Harshbercer: Maize, a Botanical and Economic Study. Contrb. Bot. Lab. Univ. 

Pennsylvania I, 1893, 75. 
Linz: Beitrage zur Physiologie der Keimung von Zea Mais L. Dissert. Marburg, 1896. 
PAmmel: Comparative Anatomy of the Corn Caryopsis. Iowa Acad. Sci. 1897, 5, 1. 
White: Note on the Use of Maize as an Adulterant. Analyst, 1895, 20, 30. 
Winion: Die Anatomie des Maiskolbens mit besonderer Riicksicht auf den Nachweis 

von Kolbenmehl als Verfalschungsmittel der Weizen- und Roggenkleie. Oesterr. 

Chem.-Ztg. 1900, 3, N. F., 345. Conn. Agr. Exp. Sta. Rep. 1900, 186. 


A number" of plants formerly regarded as separate species of the 
genus Sorghum (S. saccharatum Pers., S. vulgare Pers., S. Cafjrorum 
Beauv., S. nigrum Roem. et Schult., S. cernuum Willd.) are now classed 
as varieties of a single species (Andropogon Sorghum Brot.), the extraor- 
dinary differences in their inflorescence and fruit being the result of 
hybridization and selection extending through centuries. These dif- 
ferences are especially marked, because some of the varieties have been 
developed for grain, others for brush, and still others for sugar; whereas 
in the case of other cereals the production of grain has been chiefly con- 

9 8 GR4IN. 

Broom corn (Andropogon Sorghum var. technicus Koern.), one of 
the most important varieties, is grown in large quantities in Illinois, 
Kansas, Nebraska, and some other states of the United States, and to 
a much lesser extent in Spain, Italy, and other parts of Europe. Al- 
though the grain is not fully ripe when the brush is in its best condition, 
still it is utilized to some extent as food for cattle and poultry, and some- 
times is mixed with wheat bran as an adulterant. 

A fertile spikelet (Fig. 66) and one or two staminate or rudimentary 
spikelets (r) are borne at each joint of the panicle. The fertile spike- 


Fig. 66. Broom Corn (Andropogon Sorghum var. technicus). Fruit with chaff, r two 
staminate spikelets; gi lower empty glume; g 2 upper empty glume; g, glume of rudi- 
mentary flower; gj flowering glume with awn; p palet; c caryopsis or fruit. X4- 

let consists of two shining, thick, empty glumes (gi and g 2 ) and three 
membranous, hairy envelopes, constituting the glume (g/) and small 
palet (J>) of the perfect flower, and the glume (g 3 ) of a rudimentary flower. 
A geniculate upwardly barbed awn, 5-7 mm. long, is borne on the glume 
of the perfect flower; but this awn, being readily detached by thresh- 
ing, is seldom found in the grain on the market. The grain or cary- 
opsis is about s mm. long and from 2-3 mm. wide, tapering to a 
blunt point at both ends. It varies in color from yellow-brown to 


Both Empty Glumes (Fig. 66, gi and g 2 ) are from 4 to 6 mm. long, 
equalling and closely enveloping the fruit. They vary in color from 
yellow-brown to red-brown. The soft hairs, which nearly cover the outer 
surface, are loosely attached and most of them are removed during the 
threshing and cleaning of the seed, leaving the glumes smooth and 



i. The Outer Epidermis (Figs. 67 and 68, aep) consists of thick- 
walled sclerenchyma cells several times as long as broad, with wavy con- 

Fig. 67. Fig. 68. 

FlG. 67. Broom Corn. Transverse section of empty glume and outer layers of fruit. Sp 
empty glume consists of aep outer epidermis, / fiber layer, p spongy parenchyma with 
g bundle, and iep inner epidermis with sto stoma; Fs pericarp consists of ep epicarp with 
. c cuticle, hy hypoderm, mes starchy mesocarp, q cross cells and sch tube cells; N peri- 
sperm with i swollen inner walls; E endosperm, consists of al aleurone layer and the 
starch cells with si starch grains and a proteid network. X 160. (Winton.) 
Fig. 68. Broom Corn, aep outer epidermis and / fiber of an empty glume in surface view. 
X300. (Winton.) 

tour, interspersed here and there with isodiametric hair-scars, each ac- 
companied by a crescent-shaped cell with granular contents. The hairs, 
which are almost invariably detached in preparing the mount, if not in 
cleaning the seed, are often 1.0 mm. long and 12 /x broad in the middle, 
but tapering towards both ends. Invariably the lumen is much broader 
than the walls. 

2. The Hypoderm Fibers (Figs. 67 and 68, /), of which there are 
several layers, have thick walls and narrow cavities. 

3. Spongy Parenchyma (Figs. 67 and 69, p). As seen in surface view, 
the cells of this layer are more or less rectangular with circular inter- 
cellular spaces, and resemble those of rice and barley glumes. 

4. Inner Epidermis (Figs. 67 and 69, iep). In cross-section this layer 
is not readily studied, since the radial walls are usually collapsed; but 
in surface preparations, the large elongated cells, often 150 p. long and 
50 n wide, interspersed with stomata and hairs, are clearly displayed. 



Flowering Glumes and Palet. i. Outer Epidermis (Fig. 70, aep). 
In general form the cells are similar to those of the outer epidermis of 
the empty glumes, but are narrower and much thinner walled. The 
marginal hairs (h) are long (often 500/*), single-celled, and pointed; 


Fig. 69. Broom Corn. Inner layers of 
empty glume in surface view showing p 
spongy parenchyma and iep inner epi- 
dermis with sto stoma and h hair. 
X 300. (Winton.) 

Fig. 70. Broom Corn. Glume 
of rudimentary flower (Fig. 
66, g 3 ) in surface view, aep 
outer epidermis with h one- 
celled hair and h 1 two- 
celled hair; iep inner epi- 
dermis. X 300. (WrxTON.) 

but on the surface, shorter hairs (h 1 ), with two or three joints and blunt 
ends, also occur. Both of these forms have exceedingly thin walls. 

2. The Inner Epidermis (iep) is distinguished from the outer by the 
straight walls, and almost entire absence of hairs. 

Pericarp. 1. Epicarp (Figs. 67 and 71, ep). The cells are longi- 
tudinally extended and have thick, wavy side walls, with more or less 
distinct pores. Hassack has noted that the cuticle (c) is of uneven thick- 
ness, due to minute granules or crystals, which may be seen either in 
section or surface view. 

2. The Hypoderm (hy) consists of from one to three layers of cells, 
with walls somewhat thinner than those of the epidermis. 



3. Starchy Mesocarp (mes). Several layers of thin-walled parenchyma 
cells, filled usually with small round or rounded polygonal starch grains, 
seldom over 6 fi in diameter, make up this coat. The starch appears 
during the early stages of growth and persists until the fruit nearly or 
quite reaches full maturity. As the caryopsis, even when nearly ma- 
ture, is intensely green owing to chlorophyl grains in the outermost layers 
of the mesocarp, it may be inferred that this starch is a direct product 
of assimilation in the pericarp. The presence or absence of a starchy 
mesocarp in the grain at the time of harvest is not a definite varietal pecu- 

FlG. 71. Broom Corn. Bran layers in surface view, ep epicarp; hy hypoderm; mes 
starchy mesocarp; q cross cells; sch tube cells; N perisperm; al aleurone cells. X 160. 

liarity, but is dependent on the ripeness of the fruit or other conditions. 
Some kernels of the same variety may possess it, while others show only 
empty, obliterated cells. Whether or not-the starch is present in a given 
seed may often be determined by careful scraping and observation with 
the naked eye. 

4. Cross Cells (q). These cells are usually long and narrow, being 
distinguished from the tube cells only by their transverse arrangement. 
Near the extremities of the seed they are, however, shorter and of more 
irregular shape. 

5. Tube Cells (sch). The cells of this layer lie at right angles to the 
cross cells. They are about 5 fi wide and often reach a length of 200 /*. 

Perisperm (N). This layer is frequently 50 ft thick. The outer radial 
walls are thin, but the inner wall (s) is greatly swollen. In surface view 
the large cells are conspicuous, not only because of their size, but because 
of their yellow or brown color. 

102 GRAIN. 

Endosperm, i. Aleurone Layer (al). The individual cells of this 
layer are characterized by their great variation in size and form. 

2. Starch Parenchyma (st). In the outer layers the starch grains, 
if present, are much smaller than in the interior of the seed, where they 
sometimes reach a diameter of 30 /i. They are usually sharply polygonal, 
with a distinct hilum and radiating fissures. The starch is surrounded 
by small protein granules, forming a network (a) which is especially 
evident after removing the starch by reagents. In some specimens, 
one or more of the outer cell layers are filled with these protein granules 
to the complete exclusion of the starch. 


The starch grains of broom corn and other sorghum fruits are practi- 
cally the same, both in form and size, as those of maize, although radically 
different from those of all other cereals. Meyer observed that the grains 
of some varieties of sorghum take on a reddish color, not a blue, with 
iodine solution, but Mitlacher found that this reaction takes place only 
after first soaking the grain in water. As a means of distinguishing 
sorghum starch from maize starch, this test is of little value, and it is neces- 
sary to depend on the differences in structure of other histological elements 

The epidermis (Fig. 68) of the glumes and the perisperm (Fig. 71, N) 
of both broom corn and sugar sorghum are radically unlike any tissues 
found in maize. Especially characteristic are the cells of the perisperm, 
which may be readily found without treatment with reagents, whereas in 
other cereals they can seldom be seen except under the most favorable 

After treatment with alkali, the epidermis (Fig. 68, aep) of the empty 
glumes may be readily distinguished from the corresponding tissues of 
maize by the longer cells, their zigzag contour and the crescent-shaped 
cells which almost invariably accompany the hair-scars. The thin glumes 
(Fig. 70) resemble those of maize (Fig. 60), but the epidermal cells are 
longer, narrower and less irregular in form. 

The tube cells of the two cereals are much the same, and the cross 
cells of sorghum are often not distinguishable from the spongy parenchyma 
cells of maize. Of the other tissues, the epicarp is not always character- 
istic, and the starchy mesocarp is difficult to find in the ground product. 

The elongated cells of the outer epidermis of the thick glumes in 
.sorghum and barley are much alike, but the short conical hairs, often 


unaccompanied by crescent-shaped cells, are characteristic of barley. 
Sorghum and oat glumes are not so readily distinguished by the epidermal 
tissues ; but in sorghum the cells of the spongy parenchyma are, like those 
of barley, irregularly rectangular with round intercellular spaces, whereas 
in oats they are star-shaped. 


See general Bibliography, pp. 671-674: Hassall (19). 
Brown: On Another New Pepper Adulterant. Analyst. 1887, 12, 89. 
Harz: Landw. Samenkunde. Berlin, 1885, 2, 1249. 
Hassack: Anatomie der Sorghum-Friichte. Mitth. aus dem Labor, f. Waarenk. an 

der Wiener Handels-Akad. 1887, 113. 
Mitlacher: Ueber einige exotische Gramineenfriichte, die zur menschlichen Nahrung 

dienen. Ztschr. allg. osterr. Apoth.-Ver. 1901, 813, 831, 856, 875, 899 u. 928. 
Winton: Anatomie der Kultur-Varietaten der Hirse. Ztschr. Unters. Nahr.-Genussm. 

1903, 6, 337. Conn. Agr. Expt. Sta. Rep. 1902, 326. 


Sugar sorghum (Andropogon Sorghum var. saccharatus Koern.) has 
been cultivated for many years in China and Africa and for the past half 
century in America. At one time it gave promise of being the chief sugar 
plant of the United States, but has since largely given place to the sugar 
beet. It is cut for sugar before the seeds reach maturity, but the latter 
still have some value as food for stock. When grown to maturity the seed 
is said to be equal or superior to durrha. 

Early Amber, Early Orange and other important varieties resemble 
closely the broom corns in habit of growth, but the panicles are shorter 
and less spreading. The two black, shining, empty glumes are of about 
the same length as those of broom corn, but are somewhat broader and, 
since they do not so closely envelop the caryopsis, are sometimes, - though 
not usually, removed in threshing. 

Numerous loosely attached hairs cover the surface of these empty 
glumes, but they, as well as the awned flowering glumes, drop off in the 
preparation of the grain for the market. 

Under the microscope the two varieties named cannot be distinguished 
from the broom corns except by the material in the epidermal cells of the 
empty glumes, to which they owe their black color. 

See Broom Corn, p. 103. 

104 GRAIN. 


Kaffir corn (Andropogon Sorghum (L.) Brot.) is the chief bread cereal 
and cattle food of the natives in parts of South Africa, and is an impor- 
tant product in parts of America. The fruit is borne in a dense head 
which does not bend over at maturity. 

The empty glumes are somewhat shorter than the fruit and the flower- 
ing glume is not awned. The caryopsis is white or red according to the 
variety, nearly globular, about 4 mm. in diameter and separates from 
the glumes in threshing. 

In microscopic structure Kaffir corn, aside from the absence of chaff, 
differs from the broom corns and sugar sorghums chiefly in that the peri- 
sperm is not evident either in cross-section or in surface preparation, and 
in that the hypoderm is more strongly developed, often consisting of three 
layers of thick-walled cells. 

White milo maize is but a subvariety. 

See Broom Corn, p. 103. 


Brown durrha, white durrha or Jerusalem corn, and yellow mila 
maize are forms of Andropogon Sorghum var. durra (Forskal) Hackel, 
differing from each other chiefly in the color of the caryopsis. They are 
grown to some extent in America for the grain, which is used as food for 
both cattle and poultry. The plants reach the height of 2 to 3 meters, 
but as the dense heads approach maturity, the rachis below them bends 
over, forming a goose-neck. 

Both of the empty glumes are obtuse, densely hairy, and about half 
the length of the large, flattened, more or less lenticular caryopsis, which 
is 5 to 6 mm. long and of about the same breadth. The flowering glume 
of white durrha is awned, but that of red durrha and yellow milo maize 
is awnless. As found in the market, the grain is usually free from all 

Although to the naked eye the fruits of the three varieties are much, 
alike except in color, under the microscope they show one marked differ- 
ence. In brown durrha the perisperm or nucellar layer is always strongly 
developed, whereas in the white and yellow varieties this layer is not evident. 



The other parts of the fruit are much the same as described under 
broom corn, but the outer layers of the endosperm normally contain 
only aleurone grains. 

See Broom Corn, p. 103. 



Rice (Oryza sativa L.), although not strictly a bread grain, furnishes 
daily food for more human beings than any 
other cereal. It is the chief food product in 
China, where it has been cultivated for nearly 
5000 years,- also in Japan, India, and other 
Oriental countries. Its culture has extended 
from the East to all the wanner regions of the 

The inflorescence is in panicles (Fig. 72, A) 
made up of single-flowered spikelets (B), each 
with two minute empty glumes, a thick, awned, 
conspicuously five-ribbed flowering glume, and 
an equally thick, three-ribbed palet, both the 
latter being strongly compressed and keeled. The 
flowering glume and palet are dull and lusterless, 
harsh and rasping to the touch, owing to numer- 
ous longitudinal -striations with transverse mark- 
ings, which, together with coarse hairs, are readily 
seen under a lens. The awn is seldom found 
on the threshed grain. The flattened fruit or 
caryopsis (K) is oblong, about 8 mm. long with 
blunt base and apex. The relief of the glumes 
is impressed on the surface, forming longitudinal 
grooves and ridges. The germ is situated on the **• yg <*2£t& 

dorsal edge at the base. -with chaff; Snaked fruit; 

F flower. (Nees.) 


Flowering Glume and Palet. Owing to the silica in the epidermis, 
rice glumes cannot be readily sectioned until after they have been soaked 



Maceration in Schulze's fluid serves to isolate 

for some time in alkali, 
the elements. 

i. The Outer Epidermis (Figs. 73 and 74, ep 1 ) consists of parallel 
longitudinal rows of large, thick-walled cells, square in general outline, 
with highly characteristic, very deeply sinuous side walls. Focusing on 
the outer walls, these side walls are seen to be compoundly sinuous. 

Stiff dagger-shaped hairs (t 1 ) up to 500 p long (usually 150-250 /1) 
and 40 /t in diameter at the base are scattered over the surface, being 

Fig. 73. Rice. Cross section of palet and outer portion of fruit. P palet consists of 
ep 1 outer epidermis with hair, / hypoderm fibers, p spongy parenchyma with jv bundle, 
and ep 1 inner epidermis with sto stoma;. F pericarp consists of epi epicarp, mes mesocarp, 
tr cross cells, and tu tube cells; 5 spermoderm; N perisperm; E endosperm consists 
of al aleurone cells, also starch cells. X160. (Winton.) 

especially abundant and also longest on the ribs and near the apex. 
The walls are 5-9 /* thick. 

2. The Hypoderm (/) consists of a double or triple layer of longi- 
tudinally-extended sclerenchyma fibers. In the outer layers, the fibers 
are strongly thickened and often have comb-like outgrowths, which join 
them one with another or with the epidermis. The inner fibers are thinner 
walled and have outgrowths only on the outer sides. 

3. Spongy Parenchyma (p). Two, sometimes more, layers of spongy 
parenchyma, through which run the bundles, form the mesophyl. The 
cells are rectangular, with thin wavy walls. Intercellular spaces occur, 
not only at the angles, but also between the surfaces of the walls. 



4. Inner Epidermis (ep 2 ). In cross-section, this layer of collapsed 
cells appears as a hyaline, striated membrane. Surface preparations 

Fig. 74. Rice. Layers of palet in surface view, ep 1 outer epidermis with x sinuous cells, 
t 1 hair, and y hair scar; / hypoderm fibers; p spongy parenchyma; ep 2 inner epidermis 
with sto stoma and t 1 hair. X 160. (Winton.) 

show that the cells over the bundles are elongated, but in other parts are 
more or less cubical. The cell-walls are thin and marked with delicate 
striations. Between these cells occur one- to three-celled (usually two- 
celled) very thin-walled hairs, also stomata, consisting of two peculiar 
guard cells and two somewhat larger companion cells with protoplasmic 

Pericarp (Fig. 73, F; Fig. 75). Sections are cut after removing the 
hulls and soaking for some hours in water. Fragments for surface ex- 
amination are obtained by boiling the grain for a few moments in ij 
per cent alkali, plunging in dilute acetic acid, and removing the outer skin, 
which readily separates after this treatment. 

1. Epicarp (epi). The outer layer of the fruit is the easiest found 
and the most characteristic. Unlike the epicarp of all the other cereals, 
the cells are transversely elongated, with curious, wavy, end walls. They 
are 120-500 p. long and 30-100 [i wide, and are arranged side by side 
in rows. 

2. Mesocarp (mes). Several layers of more or less compressed cells, 
indistinctly seen in transverse section, underlie the epicarp. In the first 
layer or two these cells are much like the cross cells of barley, but in the 


inner layers they are more elongated, passing into the vermiform cells 
of the next layer. 

3. Cross Cells (tr). As all the cells between the epicarp and tube 
cells are transversely elongated, increasing in length but decreasing in 
breadth from without inward, a sharp classification into two layers is 
obviously impossible. The cells of the inner layer, here designated as 


Fig. 75. Rice. Bran coats in surface view, epi epicarp; mes mesocarp; tr cross cells; 
tu tube cells; S spermoderm; N perisperm. X300. (Wintost.) 

cross cells, are strikingly distinct from the cross cells of wheat, rye, barley, 
and oats, but resemble closely those of maize, sorghum, and millet. They 
range in length up to 500 fi, but are only 4-6 /j. broad. As a rule they 
are nearly straight, but in parts they are bent and even branching. They 
Occur either united in a close layer or detached. 

Tube Cells (tu). The detached vermiform cells resemble strikingly 
those of the last layer, but are narrower, being but 3-5 p broad. They 
are the only cells of the pericarp, spermoderm, or perisperm that are not 
transversely elongated. 

Spermoderm (Figs 73 and 75, S). Cross-sections, previous to treat- 
ment with reagents, show only an indistinct structureless line between the 
tube cells and aleurone layer; but after heating with potash, washing in 
dilute acetic acid, and staining with chlorzinc iodine, the cuticle of the 
spermoderm is evident as a thin, yellow line, and the perisperm as a dark 
blue layer. After the removal of the tnin skin forming the pericarp, as 

RICE. 109 

already described, a second, thicker skin, consisting chiefly of spermoderm, 
perisperm, and aleurone cells may be separated by scraping. The spermo- 
derm is recognized by the thin cell-walls and the bright yellow color 
due to the thick cuticle. The more or less transversely or diagonally 
elongated cells resemble those of wheat and other cereals, but form only 
one layer. 

Perisperm (Figs. 73 and 75, N). As has been noted in the preceding 
paragraph, remains of the nucellus may be seen in section after treatment 
with potash and staining with chlorzinc iodine. In carefully prepared 
mounts the reticulated radial walls are evident. These cells are easily 
seen in surface view in mounts prepared as above described, and are 
distinguished from the cells of the spermoderm by the beaded appearance 
of the radial walls, due to reticulations, and their dark blue color. The 
cells are transversely elongated and are side by side in rows. 

Endosperm (Fig. 73, E). 1. The Aleurone Cells (al) are rounded 
polygonal, 25-40 p. in diameter, with uncommonly thin walls. 

2. Starch Parenchyma. The thin- walled cells contain starch grains 
(Fig. 76) 2-10 n in diameter often united into oval aggregates containing 

Fig. 76. Rice Slarch. X 300. (Moeixer.) 

from two to upward of a hundred grains. Grains from the center of a 
large aggregate have only flat facets, but those from the outer portion are 
curved on the exposed surfaces. Perfectly round grains arc rare. In com- 
mercial rice-starch one seldom finds aggregates, since they are usually 
broken up in the process of manufacture. The grains show distinct 
crosses with crossed Nicols, the hilum being centrally located. 

no GR4IN. 


Whole Rice. Rice is largely used as a human food in the form of the 
whole grain divested of the chaff, pericarp, spermoderm, the larger part 
of the germ, and some of the aleurone layer. 

Puffed Rice is made by the same process as puffed wheat (p. 70). 

Mill Products. Rice Flour and various other mill products are used 
in preparing infant and invalid foods, griddle cakes, puddings, etc. 

In all the products above named, the microscopic elements are starch 
grains (Fig. 76) , occurring as individuals or in aggregates, aleurone cells, 
and occasional fragments of other parts of the grain. 

Flaked Rice is a breakfast preparation, cooked ready for use. The 
starch grains are much distorted. 

Rice-starch (see p. 652). 

Rice By-products. Two by-products are obtained in preparing com- 
mercial rice : first, hulls or, more correctly, glumes and palets, and second, 
bran or middlings, consisting of the pericarp, spermoderm, germ, and 
fragments of the aleurone layer. 

Rice Hulls are useful as packing for eggs, bottles, etc. Owing to their 
harshness, as well as the lack of food elements, they are not fit for cattle 
foods. Ground rice hulls are, however, used for adulterating not only 
fodders, but cocoa, pepper, and other human foods. Fragments of 
sufficient size may be identified under a lens by the striations. If, while 
held by a needle, they are scraped with a scalpel, their rough, silicious 
nature is evident. Under the microscope, after treatment with alkali or 
macerating, the nearly square epidermal cells (Fig. 74, ep l ) with thick 
deeply zigzag walls and the broad dagger-shaped hairs (t 1 ) are highly 

Rice Bran or " Rice Polish " is a valuable fodder and a common 
adulterant of spices. It is composed not only of the elements of the 
pericarp, spermoderm, and germ, but also of aleurone cells and starch 
parenchyma, and often is contaminated with hulls. 

The most characteristic elements of the fruit are the epicarp cells 
(Fig. 75, epi) with zigzag end walls, but cross cells and tube cells also aid 
in identification. 


See General Bibliography, pp. 671-674: Bohmer (6, 23); Hanausek, T. F. (16, 17); 
Harz(i8); Hassall (19); Leach (25); Mace" (26); Moeller (29) ; Planchonet Collin (34); 


Tschirch u. Oesterle (40); Villiers et Collin (42); Vogl (43, 45); Wittmack 
Also see Bibliography of Wheat, pp. 72 and 73. 
Btjrchard: Reis und Reisabfalle. Landw. Vers.-Stat. 1896, 48, in. 
v. Hohnel: Die anatomischen Verhaltnisse der Reisspelze. Haberland's Wissensch.- 

prakt. Unters. auf dem Gebiete des Pfknzenbaues. I, 149. 
Street: Rice Hulls. New Jersey Agrl. Expt. Sta. Bull. 160, 1902. 


Oats {Avena sativa L.) are not only a valuable food for horses and 

other cattle, but also for the human family. For generations this cereal 

has been one of the chief articles of diet in Norway, Scotland, and Ireland, 

and within the last generation oat preparations have come into extensive 

■ use in America. 

The numerous varieties are grouped under two races: panicled oats, 
with loose inflorescence, and banner oats (A. orientalis Schreb.), with 
one-sided, contracted panicles. Belonging to both races, are naked and 
chaffy, awned and awnless varieties. Wild oats (A. fatua L.), with 

Fig. 77. Oats (Avena sativa). Cross section of flowering glume and fruit. Sp flowering 
glume consists of ep outer epidermis, / hypoderm fibers, p spongy parenchyma, and 
i inner epidermis; Fs pericarp consists of je epicarp and gu cross cells; K aleurone 
cells of the endosperm. X160. (Moellee.) 

geniculate awns, a common weed in grain fields, is believed by many 
botanists to have been the parent of the principal varieties in cultivation. 
The two or more flowered spikelets are subtended by two large, mem- 
braneous, empty glumes, which are left on the straw after threshing. 
In the common varieties, each grain is closely enveloped by the smooth, 
rounded, silicified, five or more veined, but not ribbed flowering glume, 
and the two-nerved, thin, palet. The flowering glume has narrow, thin, 



edges; the palet, broad, membraneous wings which clasp the fruit. The 


Fig. 78. Oats. Outer epidermis from the margin of the flowering glume, h hairs; 
/ crescent-shaped cells. X 300. (Moeller.) 

awn of the flowering glume, when present, is broken off in cleaning the 

Fie. 79. Oats. Elements of chaff (flowering glumes and palets) isolated by maceration. 
ep elongated cells, I crescent-shaped cells and K silica cell, all of the outer epidermis; 
h hair; / hypodcrm fibers.' X160. (Moeller.) 

grain. Freed of the chaff, the grain is spindle-shaped, with a silky -hairy 



shallow groove on the ventral side. The germ is about one-third the length 
of the fruit. 


Flowering Glume, i. The Outer Epidermis (Fig. 77, ep) consists 
of elongated cells with thick, wavy walls, twin cells (one of which is usually 
crescent-shaped), and circular cells. On the body of the glume the cell- 
walls are often thicker than the cavity (Fig. 79, ep) while on the edges 
(Fig. 78) they are much thinner. Hairs occur on the edge's, being most 

Fig. 80. Oats. Cells and hairs from 
membranous margin of flowering 
glume. X160. (Moeller.) 

Fig. 81. Oats. Inner layers of chaff (flowering 
glume or palet), in surface view. p spongy 
parenchyma; i inner epidermis with si stomata. 
X 300. (Moellee.) 

numerous near the apex. They are mostly rigid, thick-walled, dagger- 
shaped, broad at base (15-20 /i) and seldom exceed 60 ft in length. Some 
at the very edge are thin-walled, with a slight curve toward the end, giving 
them a peculiar, hooked appearance (Fig. 80). 

2. Hypoderm Fibers (Figs. 77 and 79, /), for the most part in 4-10 
layers, form a dense, hard coat. The individuals often exceed 1 mm. in 
length, and have thick, sparingly porous walls. As may be seen after 
maceration, the walls adjoining the epidermis are often toothed. 

3. The Spongy Parenchyma (Figs. 77 and 81, p) is distinguished from 
the corresponding layer of other cereals by the star-shaped form of the cells. 



4. The Inner Epidermis (i) consists of thin-walled cells and stomata. 

The Palet. The middle portion of the palet has practically the same 
structure as the flowering glume, except that the hypoderm layer is thinner; 
but the membraneous wings have an outer epidermis made up of thin-walled 
cells, and a rudimentary hypoderm or else no hypoderm whatever. Near 
the keels and parallel to them are rows of stomata, and on the keels are 
numerous stiff, thick- walled, pointed hairs about 15 p in diameter at 
the base and upward of 100 ft long. As the palet often breaks or bends 
on the keels these hairs form a highly characteristic saw-tooth edge. 

Fig. 82. Oats. Bran coats in surface view, je epicarp with long- hairs; jnt mesocarpj; 
qu cross cells; K aleurone cells. X 160. (Moellee.) 

Pericarp (Figs. 77 and 82). In cross-section the pericarp and spermo- 
derm do not show details of structure. The following characters may 
be observed in surface view: 

1. Epicarp. The cells on the body of the grain are longitudinally 
elongated, with thin, porous side walls, but at the apex and base are nearly 

OATS. 115 

isodiametric. The long hairs which clothe the apex often exceed 200 /i in 
length. They are usually broadest in the middle (about 20 /z), tapering 
toward both ends. The base is sometimes so narrow as to be hardly 
distinguishable from the apex. 

2. The Mesocarp or Middle Coat Qm) is ill-defined. 

3. Cross Cells (qu). The thin- walled, inconspicuous cells are arranged 
side by side in rows. 

The Spsrmoderm and Perisperm are not evident in the ripe grain. 

Endosperm (Figs. 76 and 82). 1. The Aleurone Layer (K) is commonly 
one cell-layer thick. The cells are 20-60 ji, and have thinner walls (double 
walls 5 jx or less) than in wheat, rye and barley. 

2. Starch Parenchyma. The large, thin- walled cells contain starch 
grains (Fig. 83) which for the most part are polygonal, and are collected 

Fig. 83. Oat Starch. X300. (Moeller.) 

in ellipsoidal or rounded aggregates (up to 60 ji) of from two to many grains. 
Among the simple grains are characteristic spindle-shaped forms. The 
individual grains seldom exceed 10 \i in diameter, and are commonly much 


Oats are commonly fed to horses and other farm animals without 
removing the chaff, and often without grinding. Ground oats are fre- 
quently mixed With other cereal products, particularly those containing 
less fibrous matter. Provender, a mixture of ground oats and maize, 
is one of the commonest horse feeds in the United States. 

The elements of chief importance in diagnosis are: first, the smooth, 
rounded (not ribbed as in barley) flowering glume, with an epidermis 
(Fig. 79, ep) of thick, wavy-walled, elongated cells, circular cells and 
twin cells, and with star-shaped (not rectangular as in other cereals) 

1 1 6 GRAIN. 

spongy parenchyma cells (Fig. 81, p); second, the palet of more delicate 
structure, having keels barbed with coarse hairs, forming saw-toothed 
edges; third, the epicarp with long, slender hairs (Fig. 82), often nar- 
rowed at the base; fourth, the rounded aggregates of polygonal starch 
grains and spindle-shaped forms (Fig. 83). 

Oatmeal, Rolled Oats, and similar "breakfast cereals," contain all 
the above elements except those of the chaff, though in some of these 
products the starch grains have been distorted by cooking. 

Oat By-products, consisting chiefly of chaff, are obtained in the manu- 
facture of breakfast cereals and are used in mixed cattle foods. They 
are inferior in nutritive value, being rich in fiber but poor in protein, fat 
and starch. The glumes and palets are distinguished from the corre- 
sponding parts of barley by the characters above named. 


See General Bibliography, pp. 671-674: Berg (3); Bohmer (6, 23); Hanausek, T. F. 
(16); Harz (18); Hassall (19); Leach (25); Mace" (26); Moeller (29); Planchon et 
Collin (34); Schimper (37); Tschirch u. Oesterle (40); Villiers et Collin (42); Vogl 
(43> 45); Wittmack (10). 

Also see Bibliography of Wheat, pp. 72 and 73. 
Emmerling: Ueber eine einfache Unterscheidungsweise von Gersten- und Haferspelzen. 

Landw. Vers. -Stat. 1898, 50, 1. 
White: Note on the Use of Maize as an Adulterant of Oatmeal. Analyst. 1895, 20, 30. 


Millet (Panicum miliaceum L.), an ancient cereal, is still extensively 
cultivated for grain in India, China, and Japan, and to some extent in 
Russia and other parts of Europe. In America it is grown only for green 
fodder and hay. 

The nearly globular fruit is tightly clasped by the flowering glume 
and palet, the whole forming an oval grain 3 mm. long and 2 mm. broad. 
Both envelopes are of a uniform buff or straw color and are smooth and 

Flowering Glumes and Palet. The Outer Epidermal cells on the palet 
and the central part of the glume are isodiametric or somewhat elongated, 
with compoundly sinuous side and end walls ; on the edges of the glume 
they are more elongated, with straight end walls. Both forms have 
smooth outer walls and are without colored contents. 


The Hypoderm Fibers, rectangular parenchyma cells without inter- 
cellular spaces, and the inner epidermis also of rectangular cells, are 
the same as in the glumes and palet of Setaria. 

The Caryopsis agrees in structure with that of Setaria viridls and S. 
Italica, except that the aleurone cells are 25-50 [i in diameter, whereas 
in Setaria they seldom exceed 20 /*. Vogl has shown that on treatment 

Fig. 84. Common Millet {Panicum miliaceum). Starch cells of endosperm showing (at 
the left) beaded network remaining after treatment with alkali. (Vogl.) 

with alkali the starch grains dissolve, leaving a beaded network corre- 
sponding to the form of the grains (Fig. 84). 


The chief products of millet are grits and the chaff and other by- 
products obtained in the preparation of grits. 

Millet grits contains starchy matter, large aleurone cells, and frag- 
ments of other bran elements. 

In chaffy by-products, the glumes and palets are distinguished from 
those of chaffy wheats, barley, oats, rice, maize, darnel, and chess by 
the absence of hairs, and of twin cells, and also by the rectangular paren- 
chyma cells without intercellular spaces; from those of German millet 
by the absence of wrinkles on the outer epidermis, and from those of 
green foxtail by the absence of both wrinkles and patches of brown tis- 


Hanausek, T. F.: Ueber die Matta. Ztschr. Nahr.-Unters. Hyg. 1887, 1, 24. 
Netolitzky: Mikroskopische Untersuchung ganzlich verkohlter vorgeschichtlicher 

Nahrungsmittel aus Tirol. Ztschr. Unters. Nahr.-Genussm. 1900, 3, 401. 
Vogl: Die wichtigsten vegetabilischen Nahrungs- und Genussmittel. Berlin u. Wien, 

1899. ns- 



There is good evidence that German millet or Hungarian grass (Seta- 
ria Italica Beauv., 5. panis Jesseri) was the chief cereal of the lake 
dwellers and other prehistoric races. In China as early as 2700 B.C. 
it ranked with rice as one of the staple crops, and is still an important 
cereal in the East. In other parts of the world it is grown largely for 
hay or for poultry food. Since German millet is regarded as but a form 
of green foxtail (Setaria viridis) developed by cultivation, it is not sur- 
prising that the fruits of the two agree closely both in macroscopic and 
microscopic structure. 

The glumes and palets are of a yellow or buff color, which aids in dis- 
tinguishing them from the spotted or dark envelopes of green foxtail. 
In other respects the two grains are not distinguishable. 


Hanausek, T. F.: Ueber die Matta. Ztschr. Nahr.-Unters. Hyg. 1887, 1, 24. 
Vogl: Die wichtigsten vegetabilischen Nahrungs- u. Genussmittel. Berlin u. Wien, 
1899, 135- 


Green foxtail {Setaria viridis Beauv., Chaelochloa viridis (L.) Scribn.) 
is a troublesome weed in both continents, particularly in the grain fields 
of the northwestern states of the United States. The seed has been 
found in American screenings in quantities varying up to 11.6 per cent. 

The inflorescence is in dense, bristly spikes, or rather spiked panicles, 
4-10 cm. long. Each spikelet consists of two empty glumes and two 
flowers, one perfect with coriaceous transversely wrinkled glume and 
palet, the other staminate with membraneous envelopes (Fig. 85). At 
the base of the spikelet are from two to four upwardly barbed bristles 
varying in length up to 8 mm, 


Empty Glumes and Glume of Sterile Flower (Fig. 85, g 1 , g 2 and 

g} 1 ). The lower empty glume is three-veined and less than 1 mm. long; 
the upper empty glume and the glume of the staminate flower are five- 
veined and 2 mm. long. In microscopic structure the three are practi- 
cally identical. 



i. Outer Epidermis (Fig. 86). Characteristic of this layer are the 
elongated cells with sinuous side walls and longitudinal rows of pits so 
arranged that one pit occurs in each concave bend of the wall. On 
the middle portion of the mature glume each of these pits is so large 
that it fills completely the bend of the wall and in addition has a thickened 
border, half of which coincides with the cell-wall, thus giving the tissue 
a lace-like appearance. This structure is optically delusive, the pit 


Fig. 86. Green Foxtail. Outer 
epidermis of the glume of the 
staminate flower. I at the edge; 
II in the middle. X 300. (Win- 

Fig. 8.5. Green Foxtail (Setarii viridis). I 
spikelet with ripe fruit: g l lower empty 
glume; g 2 upper empty glume; gj l glume 
and p 1 palet of staminate flower; gp glume 
and p 1 palet of fertile flower; c fruit or 
caryopsis; b bristles. II and III caryopsis 
enclosed by flowering glume and palet. 
X8. (Winton.) 

borders often appearing to be the cell-walls, but is resolved by careful 
focusing and comparison with the tissue in earlier stages of growth. 

In addition to these elongated cells, pairs of short cells, one isodia- 
metric, probably a hair-scar, the other more or less crescent-shaped, 
occur here and there, and less frequently stomata and thin- walled one- 
to three-jointed hairs. 

2. Mesophyl. Only about the nerves and the basal portions of the 
glumes is this coat evident. It has no diagnostic importance. 

3. The Inner Epidermis is composed of elongated cells with straight 

Palet of Staminate Flower (Fig. 85, p 1 ). Within the glume of the 
staminate flower is the palet, a hyaline scale only 1 mm. or less long with 

120 GRAIH. 

a notch at the end. In general structure, it is much the same as the other 
thin envelopes, but the cell-walls are thinner. 

i. Outer Epidermis. The narrow, elongated cells are wavy in outline, 
but pits are lacking or are indistinct. Isodiametric cells and thin-walled 
jointed hairs also occur. 

2. Inner Epidermis. Except at the base, where traces of mesophyl 
are sometimes evident, the inner epidermis immediately underlies the 
outer epidermis. 

Glume and Palet of Perfect Flower (Fig. 85, g} 2 , p 2 ). Both the glume 
and the palet of the fertile flower closely envelop the grain at maturity, 
the former being strongly convex, the latter flat except on the edges 
which clasp about the caryopsis. At the time of flowering these envelopes 
are thin and of a green color, but at maturity they are coriaceous, silici- 
fied and of a brown or mottled color. Under a lens, numerous transverse 
wrinkles are evident on the glume and on the middle or flat portion of the ' 
palet, the lateral portions of the latter which clasp the caryopsis being 
smooth and shining. 

1. Outer Epidermis (Figs. 87, 88, 89). Throughout the glume and on 
the middle portion of the palet, the cells are isodiametric or moderately 

Fig. 87. Green Foxtail. Outer epidermis of glume of fertile flower, showing the smooth 
edge and the wrinkled and mottled central portion. (Winton.) 

elongated and are arranged not only in longitudinal rows but also in 
irregular transverse rows, the wrinkles being formed by the outward bending 
of the cells at the end walls and the inward bending halfway between. 



At the time of flowering, it may be seen that at the outer surface the end 
walls are sinuous and the side walls are compoundly sinuous (Fig. 88, 7), 
but further inward the end walls are nearly straight and the side walls 
are simply, not compoundly sinuous (Fig. 88, II). At the end of each 


Fig. 88. Green Foxtail. Outer epidermis from middle of glume of fertile flower. I 
Outer surface and II inner surface soon after blooming. Ill Outer surface when in 
fruit. X 300. (Winton.) 

cell nearest the apex of the envelope, a cuticular wart bearing a group 
of pits is usually evident, particularly on the palet (Fig. 88, I). About 
these warts the adjoining end walls are more or less curved and the 
side walls are not so deeply sinuous. At maturity the cell cavity beneath 



the wart is conspicuous (on the palet nearly circular), but at the other 
end of the cell is narrow or not evident at all owing to the encroachment 

of the strongly thickened walls (Fig. 87; 
Fig. 88, III). 

The cell contents during the early 
stages of development are colorless, but 
later on usually become dark brown. 

The epidermal cells on the lateral or 
smooth portions of the palet which clasp 
about the caryopsis are longer, narrower, 
and less complex than those already de- 
scribed (Fig. 89). 

At maturity the wrinkles are usuaEy 
30-60 fi apart. 

2. The Hypoderm Fibers may be 
readily isolated by treatment on the slide 
with caustic alkali. They vary in length 
up to 0.6 mm. and are often toothed at 
the margin. 

3. Mesophyl. Rectangular paren- 
chyma cells without intercellular spaces make up this layer. Numerous 
chlorophyl granules are present at the time of flowering. 

4. The Inner Epidermis is composed of rectangular cells resembling 
those of the mesophyl. Both of these layers become more or less obliterated 
at maturity and are of no diagnostic importance. 

Pericarp (Figs. 90 and 91). The ventral side is flat and has a dark 
colored spot, the remains of the hilum, near the base. Extending half- 
way from the base to the apex on the dorsal side is a groove, which marks 
the position of the embryo. 

1. Epicarp. (ep). As in the outer epidermal layers of the floral 
envelopes the cells are elongated and wavy in outline. On the dark 
colored spot already referred to, the epidermal cells are more or less 

2. The Cross Cells (q) are similar to the tube cells in form, but are 
usually shorter, broader, and more irregular in shape. 

3. Tube Cells (sch). These are 2-4 n wide and often reach the length 
of 300 fl. 

Perisperm (iV). After treatment with alkali, this layer is clearly seen 
in surface view. The cells are of large size and have beaded walls. 

Fig. 89. Green Foxtail. Outer epi- 
dermis from edge of glume of fertile 
flower. X 300. (Winton.) 



Endosperm. 1. Aleurone Layer (al). The cells are 10-20 fi in 

% Starch Cells (Fig. 90, s). Polygonal starch grains' with conspicu- 

FlG. go. Green Foxtail. Cross section of outer portion of fruit. F pericarp consists of 
ep epicarp, q cross cells, and sch tube cells; N perisperm; E endosperm consists of 
al aleurone cells and s starch cells. X300. (Winton.) 

ous hilum fill the parenchyma cells of the endosperm. In the outer 
layers they are from 4-8 ft in diameter, but further inward they reach 
the maximum diameter of 18 ft. 

After dissolving the starch with alkali, there remains a network of 

FlG. 91. Green Foxtail. Bran coats in surface view, ep epicarp; q cross cells; sch tube 
cells; N perisperm; al aleurone cells. X300. (Winton.) 

threads containing conspicuous granules, which is very different from the 
network of homogeneous threads obtained from polygonaceous seeds. 

124 GRAIN. 

In this respect, however, this fruit cannot be distinguished from the 
fruits of S. glauca Beauv., S. panis Jessen, Panicum miliaceum L. (see 
Vogl) and other species of Panicum. 


The membraneous glumes with pores in the bends of the walls (Fig. 
86) and the coriaceous, transversely wrinkled, more or less spotted, 
envelopes of the fertile flower with compoundly sinuous, thickened cell- 
walls (Figs. 87 and 88) are highly characteristic of both green and yellow 
foxtail. These tissues are usually present in all stages of development. 

The fruit elements are like those of common millet and German 
millet. Treatment with alkali brings out the structure of the fruit coats 
and perisperm, and serves to distinguish this fruit from the common 

The starch is hardly distinguishable in form from the starch of bind- 
weed, but the network remaining after treatment with alkali is beaded. 


Winton: Ueber amerikanische Weizen-Ausreuter. Ztschr. Unters. Nahr.-Genussm. 
1903, 6, 433. Conn. Agr. Exp. Sta. Rep. 1902, 339. 


The fruit of this species (Setaria glauca Beauv., Chaetochloa glauca 
(L.) Scribn.) is larger than that of green foxtail, the envelopes are also 

proportionately larger (with the exception 
of the upper empty glume which is but 
half the length of the spikelet) and the 
wrinkles on the glume of the fertile flower 
are more pronounced (Fig. 92). 

In microscopic structure the fruits 
of the two species are identical. The 
floral envelopes are also much alike, the 
Fig. 92. Yellow Foxtail (Setaria only distinction being in the distance 

glauca). Fruit inclosed in flowering j- ,, . ,, ,, 

glume and paiet. z showing glume ; a P art of the wrinkles on the mature 

{Jo sho mu g palet l nd L ed ^ °l g l ume ' flowering glumes. In green foxtail this 
X 8. (Photograph by W. E. Brit- . ° 

ton.) distance is usually 30-60 fi, but in yellow 

foxtail it is often 80-120 fi. Since this 
distinction does not apply to the immature glumes and since the wrinkles 


I2 5 

on the palets of the two species are practically the same, it is often diffi- 
cult to identify the species in ground mixtures. Fortunately, identifica- 
tion of the genus is all that is usually required. 


The microscopic identification of darnel (Lolium temulentum L.) is 
important, as this fruit not only is one of the commonest impurities of 
European and Californian wheat, but also contains a poisonous prin- 
ciple (temulin) which renders it highly pernicious. 

The four- to eight-flowered spikelet is inclosed within a strongly- 
nerved empty glume which, however, is seldom 
found in the threshed grain. 

Adherent to each caryopsis is a flowering glume 
6-8 mm. long, and a two-keeled palet of about the 
same size but of thinner texture (Fig. 93). The 
flowering glume is obscurely five-nerved, lobed at 
the end, and bears an upwardly-barbed awn often 
15 mm. long. In cross section the caryopsis is 
U-shaped, owing to the deep groove on the ventral 


The Flowering Glume, like the glumes of barley, 
oats, and other cereals, consists of four coats, some 
of which, however, are lacking on the margins and 
at the end. 

1. The Outer Epidermis differs greatly in struc- 
ture in different parts of the glume. At the 
margins (Fig. 94) it consists of straight-walled, 
elongated cells interspersed here and there with short Fig. 93. Darnel {Lolium 

, , ii. r\ ax. 1 ^1 temulentum). a dorsal 

lance-shaped hairs. On the greater part of the sur- ^ e an( j j ventral side, 
face, however, the cells, as in barley and some other enlarged, c dorsal side, 

113.111X3.1 S1ZC* ^JNOBBE.J 

cereals, are of three kinds (Fig. 95) : first, cells of 
wavy outline, into which the straight-walled cells at the margin pass; 
second, circular cells corresponding to the conical hair-cells of barley; third, 
exceedingly short, more or less crescent-shaped cells. Near the margins 
and on the veins, where they alternate with stomata, the cells of wavy 
outline are elongated; but in other parts they are very short, often being 



broader than long. Although the cells are thick-walled, the walls are 
transparent, and the middle lamella is conspicuous, giving the impression 

Fig. 94. Darnel. Margin of flower- Fig. 95. 
ing glume showing lance-shaped glume, 

hairs. X 300. (Moeller.) 

Darnel. Middle portion of flowering 
X 160. (Winton.) 

of thin-walled cells. Pores are few and inconspicuous. Near the margin 
the circular cells are small and are usually accompanied by crescent- 
shaped cells which often exceed them in size. On the greater part of the 
glume, however, the circular cells are much larger, often being 70 // in 
diameter. Numerous pores are conspicuous, both in the radial and 
tangential walls. Often one, sometimes two, crescent-shaped cells ac- 
company a 1 circular cell. 

Characteristic of this coat are the short, wavy cells and the numerous 
circular cells, the latter frequently exceeding in area the former. 

2. Hypoderm. The fibers in this layer are much the same as in 
cereals. Fibers of similar structure also make up the ground tissue of 
the awn. 

3. Spongy Parenchyma. The elements are more or less rectangular 
in shape, like those of the corresponding layer of barley, and are readily 
distinguished from the star-shaped elements of oats. 

4. Inner Epidermis. This layer is made up of thin-walled cells 
and stomata, and is of no diagnostic importance. 

The Palet lacks a well-developed hypoderm layer except beneath the 

The Outer Epidermis is much the same as that of the flowering glume, 
except that it is barbed on the keels with rigid, thorn -like hairs 150 ft 
or less in length (Fig. 96). 



The Pericarp (Fig. 97, F; Fig. 98) consists of four coats, of which 
only two, the epidermis and cross cells, are fully developed. 

1. Epidermis (ep). Cross sections of the mature seed show that 
this layer consists of collapsed, moderately thick-walled cells, which are 

Fig. 96. DarneL Keel of palet showing outer epidermis with h hairs, and / hypoderm 
'fibers. X160. (Moellee.) 

Fig. 97. Darnel. Cross section of outer portion of fruit. F pericarp consists of ep epi- 
carp, m mesdcarp, q cross cells, and sch tube cells; 5 spermoderm consists of a outer 
layer and i inner layer; N perisperm; / fungus layer; E endosperm consists of al 
aleurone layer, and st starch cells. X160. (Winton.) 

best studied after heating with alkali. Seen in surface view, the cells 
at the apex of the seed are nearly isodiametric, but at other parts are 
elongated. The walls are indistinctly beaded. ' 

128 GR/IIN. 

2. The Mesocarp (m) is not developed on all parts of the seed, but 
is conspicuous on the angles. The cells vary greatly in shape and size, 

Fig. 98. Darnel. Bran coats in surface view, ep epicarp; m mesocarp; q cross cells; 
sch tube cells; a outer and i inner layer of spermoderm; N perisperm; / fungus layer; 
al aleurone cells. X160. (Winton.) 

some being irregularly isodiametric, others transversely elongated, re- 
sembling the cells of the next layer. 

3. Cross Cells (q). Especially striking are the cells of this layer, 
which resemble the cross cells of barley. The side walls are indistinctly 

4. Tube Cells, spongy parenchyma, and various intermediate forms 
(sch) make up the interrupted inner layer of the pericarp. 

Spermoderm (S). The cells are for the most part elongated and are 
often diagonally arranged with reference to the axis of the fruit. In trans- 
verse sections this coat often separates from the pericarp on the one hand 
and the perisperm on the other. Examined in water, only one cell layer 
(the inner) is evident: but successive treatments with 5 per cent alkali, 
dilute acetic acid and chlorzinc iodine, bring out two layers. 

1. The Outer Layer (a) is made up of thin-walled cells with cuticularized 
outer walls. Treated as above described, the cuticle is colored yellow- 
brown, the radial and inner walls, blue. 

2. The Inner Layer (i) is not only thicker than the outer, but the 
cells are thicker-walled and, in addition, swell greatly with alkali. These 

DARNSi. 129 

rswollen walls are stained deep blue by chlorzinc iodine, thus differentiating 
them from the yellow-brown cuticle on the inner wall. 

Perisperm (AT). Characteristic of this seed is the perisperm, con- 
sisting usually of two cell layers. In cross section these cells are rectan- 
gular with swollen walls; in surface view, as may be seen after soaking 
for a long time in dilute alkali, they are irregularly polygonal or more 
or less elongated. 

Fungus Layer (/). In most specimens a layer of fungus threads 20 [i 
thick is present between the perisperm and the aleurone layer. So com- 
monly is this fungus present in darnel grown in Europe, that it is of no 
little value in identifying the grain; but it remains to be determined 
whether in California, where the plant is a pest in wheat fields, the fungus 
is also a common accompaniment. After treatment with alkali this 
layer is stained bright yellow by zinc chloride iodine. 

Endosperm. 1. The Aleurone Cells (al) vary from less than 20 to 
40 [i in diameter. 

2. Starch Parenchyma (Fig. 97, st). The thin-walled cells contain 
small polygonal grains 3- 7 p. in diameter. The individual starch grains 
are not distinguishable from the grains of rice and oats, and like the 
latter often occur in aggregates of various sizes. 


The characteristic elements of darnel are the epidermis (Fig. 95) of 
the glumes and palets, and the fungus layer (Fig. 98, /) . The cross cells 
(q) and starch grains (Fig. 97, st) aid in identification, though the 
former may be readily confounded with the corresponding tissue of 
barley and the latter with the starch grains of oats. The spongy paren- 
chyma of the flowering glume resembles that of barley, but is readily 
distinguished from the spongy parenchyma of bat glumes. 

See General Bibliography, pp. 671-674: Mace" (26); Moeller (29); Villiers et 
Collin (42); Vogl (45)- 
Hanausek, T. F.: Vorlaufige Mittheilung iiber den von A. Vogl in der Frucht von 

Lolium temulentum entdeckten Pilz. Ber. deutsch. bot. Ges. 1898, 16, 203. 
Nestler: Ueber einen in der Frucht von Lolium temulentum L. vorkommenden Pilz. 

Ber. deutsch. bot. Ges. 1898, 10, 207. 
Vogl: Mehl und die anderen Mahlproducte der Cerealien und Leguminosen. Ztschr. -Unters. Hyg. 1898, 12, 25. 
Winton: Anatomie der Fruchte des Taumellolches und der Roggentrespe. Ztschr. 

Unters. Nahr.-Genussra. 1904, 7, 321. Conn. Agr. Exp. Sta. Rep. 1903, 165. 




Chess (Bromus secalinus L.) is one of the commonest weeds of grain 
fields, both in Europe and America, and the fruit is a common constituent 
of uncleaned grain, screenings, and various by-products. 

The fruit when invested by the flowering glume and palet closely 
resembles darnel, but the awn of the flowering glume is short or absent. 


Flowering Glume. The structure throughout is much the same as 
in darnel, but the cells of the outer epidermis (Fig. 99) are much more 

Fig. 99. Chess (Bromus 
secalinus). Outer epi- 
dermis of flowering glume 
in surface view. X 160. 

Fig. 100. Chess. Cross section of outer portion of fruit. 
F pericarp consists of ep, epicarp, and q cross cells; 
5 spermoderm; N perisperm; E endosperm consists of 
al aleurone layer, and st starch parenchyma. X160. 

conspicuously thick-walled, and the wavy-walled cells are throughout 
much longer than broad. The circular cells also have wavy walls. The 
cells on the margins, interspersed with lance-shaped hairs, are the same 
as in darnel. 

Palet. The flowering glume and palet are similar in structure, but 
the outer epidermis of the latter is barbed on the keel, the stiff hairs often 
reaching 45 11 in length. 

Pericarp (Fig. 100, F; Fig. 101). The pericarp consists of two layers 
with rudiments of another layer in parts. 

1. The Epicarp Cells (ep) are large, elongated polygonal, and haw 
thin, non-porous walls. 

CHESS. 131 

2. Mesocarp. As a rule, the cross cells immediately underlie the 
epidermis; but occasionally traces of the mesocarp are evident. 

3. Cross Cells (q). Whether this layer corresponds with the cross 
cells or the tube cells of other grasses is uncertain. The tissue is made 

Fig. ioi. Chess Bran coals in surface view, ep epicarp; q cross colls; S spermoderm; 
N perisperm; al aleurone cells. X160. (Wjcnton.) 

up of irregular spongy parenchyma cells, usually transversely elongated 
with large, round or elongated intercellular spaces. 

The Spermoderm (S) consists of one layer of elongated brown cells 
15-20 fi wide. 

Perisperm (N). This layer is enormously developed. As may be 
seen in cross section, the cells are 40 p.. thick, but trie walls are so swollen 
as to almost entirely obliterate the cavity. After soaking for some time 
in t^ per cent soda solution they are evident in surface view. 

Endosperm. 1. The Aleurone Layer (al) is "not of especial interest. 

2. The Starch-Parenchyma (Fig. 100, st) is remarkable for the thick- 
ness of the cell-walls (often 10 /j.) and the elliptical starch grains 3-20 [i 
in diameter. With proper illumination each grain may be seen to have 
an elliptical hilum. 

Especially characteristic are the thick-walled parenchyma cells (Fig. 
100, st) with elliptical starch grains. The cross cells (Fig. 101, q) also 
are of diagnostic importance. The epidermis (Fig. 99) of the flowering 

13 2 GRAIN. 

glume is distinguished from that of darnel by the bolder outlines of the 
wavy-walled cells and their greater length, as well as by the structure 
of the circular cells. The hairs on the keels of the palet are longer 
than those of darnel. 


Vogl: Die wichtigsten vegetabilischen Nahrungs- u. Genussmittel. Eerlln u. Wien, 

1899, 36. 
Winton: Anatomie der Friichte des Taumellolches und der RoggentreSpe. Ztschr. 

Unters. Nahr.-Genussm. 1904, 7, 321. Conn. Agr. Exp. Sta. 1903, 165. 

BUCKWHEATS {Polygonaced). 

Although buckwheat and other polygonaceous plants are botanically 
widely removed from the cereals, the fruits of the two families are quite 
similar in structure, as well as in chemical composition. In both, the 
pericarp is thin and dry, and the single seed consists of a thin spermoderm, 
a bulky endosperm with aleurone and starch cells, and a relatively small 
embryo. The following characters arc peculiar to buckwheats: (1) 
the thin leaf-like or colored perianth, (2) the brown or black pericarp, 
without hairs, (3) the network of homogeneous threads remaining after 
dissolving the starch grains in alkali. The structure of the spermoderm 
taken as a whole is also characteristic, although some of the layers are 
quite like tissues "found in the cereals. 

The starch grains are of the rice type, but they do not occur in rounded 


Nearly all the buckwheat raised in Europe and America as well as 
the larger part of that raised in oriental countries belongs to a single 
species (Fagopyrum esculentum Mcench), a native of Central Asia. Tar- 
tary buckwheat (F. Tartaricum Gsert), a less valuable species, is described 
in the following chapter. 

The sharply triangular, pointed, dark-brown or gray-brown achenes 
are 5-8 mm. long and 3-4 mm. broad. Fragments of the calyx are often 
attached to the base. A nerve passes longitudinally through the middle 
of each of the three sides. The seed completely fills the pericarp, but 
is not grown to it and is readily separated by machinery. On the other 
hand, the spermoderm adheres closely to the endosperm and is not en- 



tirely removed in milling. The embryo, with broad but thin cotyledons, 
is embedded in the endosperm, and is so folded that, in cross section, it ' 
is S-shaped. 


Pericarp (Figs. 102 and 103). Sections are cut after soaking for 
some time in water. Surface preparations are obtained by scraping 

Fig. 102. Buckwheat {Fagopyrum esculentum). Cross section of the pericarp at one 
of the angles showing the epicarp, the hypoderm of sclerenchyma elements with fibro- 
vascular bundle (g), the brown parenchyma (p), and the inner layers of obliterated 
cells. X160. (Moeller.) 

with a scalpel, after boiling for an hour in 1 \ per cent alkali to remove 
a- portion of the brown coloring matter. 

* » f 

Fig. 103. Buckwheat. Isolated elements of the pericarp, o epicarp; p parenchyma 
(the upper group from a bundle); / hypoderm fibers; ep inner epidermis; sp spiral 
vessel. X160. (Moeller.) 

i. The Epicarp Cells (0) are elongated, rounded quadrilateral and 
range up to 100 fi in length and 20 ;i in breadth. Diagonally extended 

134 GRAIN. 

pores on the outer wall, crossing those of the inner wall at nearly 
right angles, give the layer a peculiarly characteristic latticed appear- 
ance. Owing also to these pores the radial walls appear indistinctly 
beaded. On each of the three faces of the fruit the cells of both 
the epidermis and the hypoderm are pinnately arranged either side of 
the central vein, but on the angles of the fruit they are longitudinally 

2. The Hypoderm (/) consists of several layers of short fibers (up 
to 150 [x long, 10-15 I 1 broad), with thick porous walls. The narrow 
cavities contain a brown substance. 

3. Brown Parenchyma (p). Only a single thin layer of parenchyma 
is present in the faces of the pericarp, but in the angles there are several 
layers. The cells are either isodiametric or elongated, with rather thick 

walls impregnated with a brown sub- 

m ' stance. This same substance is also 

^g found in the other layers, though in 
smaller amount. Through this tissue 
pass the bundles of the veins. 

4. An Endocarp (ep), for the most 
part of large, elongated, mostly pointed 
S> »„'_'„§ & • © Q ce n S) w ; tn SO mewhat thickened walls, 

Fig. 10 1. Buckwheat. Cross section covers the inner surface. 

of outer portion of seed. Spermo- 

derm consists of outer epidermis, bpermoderm (l"lgS. 104 and 105). 

m spongy parenchyma, and ep inner After the remova l f tne pericarp the 
epidermis; endosperm consists of r r 

K aleurone cells and E starch cells, seed is seen to be covered with a thin, 

Xl6o. (MOELLER.) ,, . t , , . , . . 

yellowish membrane, which is best ex- 
amined in cold dilute alkali. The three superimposed layers are easily 
found on careful focusing. 

1. Outer Epidermis (o). Wavy-walled cells, isodiametric or some- 
what elongated, form a conspicuous epidermal layer. 

2. Spongy Parenchyma (m). Cells of various shapes, with numerous 
round intercellular spaces, underlie the epidermis, and with it form a 
most valuable means of identification. Greenish or brownish-yellow 
cell contents render this layer particularly distinct. 

3. An Inner Epidermis (ep) of elongated, thin-walled cells, is readily 
found after the addition of cold dilute alkali. 

Endosperm (Figs. 104 and 105). 1. Aleurone Cells (K) similar to 
those of the true cereals form an outer coat one cell layer thick. In 
cross section the cells are seen to be somewhat tangentially extended. 



Surface mounts show that the cells are exceedingly variable both in size 
and wall thickness. 

2. Starch Parenchyma (E). Cells of large size with thin walls contain 
the densely crowded, polygonal starch grains (Fig. 106). Isolated cells 

Fig. 105. Buckwheat. Bran coats in surface view. Spermoderm consists of outer 
epidermis, m spongy parenchyma, and ep inner epidermis; K aleurone cells. X300. 

(Fig. 107) closely packed with grains are the most striking constituents 
of mill products. The starch grains range from less than 2 to over 15 ft 

Fig. 106. Buckwheat Starch. X300. (Moeller.) 

but are commonly 6-12 /i. They are either round or more commonly 
rounded polygonal and usually display a conspicuous hilum. Although 
the grains are never united into circular or elliptical aggregates, such as 
occur in rice, oats, and darnel, two or more of them are often joined to 
form a rod-like aggregate. As noted by Vogl these aggregates are often 
curiously constricted, and the contact surfaces of the individuals are 

i 3 6 


Vogl also found that, on treating the starch masses with alkali, there 
was obtained a network of homogeneous threads (Fig. 108), not beaded 

Fig. 107. Buckwheat. Starch grains in masses. Xno. (Leach.) 

as in Setaria and Panicum, corresponding to the outline of the dissolved 
grains. This phenomenon is also common to various species of Poly- 
gonum and Rumex and is probably characteristic of the entire family. 


Fig. 108. Buckwheat. Starch cells of endosperm Fig. ioq. Buckwheat. Longitudinal 

showing at the left network of homogeneous section of cotyledon. epidermis i 

threads remaining after treatment with alkali. p mesophyl; g procambium or in- 

(Vogl.) cipient bundle. (Moeller.) 

Embryo (Fig. 109). As appears in cross section, the two cotyledons 
consist of a mesophyl (p) between an outer and inner epidermis, and the 
elongated cells of the procambium (g) or incipient bundle running through 
the mesophyl. 

The Mesophyl consists of small, polygonal cells with protoplasmic 
contents, the epidermis, of somewhat larger and more sharply defined 
cells of more or less elongated form. 



The whole grain is esteemed in Europe as a poultry food. It is seldom 
ground with the hulls. 

Decorticated Products. Buckwheat Flour is employed, especially in 
America, for making griddle cakes. To the touch it has a peculiar harsh- 
ness quite unlike the soft feeling of wheat and rye flour. It consists of 
parenchyma cells packed with starch grains (Fig. 107), isolated starch 
grains (Fig. 106), and occasional fragments of the spermoderm (Fig. 105). 

The individual starch grains are much like those of oats, rice, and 
darnel, but they are never united into rounded aggregates. They are 
distinguished from Selaria and Panicum starch by the network of homo- 
geneous threads left after treatment with alkali (Fig. 107). The rod- 
shaped and constricted aggregates are characteristic. Of greatest value 
in diagnosis are the fragments of the spermoderm (Fig. 105), consist- 
ing of the wavy-walled cells of the outer epidermis, the spongy paren- 
chyma with greenish cell-contents and the elongated cells of the inner 

Buckwheat flour is often adulterated with cheaper flour. Of 107 
samples examined in 1900 by the author, 26 contained wheat flour or 
wheat middlings, 9 maize flour, and 9 both wheat and maize flour. 

Prepared or Self-raising Buckwheat Flour are names applied in 
America to griddle-cake preparations containing such proportions of salt 
and baking-powder that they may be prepared for cooking by simply 
mixing with water or milk. The flour in these preparations is either 
pure buckwheat flour or various mixtures of buckwheat, wheat, maize, 
rice, and barley flour. If, as is usually the case, the baking-powder used 
contains corn-starch as a filler, traces of this starch will be found under 
the microscope. 

Buckwheat Grits is a valuable food for the common people in Russia 
and some oriental countries. It contains the same elements as the flour. 

By-products. Buckwheat Middlings, a by-product from the manu- 
facture of the flour, is readily identified by the tissues of the spermoderm 
(Fig. 105). It is used as a cattle food and also as an adulterant of spices. 

Buckwheat Hulls have little food value, but make good packing. 
They have been extensively ground for adulterating black pepper. The 
latticed epicarp cells (Fig. 103, 0) and the hypoderm fibers (/) are of chief 
value in identification. 

138 GRAIN. 


See General Bibliography, pp. 671-674: Bohmer, (6, 23); Hanausek, T. F. (10, 
16); Harz (18); Leach (25); Mace" (26); Moeller (29); Planchon et Collin (34); 
Schimper (37); Tschirch u. Oesterle (40); Villiers et Collin (42); Vogl (43, 45); 
Wittmack (10). 

Also see Bibliography of Wheat, pp. 72 and 73. 
Hanausek, T. F.: Reis- und Buchweizenstarke. Chem. Ztg. 1894, 18, No. ^3- 
Meyer, Arthur: Arch. d. Pharm. 1883, 912. 
Tschirch: Starkemehlanalysen. Archiv. d. Pharm. 1885, 23, 521. 


Indian wheat, Tartary buckwheat, or duckwheat (Fagopyrum Tartari- 
cum Gaertn.) is known chiefly in the East. In Piedmont and some other 
cold, mountainous regions, it has been grown to some extent, as it ripens 
earlier than the common sort. 

The grains are dull brown and have a marked longitudinal groove 
running through each of the three faces. 


Pericarp. 1. The Epicarp Cells are isodiametric or somewhat elonga- 
ted with thin, non-porous walls. On the inner surface they are convex, 
fitting into corresponding concave depressions of the next layer. 

2. ITypoderm. In the outer two or more layers the fibers are trans- 
versely extended, but in the inner layer they are arranged longitudinally. 

3. The Brown Parenchyma is much like that of common buckwheat. 

4. An Endocarp of thin-walled cells completes the pericarp. 

The Spermoderm, Endosperm, and Embryo are the same as in common 


Of the several common weeds belonging to the genus Polygonum, 
black bindweed or wild buckwheat (P. Convolvulus L.) is the most trouble- 
some. Although a native of the Old World, it thrives luxuriantly in the 
grain fields of the United States, and the seed is the chief impuritv of Ameri- 
can wheat. Samples of wheat screenings from the leading wheat-growinc 
states of the Union contained from 8 to 27 per cent of this seed. 

The jet black, lusterless, triangular achenes are 3 mm. long and the faces 
are 2 mm. broad (Fig. no, II). Since the achenes at maturity are closely 


invested by the calyx (/), both are harvested together; but during thresh- 
ing, screening, and transportation, the dry calyx, as a rule, is removed 

i n 

Fig. no. Black Bindweed {Polygonum Fig. in. Black Bindweed. Cross section of 
Convolvulus). I Fruit with calyx. fruit. C calyx; Epi epicarp; Mes meso- 

II Fruit without calyx. XS- (Win- carp; B nbro-vascular bundle; S spermo- 

TON.) derm; E endosperm; Em embryo. X16. 


from the achenes, and the pericarp, splitting at the angles, is often sepa- 
rated from the seed. 

The seed consists of a thin, colorless spermoderm, a starchy endosperm, 
and a minute embryo situated in a longitudinal groove of the endosperm 
at one of the angles. 


Calyx (Figs, in and 112, C). The three outer lobes of the five- to 
six-lobed calyx are broader than the others and are slightly keeled at the 

1. Outer Epidermis (Fig. 112, aep). Distributed over the outer surface 
are numerous characteristic blunt-conical or nipple-shaped papillae from 
30-60 n in diameter at the base, each of which is marked with longitudinal 
striations. These papilla?, as may be seen in transverse section, are 
the outer portions of the epidermal cells, the inner portions forming a 
continuous cell layer. 

2. Mesophyl (m). Between the outer and inner epidermis are several 
layers of chlorophyl-containing parenchyma with intercellular spaces. 

3. Inner Epidermis (iep). Elongated cells with more or less wavy 
outline and varying in length up to 200 // and in breadth from 1 5-45 fi } 
interspersed here and there with stomata, make up the inner coat of the 

Pericarp (Figs. 113-115). The black hulls or shells of the grain should 
be studied in cross section and in surface preparations, the latter being 



freed from the black coloring matter by warming on the slide with caustic 
alkali, or better by boiling for half an hour with i\ per cent sodium hydrate 
solution as in the determination of crude fiber. 

i. Epicarp (epi). Cross sections show that the cells are about ioo fi 
in radial diameter on the sides of the achenes and are still longer at the 

Fig. 112. Black Bindweed. Cross section of calyx and angle of fruit. C calyx consists 
of aep outer epidermis, m mesophyl, and iep inner epidermis; F pericarp consists of 
epi epicarp with w cuticular wart, p mesocarp, and end endocarp; 5 spermoderm con- 
sists of ae outer epidermis, q cross cells, and U inner epidermis; E endosperm consists 
of al aleurone cells and s starch cells. X 1 6o. (Winton.) 

angles. The inner wall is thin, but the outer wall and the outer portions 
of the curiously wrinkled radial walls are strongly thickened. Proceeding 
from the inner wall outward, the radial- walls increase in thickness until 
the much-branched cell cavity is almost obliterated. On the surface 
are numerous warts from 15-30 fi in diameter, into each of which a narrow 
branch of the cell cavity passes. 

Surface preparations of the pericarp with the outer surface upper- 



most clearly show that the warts are arranged in irregular longitudinal 
rows, also that the epicarp cells at the surface are sinuous in outline 

Fig. 113. Black Bindweed. Epicarp in 
surface view showing wavy outline of 
cells and cuticular warts. X 1 60. 

Fig. 114. Black Bindweed. Tangential 
section of epicarp. X160. (Wrs T - 


(Fig. 113), but further inward gradually approach a circular form 
(Fig. 114). 


Fig. 115. Black Bindweed. Surface view of pericarp from below, epi epicarp; hy 
hypoderm; p mesocarp with g bundle. X160. (Wixtox.) 

As may be seen in preparations of the pericarp with the inner surface 
uppermost, the contour of the inner cell-walls of the epicarp is, like the 
outer wall, sinuous in outline (Fig. 115, epi). 



2. Hypoderm (Figs. 112 and 115, hy). Beneath the epicarp is a layer 
of slightly elongated parenchyma cells somewhat larger than the cells of 
the mesocarp. 

3. Mesocarp (p). At the angles of the fruit this layer is somewhat 
thicker than on the sides. The cells of the ground tissue are thin-walled 
and isodiametric, those of the inner layers being more or less obliterated 
in the ripe fruit. Six primary, sparingly branched vascular bundles 
pass longitudinally through the ground tissue of the mesocarp, one in 
each angle and one in each of the faces. 

4. Endocarp (Fig. 112, end). Like the inner mesocarp, the cells are 
usually obliterated in the mature seed and are seldom evident either in 
cross section or in surface view. 

Spermoderm (Fig. 112, S; Fig. 116). Three coats, analogous to those 
of buckwheat, but differing in form, make up the spermoderm. 

Fig. 116. Black Bindweed. Seed in surface view, ae outer epidermis, q cross cells, and 
ie inner epidermis of spermoderm; al aleurone cells. X160. (Winton.) 

i. Epidermis {ae). As in buckwheat, the epidermal cells are wavy 
in outline; but they are strongly elongated, whereas in buckwheat they 
are nearly isodiametric. 

2. Cross Cells (q). Most of the cells of this layer are elongated, 
resembling the tube cells of cereals; but short cells of more irregular shape 
also occur, particularly near the base and apex. In no part do they form 
a spongy parenchyma with circular intercellular spaces like that of buck- 


3. Inner Epidermis (ie). The coat consists of thin-walled, elongated 

Endosperm (Figs, in and 112, E). None of the elements are dis- 
tinguishable from those of buckwheat, cither in form or size. 

1. Aleurone Cells (Figs. 112 and 116, al) are of variable size and 
irregular shape. 

2. Starch Cells (Fig. 112, s). In the outer layers the cells are tangen- 
tially elongated ; further inward, they are radially elongated and of large 
size. The polygonal or rounded grains vary in diameter from 3-12 /1. 

As in buckwheat and other species of Polygonum and Rumex, a network 
of homogeneous threads, corresponding to the outline of the starch grains, 
remains behind after dissolving out the starch in alkali. 

The Embryo, consisting of an elongated radicle and two oblong coty- 
ledons, may be conveniently isolated by soaking the seed in ij per cent 
caustic soda solution for some hours until the starch is removed. 


Ground screenings containing a large percentage of this seed has 
been sold in the United States as a fodder ("Germ Middlings," etc.), and 
has been used as an adulterant of ground pepper. Fragments of the 
seed, particularly the black hulls, are frequently encountered as an acci- 
dental impurity in bran and other by-products. 

' Characteristic of this fruit are the papilla? on the outer epidermis 
(Fig. 112, aep) of the calyx, also the epicarp (Fig. 113) with sinuous cell- 
walls and rows of warts. 

The outer epidermal cells (Fig. 116, ae) of the spermoderm are 
sinuous in outline, like those of buckwheat, but are commonly more 

Although the cross cells (q) are morphologically the same as the spongy 
parenchyma of buckwheat, they resemble more nearly in structure the 
tube cells of the cereals. 

The starch grains, also the network of homogeneous threads obtained 
after treatment with alkali, are characteristic of the family, not of the 


Kraus: Pringsh. Jahrb. f. wissensch. Bot. 1866, 5, 83. 

VnxiERS et Collin: Traite des Alterations et Falsifications. Paris, 1900, 103. 
Winton: Ueber amerikanische Weizen-Ausreuter. Ztschr. Unters. Nahr.-Genussm. 
1903, 6, 433. Conn. Agr. Exp. Sta. Rep. 1902, 339. 

1 14 GRAIN. 


A number of European and American species of Polygonum and 
Rumex are troublesome weeds. 

The black or brown seeds are either triangular or flattened, rough 
or more commonly lustrous. 

The anatomical structure of most of them resembles that of black 
bindweed. The epicarp cells in surface view are commonly sinuous 
with or without cuticular warts; the starch grains polygonal, of the buck- 
wheat type. 


Of the weeds which infest grain fields, some are so low-growing that 
they escape cutting with the grain, others ripen their seed before or after 
the grain is harvested, and others still, including some of the rankest 
weeds, have such small seeds that they do not appreciably add to the 
weight of the grain. Of the seeds harvested with the grain by far the larger 
part, being larger or smaller than the grain, are separated as screenings, 
so that the cleaned grain is nearly, although never quite, free of foreign 

European Screenings. According to Vogl the commonest weed seeds 
of European grain are Agrostemma Githago L. (cockle) and legumes, 
although the following occur in considerable quantities: Vaccaria parvi- 
flora Moench (cow herb) ; Species of Galium (bed straws) ; Bi}ora radians 
M. B.; Bromus secalinus L. (chess); Lolium temulentum L. (darnel); 
Avena jatua L. (wild oats); Centaurea Cyanus L. (corn flower); Papaver 
RhoeasL,. (corn poppy); Lithospermum aruense~L.; Species of A triplex; 
Convolvulus arvensis L. (small bindweed); Species of Polygonum, espe- 
cially P. Convolvulus L. (black bindweed) ; Melampyrum arvense L. (cow 
wheat); Alectorolophus hirsutus Allion; Delphinium Consolida L. (lark- 
spur); Ranunculus arvensis L. (buttercup); etc. Fruits of species of 
Setaria (foxtail) and some umbelliferous plants, seeds of cruciferous 
plants, etc., occur only in small amounts. 

In a sample of wheat screenings from one of the largest steam mills 
near Vienna, Vogl found: broken wheat 41.7 per cent, cockle 42.7 per 
cent, legumes 6.4 per cent, bed straws 3.3 per cent, Atriplex 3.1 per cent, 
Polygonum species 1.1 per cent, miscellaneous 0.6 per cent; while in 
another sample he found broken wheat, etc., 42.1 per cent, cockle 29.7 
per cent, legumes 11.1 per cent, Bijora radians 4.9 per cent, bed straws 
3.5 per cent, Polygonum species 2.0 per cent, cow wheat 2.5 per cent, 
cruciferous species 1.4 per cent, miscellaneous 2.3 per cent. 

A sample of so-called "tares" consisted chiefly of legumes with 



small amounts of broken wheat, cockle, etc. One known as " chicken or 
small wheat" consisted largely of small wheat kernels mixed with chess 
(4.3 per cent) and other fruits and seeds, including three kernels of foxtail. 

The foreign matter in a sample of uncleaned wheat was chess, cockle 
and small amounts of other impurities, including two fruits of black bind- 

American Screenings. The chief wheat-growing regions of America 
may be divided into three sections: First, the spring wheat section of 
the middle west, including Kansas, Ohio, Indiana, Missouri, Illinois, 
southern Nebraska, southern Michigan, and the adjoining states to 
the south; second, the winter wheat section of the middle northwest, 
including the states of Minnesota, North Dakota, South Dakota, Iowa, 
"Wisconsin, northern Nebraska, and Canada; third, the Pacific section, 
including the states of California, Oregon, and "Washington. 

Botanical analyses of screenings from the first two of these sections 
are given on p. 147. 

From these it appears that the screenings of the Old and New World 
are quite different at the present time. Of the two chief constituents 
of European screenings, cockle occurs in small amount and leguminous 
seeds less often in the American product, while the three leading seeds 
of American screenings (black bindweed, green foxtail, and yellow fox- 
tail), although introduced from Europe, are of minor importance in 
their native land. Chess is often met with in considerable amount on 
both continents. 

No analyses of screenings from the Pacific coast are available, but 
it is well known that the product differs markedly in constitution from 
that of the East. 

Hilgard 1 in 1890 stated that in California all of the species of Poly- 
gonum excepting P. aviculare were almost unknown, and chess, although 
found here and there, had failed to gain a foothold as a weed. 

Darnel (Lolium temulentum L.) and wild oats (A vena jatua L.) were 
named, however, as serious pests in the California wheat fields. 

Uses of Screenings. The seeds of charlock are separated in large 
quantities from the screenings of the spring wheat section of the United 
States, and are used as a substitute for true mustard. It is probable 
that most of the samples described in the table on p. 147 represent the 
residue after this separation. 

Screenings are particularly adapted for poultry food, as poultry pick 

1 California Agricultural Experiment Station Report, 1890, p. 238. 







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out the valuable seeds one by one, avoiding any that are distasteful. 
They are also used for feeding sheep, swine, and other farm animals. 
In Chicago, New York, and some other grain centers, ordinary screenings 
are separated into two products, one consisting largely of broken and 
shrunken wheat, the other of weed seeds, notably black bindweed, green 
foxtail and yellow foxtail. The weed seeds are made into proprietary 
cattle foods sold under such names as "germ middlings," "seed meal," 
etc., and are used also as adulterants. 

Examination or Screenings axd Products of Screenings. 

Samples of unground screenings may be separated into their con- 
stituents by sifting and careful sorting. The individual seeds are best 
identified with the aid of a standard collection (see p. 11). 

Microscopic examination coupled with determinations of the proxi- 
mate constituents is sufficient for the identification of mill products of 
screenings, and also for the detection of weed seeds in various cereal 
products, spices, etc. 

Seeds of graminaceous and polygonaceous weeds are described with 
the cereals (pp. 1 18-132) and buckwheats (pp. 138-144). The following 
belong to other families. 


( Caryophyllacece) . 


One of the chief impurities in European grain is the seed of cockle 
(Agrostemma Githago L.). This seed is also found in American wheat, 
but in smaller amount than the fruit of black bindweed, green foxtail, 
and yellow foxtail. 

The black or dark-brown campylotropous seeds are globular-kidnev- 
shaped, resembling a rolled-up caterpillar (Fig. 117). Rows of stout 
warts arranged in semicircular lines about the hilum are evident even to 
the naked eye and especially to the sense of touch. The long, yellow- 
green embryo forms a ring about the pure white, mealy endosperm. 

Cockle is an especially undesirable impurity in grain, as it contains 
a poisonous principle known as "sapotoxin." 




Spermoderm. 1. Outer Epidermis (Fig. 118, 0; Fig. 119). Highly 
characteristic of cockle are the large, more or less elongated (up to 600 fi 

Fig. 117. Cocide {Agvo- 
stemma Githago). 
Seed, enlarged. 


Fig. 118. Cockle. Cross section of outer portion of seed. 
Spermoderm consists of o outer epidermis, p parenchyma, 
and e inner epidermis ; E endosperm consists of thin-walled 
cells containing st starch aggregates. X160. (Moeller.) 

long) epidermal cells, with enormously thickened, deeply sinuous, brown 
walls. These cells form humps, covered on the outer surface with numer- 

FlG. 119. Cockle. Outer epidermis of spermoderm in surface view. X160. (Moeller.) 

ous fine warts. They contain a brown substance which is not removed 
by dilute alkali even on boiling. 

2. Parenchyma (Figs. 118 and 120, p). Beneath the epidermis are 
one or more layers of parenchyma cells with somewhat thickened, brown 



walls. These, like the cells of the epidermis, are more or less transversely 

3. Reticulated Cells (e). A layer of colorless, isodiametric polygonal 
cells with delicate reticulations adjoins the endosperm. Some authors 

Fig. 120. Cockle. Inner layers of spermoderm in surface view, p parenchyma; e inner 
epidermis. X 1 60. (Moeller.) 

describe this layer as the inner epidermis of the spermoderm; Vogl, 
however, regards it as perisperm. 

Endosperm (Fig. 118, E). The large cells contain highly character- 
istic, oval-fusiform, club-shaped, or, less often, globular bodies 20-100 p 
in diameter, composed of minute (scarcely measurable) starch grains. 
These starch bodies slowly disintegrate in cold water, the liberated grains 
displaying lively molecular movements. 

The Embryo contains aleurone grains of considerable size. 


The epidermal layer often occurs as pieces of considerable size in 
bran and similar coarse products. If examined under a lens or held 


with a needle and scraped with a scalpel, the rough surface (Fig. 117) 
is very evident. Under the microscope, a glance suffices for the identi- 
fication of this remarkable tissue (Fig. 119). The coloring matter is little 
acted on by alkali. Equally striking are the starch masses (Fig. 118, si) 
of the endosperm'. 


See General Bibliography, pp. 671-674: Bohmer (6, 10, 23); Hanausek, T. F. (16); 
Harz (18); Mace" (26); Moeller (29); Schimper (37); Tschirch u. Oesterle (40); 
Villiers et Collin (42); Vogl (45); Wittmack (10). 
Benecke: Ueber den Nachweis des Samens der Kornrade (Agrostemma Githago L.) 

in Mahlprodukten. Landw. Vers.-Stat. 31, 407. 
Kruskal: Ueber Agrostemma Githago. Arb. d. pharmakol. Inst. Dorpat. 1891, 6, 

116. , 

Lehmann: Arch. Hyg. 1893, 19, 104. 
Meyer, A. : Mikroskopischer Nachweis von Radenmehl in Getreidemehlen. Han- 

noversche Monatsschrift "Wider die Nahrungsfalscher," 1880, Heft X. 
Petermann: Sur la presence des graines de Lychnis Githago (nielle) dans les farines. 

Ann. chim. phys. i88o> 19, 243. 


The globular seeds of Vaccaria parviflora Moench (Saponaria Vac- 
caria L.) are a common impurity of European wheat. 

In general structure they resemble cockle, but are distinguished by 
the more uniform height of the epidermal cells (Fig. 121) and especially 
by the absence of papilla; on these cells. 


See General Bibliography, pp. 671-674: Villiers et Collin (42); Vogl (45). 


Soapwort, or bouncing bet {Saponaria officinalis L.), a common road- 
side weed with a handsome flower, has a roughened, dark brown seed 
smalle. than cockle (1-1.5 mm.), but closely resembling it in other re- 

The wavy epidermal cells are not warty. 


Harz: Samenkunde, p. 1081. 




The seeds of common spurrey (Spergula arvensis L.) often occur in 
linseed-cake and other concentrated feeds. 

Fig. 121. Cow Herb (Vaccaria parviflora). Outer epidermis of spermoderm in surface 

view. (Moellee.) 

They are 1-1.5 mm - broad, circular in outline, and slightly flattened. 
The seed itself is dark brown, but is encircled 
by a narrow wing of a straw color. 

This seed is readily identified under the 

microscope by the curious club-shaped, warty 

bodies on the outer surface, which are but 

Fig. 122. Spurrey (Sper- modified epidermal cells (Fig. 123). The other 

uS^rtnk^ntget. epidermal cells are sinuous in outline like those 

(Nobee.) f cockle and many other seeds of the same 

family (Fig. 124). 

See General Bibliography, pp. 671-674: Bohmer (23); Harz (18). 



This family includes a number of weeds, the seeds of which are par- 
ticularly objectionable ingredients of grain because of their poisonous 


Nearly all the representatives of the family have flowers with several 
or many pistils ripening either into single-seeded achenes or several- 
seeded pods. 

Fig. 123. Spurrey. Cross section of seed show- Fig. 124. Spurrey. Epidermis of 

ing e outer epidermis of spermoderm with p out- spermoderm in surface view. (Col- 

growths from the centers of the. cells. (Col- LIN and Pereot.) 
lin and Peerot.) 

The brief descriptions which follow are based on Senft's valuable 
paper, to which the reader is referred for further details. 


Senft: Die Bestandtheile des Ausreuters aus der Familie der Ranunculaceen. Pharm. 
Praxis. 1902, 1, 65. 


Of the several species of Ranunculus infesting cultivated fields, the 
fruit of only one (R. arvensis L.) is here described, although those of 
the 'other species are very similar in microscopic structure. 

The achenes (Fig. 125) are 5-6 mm. long, 1 mm. thick, keeled, and 
have a blunt beak and tapering base. On the flattened inner side 
they are prickly. 

Fruits of other species are shown in Fig. 126. 


The Pericarp consists of four layers: (1) The epicarp of yellow-brown 
cells extended into papillae; (2) parenchyma forming a single layer of 
tangentially elongated cells of a yellow-brown color; (3) crystal cells 
(100 ,u) with dark-brown walls; (4) sclerenchyma fibers for the most 
part longitudinally extended in the outer, transversely in the inner layers. 



Spermodenn. (i) The outer layer has detached, rounded, trans- 
versely elongated, thick- walled cells; (2) the inner layer, longitudinally 
elongated, closely united cells with porous walls. 

Perisperm. This consists of more or less quadri- 
lateral cells with thick, porous walls and granular 

Endosperm. The cells are thick walled (up to 
9 fi) and contain aleurone grains embedded in fat. 


See General Bibliography, pp. 671-674: Harz (18); Villiers 
et Collin (42). Also see Senft, loc. cit. 


Fig. 125. Field But- 
tercup {Ranunculus 
arvensis). Seed, nat- 
ural size and en- 
larged. (NOBBE.) if. cat' .,._ 

The compound fruits of Adorns aestivalis L. and 
A. Flammea L. consist of numerous one-seeded, beaked achenes. 

The Pericarp tissues are: (1) an epicarp made up of polygonal cells 
with striated cuticle and stomata; (2) a parenchyma tissue of several 
obliterated layers containing small oxalate crystal clusters; (3) an outer 
endocarp of several layers of large, strongly thickened sclerenchyma 
cells, many of which contain crystals; and (4) an inner layer of trans- 
versely elongated fibers. 


Fig. 126. Buttercup Seeds. I, Ranunculus re pens; II, R. acris; III, R. sceleratus. Nat- 
ural size and enlarged. (Nobbe.) 

Spermodenn. Of the three layers, the middle layer, with porous, 
distinctly striated, yellow walls, is alone worthy of mention. 
The Endosperm contains aleurone grains up to 14 /i long. 


See General Bibliography, pp. 671-674: Harz (18); Villiers et Collin (42). Also 
see Senft, loc. cit. 




The characteristic tissues of the field larkspur {Delphinium Con- 
solida L.) are the outer epidermis and third 
layer of the spermoderm. ^■xgifi, 'BaS^ JF/\^| 

The outer epidermal cells have strongly '* MV ****- «»»'-"* ' ' J 
thickened outer walls with minute warts. 
Curious fan-like outgrowths of this layer 
are highly characteristic. The third layer F IG - I2 7- Field Larkspur {Del- 

. ..... , , phinium Consolida). Seed, nat- 

1S 01 longitudinally elongated, narrow, re- ural size and enlarged; also 
ticulated cells. longitudinal section showing the 

embryo. (Nobbe.) 
The macroscopic characters are shown 

in Fig. 127. 


See General Bibliography, pp. 671-674: Harz (18); Planchon et Collin (34); Villiers 
et Collin (42) ; Vogl (44). Also see Senft, loc. cit. 


In this species {Delphinium Staphysagria L.) the brown walls of 
the epidermis of the spermoderm are strongly thickened throughout, 

Fig. 128. Louse seed {Delphinium Staphysagria). Outer epidermis of spermoderm in 

cross section. (Moeller.) 

and are marked by beautifully distinct concentric rings. The outgrowths 
on the cuticle are here finger-shaped, up to 9 p broad and 30 fi long (Fig. 




The seeds of Nigella arvensis L. are irregularly triangular, flattened, 
about 2 mm. long and 1.2 mm. broad. On the surface they are finely 

The characteristic elements as seen in surface view are the large 

Fig. 129. Black Caraway (Nigetta arven- Fig. 130. Black Caraway. Spiral cells of 
sis). Outer epidermis of spermoderm in spermoderm in surface view. (Moellee.) 

surface view. (Moeller.) 

fioo n broad) papillae-like, dark-brown epidermal cells (Fig. 129) and 
the 4-5 sided striated, cross-cells of the third layer (Fig. 130). 


See General Bibliography, pp. 671-674: Harz (18); Planchon et Collin (34); 
Vogl (44). Also see Senft, loc. oil. 


In many regions cow-wheat (Melampyrum arvense L. order Scro- 
phulariacece) is an abundant wecu, and its seed finds its way into grain. 
The brown, oval seed (Fig. 131) is somewhat smaller than wheat and 
contains a horny endosperm, in the axis of which is embedded the minute 



Only traces of the spermoderm are present, the bulk of the seed con- 
sisting of thick- walled endosperm (Figs. 132 and 133). The cells in the 
outer layer are radially elongated, elsewhere isodiametric, usually about 

Fig. 131. Cow 
Wheat (Mhlampy- 
r um a rvense). 
Seed, natural size 
and enlarged. 

Fig. 132. Cow Wheat. Cross 
section of spermoderm (oblit- 
erated cells) and endosperm. 
X160. (Moeller.) 

Fig. 133. Cow Wheat. Outer 
layer of endosperm in sur- 
face view. X160. (Moel- 

50 ji in diameter. The double walls are 15 /x thick, and, excepting the 
outer and radial walls of the outer layer, are pierced by distinct pores. 
Oil globules and finely granular protoplasm are the only visible con- 


See General Bibliography, pp. 671-674: Bohmer (6, 23); Hanausek, T. F. (16); 
Mace" (26); Moeller (29); Schimper (37); Vogl (43, 45); Wiltmack (10). 
Tschirch: Entwicklungsgeschichtliche Studien. Schw. Woch. Chem. Pharm. 1897, 
35, No. 17. 


In some regions the wild morning glory or field bindweed (Convol- 
vulus arvensis L. order Convolvulacem) is a serious pest in grain fields, 
the vines twining on the grain stalks, thus checking their growth and 
the seeds finding their way into the threshed grain. 

The black seed is the shape of an orange segment, about 4 mm. 
long and 2.5 mm. broad (Fig. 134). It consists of a shell-like spermo- 
derm, a bulky endosperm, and an embryo with curiously folded coty- 




Spermoderm. Cross-sections and surface mounts, the latter prepared 
after boiling the seed in i\ per cent alkali, serve for the study of the 
seed coats. 

i . Outer Epidermis. The cells are of unequal height, the outer walls 
often being convex, forming short papillae. In surface view they are 
polygonal and show dark-brown contents. 

2. Cross Cells. Exceedingly narrow, colorless cross cells arranged 
side by side in rows and often parqueted make up a thin subepidermal 

3. The Palisade Cells forming the third layer are about 75 fi high, 
and are of a yellow-brown color except for a light line about 15 ft from the 

Fig. 134. Bindweed (Convolvulus arven- 
sis). a fruit; b seed, natural size; cseed, 
enlarged. (Nobbe.) 

Fig. 135. Wild Carrot (Daitcus Carota). a 
fruit showing inner or commissural surface, 
enlarged; b showing outer surface, enlarged; 
c fruit, natural size. (Nobbe.) 

outer end. The narrow lumen broadens somewhat near the light line. 
These cells resemble the palisade cells of cottonseed. 

4. Parenchyma Cells form the inner layers of the spermoderm. 

Endosperm. The cells have very thick, more or less mucilaginous 


The epidermal cells with brown contents, the narrow cross cells, and 
the palisade cells serve for the identification of this seed in powder form. 


See General Bibliography, pp. 671-674: Harz (18); Villiers et Collin (42). 


The fruit of the wild form of Daucus Carota L. (order Umbellijera;) 
is broadly ovoid, 1.5-2.5 mm. long (Fig. 135). The secondary ribs are 



barbed with bristles over i mm. long, while the inconspicuous main 
ribs are sparingly hairy. The bristles are made up of numerous axially 
arranged, narrow, elongated cells. Oil ducts are present only in the 
secondary ribs. 

See General Bibliography, pp. 671-674: Harz (18). 


According to Vogl, Bijora radians M. B. (order Umbellifem) is an 
abundant weed in Austrian grain fields, particularly in the region south 
of Vienna, and the fruit frequently occurs in considerable amount in screen- 
ings. In one sample of screenings he found 4.9 per cent of this fruit. 

The pericarp lacks conspicuous ribs and has no oil ducts whatever. 


Pericarp (Fig. 136) 
tinctive characters. 

1. The Epicarp (I, Ep) is smooth, without dis- 

Fig. 136. Hollow Seed {Bijora radians). I pericarp in surface view showing Ep epicarp, 
p parenchyma, Q cross cells, and P reticulated cells (endocarp); II stone cells from 
sclerenchyma iayer of pericarp, isolated bf maceration; III endosperm showing aleu- 
rone grains; IV aleurone grains containing calcium oxalate rosettes. (Vogl.) 

2. The Mesocarp consists of a dense sclerenchyma zone between outer 
and inner multicellular parenchyma layers (p). Many of the scleren- 



chyma cells after maceration display characteristic side branches (//)• 
Curious netted cells form the innermost layer of the mesocarp. 

3. The Endocarp consists of narrow cross cells (Q). 

The Spermoderm lacks distinctive elements. 

The Endosperm (III) contains aleurone grains with conspicuous 
rosettes of calcium oxalate (IV). 

See General Bibliography, pp. 671-674: Vogl (45). 


European grain fields are often infested with the plants of the corn- 
flower (Centaurea Cyanus L. order Composites). 

The achene is light gray, about 4 mm. long, and bears a pappus of 
tan-colored bristles, also about 4 mm. long (Fig. 137). 


The Pappus bristles are made up of bundles of narrow, sclerenchyma 
fibers, some of which are prolonged into upwardly directed barbs. 
Pericarp and Spermoderm are united, forming a leathery hull. 


Fig. 137. Cornflower (Centaurea Cyanus). 
a fruit, natural size; b fruit, enlarged; c 
pappus bristle, enlarged. (Nobbe.) 

Fig. 138. Cleavers (Galium Aparine). 
Fruit, natural size and enlarged. 

i. Epicarp. The cells have thick, porous, sclerenchyma walls, and 
are arranged end to end in longitudinal rows. 

2. Sclerenchyma Cells, similar to those of the epicarp but of smaller 
diameter, form several layers. 


3. Crystal Cells. Beautiful bar-shaped, monoclinic crystals are present 
in great numbers in an ill-defined layer on the inner surface of the scleren- 
chyma coat. After boiling the seed with i\ per cent alkali, this together 
with the first two layers may be readily stripped off from the seed. 

4. The Palisade Cells of the fourth layer are about 75 // high and 
have thick brown walls. They separate from one another on maceration 
in alkali. • 

5. Parenchyma. The several layers of compressed cells, on treatment 
of sections with Javelle water, expand to their normal size. Through this 
tissue passes the raphe. 

The Endosperm consists of a single layer of aleurone cells. 

Embryo. The aleurone grains are exceedingly interesting because 
of their warty outer surface. They are globular or ellipsoidal, varying 
to 18 [i in length, and inclose numerous globoids. 


The elements of value in diagnosis are the upwardly barbed bristles, 
the sclerenchyma layer with crystal cells on the inner surface, the palisade 
cells, and the warty aleurone grains of the embryo. 

See General Bibliography, pp. 671-674: Harz (p8); Villiers et Collin (42). 


A number of plants of the genus Galium (order Rubiacem), known as 
cleavers, bed-straws, etc., are characterized by their slender square stems 
provided with numerous small prickles. The fruit-of G. Aparine L. is 
rounded, 2-3 mm. in diameter, and hollow with a small hole on one side 
connecting with the inner cavity. The surface is roughened with minute 
hooked hairs (Fig. 138). The thin pericarp and spermoderm inclose a 
horny endosperm in which is embedded a crescent-shaped embryo. Other 
species of the same genus have similar fruits, although in some species 
they are of smaller size and without prickles. 


Pericarp (Fig. 139). On boiling with x\ per cent alkali, the pericarp 
readily separates as a gray skin. 



i. TAe Epicarp is highly characteristic owing to warts (2T), the stomata, 
and the large hairs, each with a broadly conical base and a hooked apex. 

2. Mesocarp. A thin-walled tissue, for the most part of spongy 
parenchyma, forms the thin mesocarp. Fibro-vascular bundles ramify 

Fig. 139. Cleavers. 7 cross section of fruit. The pericarp consists of Ep epicarp, P 
mesocarp with R raphides cells, and Q cross cells or endocarp; 5 spermoderm; N 
endosperm. II surface view showing cross cells and spiral vessels. 777 sclerenchy- 
matized parenchyma from mesocarp. IV papilla from epicarp. V spermoderm in 
surface view. VI, Q cross cells in cross section; s isolated raphides cells. (VOGL.) 

through this tissue. Cells containing large raphides bundles occur here 
and there (s). m 

3. The Endocarp Cells are thin-walled, narrow, and transversely 
elongated (27). 

Spermoderm. A single layer of large, polygonal, often elongated cells 


with conspicuous brown walls constitutes this coat (V). Vogl has noted 
the presence of brown starch-grains 3 fi in diameter. 

Endosperm. The exceedingly thick, horny cell-walls of this tissue are 
very striking. 


The warty epicarp cells, the hooked hairs, the raphides bundles, the 
large brown cells of the spermoderm and the horny endosperm are the 
characteristic elements (Fig. 139). 


See General Bibliography, pp. 671-674: Villiers et Collin (42); Vogl (45). 


The minute seeds of common plantain (Plantago major L. order 
Plantaginacea) and the larger seeds of ribgrass or English plantain (P. 
lanceolata L.) are ■ often present as an impurity in flaxseed and other 

Fig. 140. Plantain {Plantago major), a fruit with calyx, 6 fruit with cap, and c longi- 
tudinal section of fruit showing placenta, natural size, d seed from inner side and e 
seed from dorsal side, enlarged. (Nobbe.) 

economic seeds. The brown seeds resemble in form the wheat kernel, 
being elongated, convex on one side and grooved on the other (Fig. 140). 
The characteristic tissue is the thick-walled, porous endosperm, 
reminding us of the endosperm of cow-wheat (Melampyrum}. 

See General Bibliography, pp. 671-674: Bohmer (23). 



Ergot is the resting stage (sclerolium) of Claviceps purpurea Tulasne, 
a fungus belonging to the order Pyrenomycetes. It is formed in the 
inflorescence of rye and other grasses, entirely replacing the grain. 

Ergot is separated from rye for use as a drug in Russia and other con- 
tinental countries. If the grain is not thoroughly freed from this impurity 
it is liable to cause certain diseases, although the opinion of authorities 
differ as to the amount whMi can be eaten with impunity. 

The active stage (sphacelia) of the fungus makes its appearance on 
the ovary during flowering as a soft felt of threads (mycelium), bearing 
numerous brood cells (gonidia) in a slimy mass. Later the mycelium at 
the base of the sphacelia forms a compact mass which develops when 
mature into the elongated sclerotium. At its apex the sclerotium bears an 
easily detachable cap, consisting of the remnants of the sphacelia of the 
fungus and the ovary of the grass. 

The grains of ergot are 1-3 cm. long 1-6 mm. broad, more or less 
angular, longitudinally striate, slightly bowed, tapering toward the blunt 
ends. (Fig. 141.) They are purple-black on the surface, and white 
with a tinge of pink or purple within. 


The structure, although quite simple, is very different from that of 
the cereals. As may be seen in cross-sections mounted in turpentine, 
the compacted hyphse form a false parenchyma, with narrow cells, rounded 
cavities and rather thick walls (Fig. 142). The variation in size of the 
cells is especially noticeable. Fat and proteid matter fill the cells ; starch 
is absent. In one or more of the outer layers both the walls and the cell- 
contents are of a dark brown color, changing to bright red with acids 
and to purple with alkali. 





The cells of the false parenchyma are distinguished from those of 
endosperm tissues by their smaller size and the absence of starch; frorn 
those of germ tissues by their thicker walls, more variable size and irregular 
arrangement. The dark brown coloring matter of the outer layers, with 

Fig. 141. Ergot (Claviceps purpurea), 
with cap. Natural size. (Vogl.) 

Fig. 142. Ergot. Cross section after 
extraction of fat. X 300. (Moeller.) 

the reactions noted above, is characteristic, 
alcohol test is described on p. 52. 

Vogl's hydrochloric aci'd- 


See General Bibliography, pp. 671-674: Berg (3); Bohmer (6, 23); Flvickiger (11); 
Greenish (14); Hanausek, T. F. (16); Mace (26); Meyer (27); Moeller (29, 30, 31, 32); 
Planchon et Collin (34); Tschirch u. Oesterle (40); Villiers et Collin (42); Vogl (43, 
44, 45); Wigand (46); Wittmack (10). 
Belztjng: Journ. pharm. chim. 1890. 
Getiber: Die Methoden d. Nachw. v. Mutterkorn im Mehl u. Brot. Arch. f. Hyg. 

1895, 24, 228. 
Hartwich: Schweiz. Woch. Chem. Pharm. 1893. 

Lagerhetm: Pavisande af mjoldrvga i mjol. Svensk kemisk Tidsk. 1900. 
Mitlacher: Versuch einer quantitativen Bestimmung des Mutterkorns im Mehle. 

Ztschr. allg. osterr. Apoth.-Ver. 1902. 
Moeller: Gutachten in der Mutterkornfrage. Ztschr. Nahr.-Unters. Hyg. 1895. 
Mtjsset: Zum Nachweis von Mutterkorn in Mehl. Pharm. Centralh. 1899. 
Spaeth: Pharm. Centralh. 1896, 17, 542. 



The smuts (Uslilaginece) are parasitic fungi living inside various 
parts of higher plants. Those which infest grain ripen their resting spores 
in the ovaries where they form a dark powdery mass replacing the starch 
of the seed. These spores are more or less globular and have a thick 
membrane or episporium which is smooth or reticulated, brown or color- 
less, according to the species (Fig. 143). 

The Stinking Smuts of Wheat ripen their spores in the wheat kernel, 
destroying the inner tissues but not the outer hull. The damaged kernels 
are not greatly different in size from the sound ones, and consequently 
are not readily separated by screening. Flour made from this grain is 
contaminated with the spores which, if present in appreciable amount, 
injure its color and impart to it a disagreeable odor and taste. 

The common species (Tilletia Tritici (Bjerk) Wint, T. Caries Tul.) 
has reticulated, pale brown, transparent spores reaching 18 y. in diameter 

Fig. 143. Spores of Smuts, a reticulated-spored stinking smut of wheat (^Tilletia Caries); 
b smooth-spored stinking smut of wheat (T. Icevis); c rye stalk smut (Urocyslis occulta); 
d maize smut {Ustilago Maidis); e loose smut (Ustilago Carbo). (Mez.) 

(a); a less common species (T. foetens (B. & C.) Trel., T. laevis Kiihn) 
has smooth spores (b). 

Rye Smut {Tilletia Secalis Kiihn) is a rarer species, occurring chiefly 
in Europe. The reticulated spores are 20-25 p. in diameter. 

Loose Smuts. Several species of loose smuts, formerly classed together 
as Ustilago Carbo Tul., attack the fruit of wheat, oats and barley. As they 
destroy, not only the starchy inner portion of the kernels, but also the hull, 
the spores (e), which vary up to 8 //, escape during harvesting and seldom 
contaminate the grain or the flour made from the grain. 

The following species, infesting respectively wheat, oats and barley, 
have been described: U. Tritici (Pers) Jens, U. Arena (Pers) Jens, 
U. nuda (Jens) Kell. & Sw. 

Maize Smut (U. Zea (Bechm.) Ung., U. Maidis LeV.) develops in 

SMUTS. . 167 

the ear of maize, forming an irregular sack filled with a dust consisting 
of dark brown spores (d), 8-14 n in diameter, with numerous papillae on 
ihe surface. 


Clinton: North American Ustilagineae. Jour. Mycol. 1902, 8, 128. 



All fruits and seed in which the reserve materiatl is largely in the.form 
of oil or fat properly belong under this head, although for convenience 
the cocoanut and other oleaginous nuts are described in Part V, and 
the peanut, which contains starch as well as oil, with other legumes in 
Part IV. The mustards are not only oil seeds but also spices. 

As a rule the oil is contained largely in the embryo, but in the linseed 
it is about equally divided between the endosperm and the embryo, while 
in the olive it is largely in the pericarp. In addition to oil the seeds con- 
tain large amounts of proteins in the form of aleurone grains. 

Oil-seed Products. 

The most important products of the oil seeds are the expressed oils, 
but many of the cakes or residues of the oil presses, like the by-products 
of flour mills, starch factories, breweries and distilleries, are of great 
value as cattle foods. Castor pomace is utilized as a nitrogeneous fer- 
tilizer, and ground cottonseed cake or cottonseed meal both as a cattle 
food and a fertilizer. Mustard cake is employed both as a drug and a 

Some seeds are decorticated before expressing the oil, others are 
pressed whole and the hulls are either separated from the cake after 
grinding, as for example in the manufacture of mustard flour, or are 
not separated at all. 

Since oil cakes and oil meals are rich in protein and also in fat, not- 
withstanding the removal of the larger part of this latter constituent, 
they are known as concentrated feeds. 

Starch being entirely absent in true oil seeds when fully ripe, its pres- 



ence in the cake indicates adulteration with starchy material or at least 
contamination with weed seeds. Peanut cake, however, being a by-product 
of a starchy legume, contains a considerable amount of starch, while on the 
other hand, maize cake, although a cereal product, is free from starch. 

The hulls separated from cottonseed, sunflower seed and some other 
seeds are utilized as adulterants of cattle foods, and mustard hulls are 
employed as adulterants of spices and prepared mustard. 

The dried residues from the manufacture of some of the essential 
oils are also non-starchy materials similar to those here considered. 

Methods of Examination. 

pre limin ary Examination. Each oil-cake has certain physical char- 
acteristics, such as color, odor, texture, deportment with water, etc., 
which can be learned only by experience. For example, maize cake 
has a characteristic taste and odor; cottonseed cake a characteristic color; 
most cruciferous products develop an odor of mustard oil on mixing 
with water; linseed cake becomes slimy by the same treatment; and so 

Foreign seeds, fragments of hulls and other constituents may often 
be found by macroscopic examination of the unground material or of 
the coarser grades obtained by sifting. These, if not identified by the 
naked eye or under the lens, are reserved for microscopic examination. 

Cold-water Test. The presence of a large excess of hulls in cotton- 
seed meal is easily disclosed by mixing 5 grams of the ground material 
with 100 cc. of cold water, and comparing the deposit of black hulls, 
which immediately settles from the yellow suspended matter, with that 
obtained by the same method from samples of known composition. 

This simple process is also useful in the examination of other oil cakes 
as well as some cereal products, and serves not only to detect hulls but 
also added mineral matter. 

Collin and Perrot's Method 1 of preliminary examination is as follows: 
Boil 2 grams of the powdered material 10 minutes with 60 cc. of water 
to which are added 10-12 drops of concentrated potash solution. Allow 
to settle 7 or 8 minutes, decant and wash twice with water by decanta- 
tion. The last decantation should leave 1,5-20 cc. of water in the dish, 
which, given a gentle gyratory motion causes the particles of the residue 

1 Les Residus Industriels, etc. Paris, 1904, 35. 


to deposit according to their density. These particles are examined 
as to their physical properties, especially their color and hardness, and 
are afterwards prepared for microscopic examination. 

Chemical Analysis. Tests for starch or starchy adulterants are 
made by boiling a small quantity of the material with water, cooling and 
adding a few drops of potassium iodide iodine. 

Quantitative determinations of starch are laborious and only neces- 
sary in exceptional cases, but determinations of protein (Nx6|), fat 
and crude fiber are easily made and are essential for the proper valuation 
of the material. The addition of starchy substances tends to diminish 
the percentage of protein and fat without greatly altering the percentage 
of crude fiber, while the addition of hulls or woody adulterants tends to 
increase the percentage of fiber at the expense of both the protein and 

Microscopic Examination. Starch grains being absent, except in 
peanut cake and in cake made from unripe or impure seeds, the micro- 
scopist must rely largely on the structure of the hulls, or in exceptional 
cases on the characters of the aleurone grains. The treatment pre- 
liminary to the microscopic examination is also very different from that 
employed for starchy products. Digestion with diastase or boiling with 
dilute acid is obviously irrational in products containing no starch, but 
on the other hand, extraction with ether or a similar solvent is often neces- 
sary owing to the presence of considerable fat, and treatment with alkali 
to remove the proteid matter is usually desirable. 

Direct Examination of the powdered material in water is useful chiefly 
in detecting foreign matter containing starch. As starch grains are 
liable to be confused with oil drops and proteid grains, addition of 
iodine tincture is advisable. 

Addition of alkali facilitates the examination of the tissue by dis- 
solving the proteid grains, saponifying or emulsifying the oil, and swell- 
ing the cell-walls. Mounting in a drop of concentrated sulphuric acid 
aids in identifying cottonseed meal, as the resin masses become bright 
red in this reagent. 

Chloral hydrate serves to detect the hulls of wild mustard by im- 
parting a beautiful cherry-red color to the contents of the palisade cells. 
These and a few other reactions are of value in diagnosis, but as a rule 
reagents serve merely to clear the tissues, thus facilitating their examina- 

Fragments of the hulls picked out from the unground material 


are sectioned, scraped, macerated or otherwise treated and examined 
in water, dilute alkali or some other suitable medium. 

Ether Extraction preliminary to examination in water or to treatment 
by Hebebrand's method may be performed on a filter or by decantation 
in a beaker. If more complete extraction is desirable the continuous 
apparatus of Soxhlet, Tollens or Johnson may be employed. 

Hebebrand's Method * for clearing sesame cake and other materials 
with delicate tissues which would be destroyed by Beneke's methods is 
as follows : 

Extract a portion of the material with ether and grind so as to pass 
a 0.5 mm. mesh. Mix 0.5 gram of the extracted and finely ground 
material with 10-15 cc. of sodium carbonate solution (7 grams of the dry 
salt in 100 cc. of water) and pass chlorine gas into the mixture, taking 
care that the solution remains alkaline. After 2-15 minutes, according 
to the material, dilute with water, allow the fragments of tissues to settle, 
decant off the liquid and wash twice by decantation. Examine the residue 
in water or some other suitable solvent. 

Chlorine gas is conveniently prepared by treating the so-called "chlo- 
ride of lime cubes" with dilute hydrochloric acid in the special form of 
generator supplied by Peters and Rost, Berlin. Sufficient gas for clearing 
one sample may be generated from a single cube. 

Beneke's Method 2 may be used for accumulating and clearing tissues 
of the pericarp and spermoderm, provided these tissues are strongly devel- 
oped. It is not suited for clearing delicate tissues. 

It is described at some length by the author, but the following direc- 
tions will be found sufficient: Heat in a porcelain dish, with constant 
stirring, about 5 grams of the material with 30 cc. of concentrated 
hydrochloric acid and 10 cc. of concentrated nitric acid until the liquid 
begins to foam. Add at once considerable cold water, and filter on a 
piece of fine mull and wash with water. 

Rinse back into the dish with 60 cc. of water, add 30 cc. of concentrated 
sodium hydrate and heat until the solution begins to boil. Dilute with 
cold water, filter and wash as before. Mount the residue and examine. 

Collin and Perrot's Method. See p. 170. 

1 Beitrag zur mikroskopischen Untersuchung von Nahrungs- u. Futtermitteln. For- 
schungsber. f. Lebensm. 1897, 306. Landw. Vers.-Stat. 1808, 51, 74. 

2 Anleitung zur mikroskopischen Untersuchung der Kraftfuttermittel. Berlin, 1886, 38. 



The flowers of cruciferous plants are very similar in all the species, 
having, as the family name suggests, four regular petals and four sepals. 
Classification is based largely on the characters of the pods and seeds. 

The pods, known as siliques when long or silicles when short, are com- 
monly divided into two cells by thin, longitudinal partitions, passing through 
the two parietal placentae. When ripe the outer walls of each pod separate 
from the partition as two valves, the seeds remaining with the partition. 

The campylotropous seeds consist largely of spermoderm and em- 
bryo with a thin endosperm, and usually have a pungent taste. 

As seen in cross section the arrangement of the cotyledons (=) with 
reference to the radicle (o) may be accumbent (0 = ) incumbent (o||) 
or conduplicate (o >>). In some species the cotyledons are coiled or 
folded endwise, the cross section appearing thus: o |( |j, o || | j | etc. 

Under a lens the seeds of some species show numerous shallow pits, 
the ridges between the pits forming delicate reticulations. 

Microscopic Characters of Cruciferous Seeds. 
The Spermoderm (Figs. 145 and 145a) normally has four layers, but 
in many species the first and second layers at maturity are not distinctly 

1. The Epidermal Cells (ep) when evident are polygonal, and usually 
have thin walls. In certain species on adding water a mucilaginous 
substance is evident which D'Arbaumont, contrary to the formerly accepted 
view, has shown is formed from cell contents, not from the cell-wall. 

D'Arbaumont divides the phenomena observed in numerous species 
on addition of water into four groups : 

(1) Complete diffusion of the contents. 

(2) Diffusion of the lateral layers, an axial cylinder remaining 

(3) Simple swelling of the layers. 

(4) The mucilage, owing to the pressure developed in the cell, bursts 
through the outer wall, forming a body of definite shape. 

These phenomena are of value in diagnosis. As noted by Collins, 
each cell" displays a polarization cross. 

2. The Subepidermal Layer, or outer parenchyma layer, consists of one 

1 Revised by Kate Barber Winton after studying authentic material, including Prain's 
specimens of Indian rapes and mustards kindly furnished by Dr. Arpad de Degen, Director 
of the Royal Hungarian Seed-testing Station, Budapest. 


or two cell layers of thin-walled polygonal elements often of considerable 
size. In some species,, notably white mustard, the cells (Fig. 144, col) 
are collenchymatously thickened at the angles. 

3. The Palisade Cells, or beaker cells, form the most striking layer of 
the seed. The inner walls and at least the inner portions of the radial 
walls are more or less strongly thickened, giving the cells in cross section 
(Fig. 145, pal) a beaker-like appearance. These thickened walls are either 
yellow or brown, according to the color of the seed. 

In certain species this layer in surface view displays dark meshes 
(Fig. 1450, pal 2 ) corresponding to the reticulations of the spermoderm. 
This appearance is due to the greater height of the palisade cells (Fig. 
145, pal) in the meshes and is valuable in diagnosis. 

As seen in surface view the cells vary greatly in breadth (3-100 //) 
and have a sharply polygonal outline and more or less rounded lumen. 
Owing to their polygonal form and thick walls they present a mosaic-like 

4. The Pigment Cells (pig) are in one or more layers and contain, 
in the case of brown seeds, a dark colored material. In surface view 
they lack characteristic features. 

Endosperm. Most authors have described the* remaining layers of 
the hull as inner spermoderm; Gruinard and also Gram, however, have 
demonstrated that they belong to the endosperm. 

1. Aleurone Cells (E) similar to those found in the cereals form the outer 
portion of the endosperm. In most seeds only a single cell layer is present 
except under the micropyle where there are two or even more layers, and 
under the hilum where they are entirely absent. 

2. Obliterated Parenchyma makes up the remainder of the endosperm. 
The Embryo tissues are thin-walled and contain aleurone grains and 


Chief Characters. 

None of the common cruciferous seeds contains starch, and all have 
a palisade layer of beaker cells forming a brown or yellow mosaio, and 
an endosperm with usually a single layer of aleurone cells. 

Of diagnostic value when present are the epidermal cells with muci- 
laginous contents, the subepidermal layer of collenchyma cells and the 
pigment layer. 


Analytical Key to Cruciferous Seeds. 

A. Spermoderm yellow. 

1. Epidermal cells with mucilaginous contents; subepidermal layer collen- 

chymatous White Mustard (Brassica alba). 

2. Epidermal cells with mucilaginous contents; subepidermal layer not evi- 

dent (Eruca sativa). 

3. Epidermal and subepidermal layers form a nearly structureless membrane 

(not distinctly cellular) . .Indian Colza {Brassica campestris var. Sarson). 

B. Spermoderm brown. 

(a) Palisade layer with reticulations. . 

* Epidermis cellular, usually with mucilaginous contents. 

4. Subepidermal cells large, not collenchymatous; palisade cells red-brown, 

narrow (usually 3-10 ju) Black Mustard (B. nigra). 

5. Subepidermal cells collenchymatous; palisade cells red-brown. 

(Sinapis dissccia). 

6. Subepidermal cells very large, collenchymatous; palisade cells red-yellow. 

Wild Radish (Raphanus Raphanistrum). 

7. Subepidermal cells indistinct or lacking; pab'sade cells red-brown, broader 

than in 4 Brown Mustard (B. Besseriana). 

8. Subepidermal layer lacking; palisade cells after treatment with acid and 

alkali, yellow-brown Palai Rape (B. rugosa). 

** Epidermis not distinctly cellular, 
t Palisade cells with lumen broader than double walls. 

9. Reticulations distinct. .Brown Indian Rape (B. Nap'us var. dichotoma). 
ft Palisade cells with lumen narrower' than double walls. 

10. Reticulations distinct Indian Mustard (B.juncea). 

11. Reticulations indistinct German Rape (B. Rapa). 

(b) Palisade layer with ribs, not reticulations. 

12. Epidermal and subepidermal layers not cellular. 

Field Pennycress (Thlaspi arvense). 

(c) Palisade layer without distinct reticulations or ribs. 
* Epidermis cellular with mucilaginous contents. 

t Mucilage escapes as long tapering columns. 

13. Epidermal and palisade cells broad (up to go fi), walls 15-20 y.. 

False Flax (Camelina sativa). 

14. Radial walls of epidermis thick and porous; palisade cells broad with 

broad lumen (Erysimum orientate). 

ft Mucilage escapes as long columns broadened at the outer ends. 

15. Palisade cells up to 40 n Pepper Grass (Lepidium). 

ftt Mucilage in axial columns seldom escaping from the cells. 

16. Palisade cells up to 60 \x broad with broad lumen; epidermal cells in rows. 

Shepherd's Purse (Capsella Bursa-Pastoris). 

17. Palisade cells narrow, thickened at inner ends. . . .(Sisymbrium officinale). 
tftt Mucilage never escapes from cells. 

18. Mucilage in layers in outer portion of cells; palisade cells broad with 

broad lumen, containing an oxalate crystal (Barbarea vulgaris). 




19. Mucilage shows honeycomb structure; palisade cells narrow, contents 
dark, becoming red with acid chloral hydrate. . .Charlock (B. arvensis). 

Epidermis not distinctly cellular. 

20. Palisade cells av. 20 y., lumens av. 10 y. Rape {B. Napus). 


See General Bibliography, pp. 671-674 Bohmer (6, 23); Collin et Perrot (9). 
Abraham: Bau und Entwicklung der Wandverdickungen in den Samenoberhaut- 

zellen einiger Kruziferen. Jahrb. f. wissensch. Bot. 1885, 14, 559. 
d'Arbaumont: Note sur les teguments seminaux de quelques Cruciferes. Bot. Jahresb. 

1890, 18, I Abt., 663. Journ. de m'crographie. 1891, 15, 212. Bull. Soc. Bot. de 

France. 1891, 38, 67. 
Burchard: Ueber den Bau der Samenschale einiger Brassica- und Sinapis-Arten. 

Jour. f. Landw. 1894, 42, 125. 1896, 44, 337. 
Bussard et Fron: Torteaux de graines oleagineuses; examen macroscopique et 

microscopique diagnose. Ann. d. l'inst. nation, agron. 1892-96. No. 15, 117. 
Claes et Thyes : Morphologie comparee des testes des Brassica : oleracea, napus, rapa 

et nigra et des Sinapis: alba et arvensis. Bull, de l'agric. 1891, 7, 253. 
Collins : Mustards and Charlock. Swarthmore, 1910. 
Gram: Ueber Rapskuchen und deren Verunreinigung. Landw. Vers.-Stat. 1898, 50, 

Guignard : Recherches sur le developpement de la graine et en particulier du tegu- 
ment seminal. Jbur. Bot. 1893, 7. 
Hartwich u. Vuillemin: Beitrage zur Kenntnis der Senfsamen. Apoth. Ztg., 1005. 
v. Hohnel: Bau der Samenschale der vier cultivirten Brassicaarten; in Haberiandt: 

Wissensch. -prakt. Untersuch. auf dem Gebiet des Pflanzanbaues. 1875, 1, 171. 
Kinzel: Ueber die Samen einiger Brassica- und Sinapis-Arten, mit besonderer Bertick- 

sichtigung der ostindischen. Landw. Vers.-Stat. 1899, 52, 169. 
Kobus: Kraftf utter und seiner Verfalschung. Landw. Jahrb. 1884, 13, 813. 
Pammel: On the Seeds and Spermoderm of some Cruciferas. Amer. Monthly Mcr. 

Jour. 1897, 1. 
Pieters and Charles: The Seed Coats of Certain Species of the Genus Brassica. U. S. 

Dep. Agr., Div. Bot. Bull. 29, 1901. 
Prain: A Note on the Mustards cultivated in Bengal. Agricultural Ledger 1898, No. 1. 
Schroder: Untersuchung des Samens der Brassica-Arten und Varietaten. Landw. 

Vers.-Stat. 1871, 14, 179. 
Sempolowski: Ueber den Bau der Schale landwirthschaftlich wichtiger Samen. 

Landw. Jahrb. 1874, 3, 823. 
Tschirch: Entwicklungsgeschichtliche Studien. Schw. Woch. Chem. Pharm. 1897, 35, 

No. 17. 
Vuillemin: Beitrage z. Kenntnis der Senfsamen. Diss. Zurich, 1904. 
Wolff: Zur Kentniss der Senfsorten des Handels. Pharm. Ztg. 1893, 38, 761. 




Yellow or white mustard {Brassica alba (L.) Boiss., Sinapis alba L.), 
a native of Europe, is grown for its seed in various parts of Europe and 
America, particularly in England, Holland, Germany, and California. 

The nearly globular seeds are 1.5-2.5 mm. in diameter and are 
usually of a buff color although occasional seeds are black or dark brown. 
Examined under a lens they have an indistinctly reticulated surface. 
Like all .the mustards they are campylotropous. Cross sections slightly 
magnified show the embryo consisting of the radicle and two large con- 
duplicate xotyledons. 

In addition to sinapin sulphocyanide and the enzyme, myrosin, both 
of which are found also in black mustard, white mustard contains a 
glucoside, sinalbin, which, in the presence of water, is split up by myrosin 
into sinapin hydrosulphate, d. extr ose, and sinalbin su'phocyanide, the 
latter being a non-volatile principle with a biting taste. 


Cross sections are cut of the dry seed embedded in hard parafnne' 
or held between pieces of cork. For the study of the epidermis these are 
mounted in alcohol, and water is 
cautiously drawn under the cover- 
glass during observation. The 
same sections, after treatment 
with alkali, serve for the study 
of the other layers of the spermo- 
derm. Sections mounted in tur- 
pentine or strong glycerine are 
adapted for studying the aleurone 
grains of the endosperm and 
embryo. Surface preparations 
of the spermoderm and endo- 
sperm are obtained by heating 
with dilute alkali and scraping 
with a scalpel. 

Spermoderm (Fig. 144, S; 
Fig. 144a). 1. The Epidermis (ep) consists of polygonal, isodiametric 
mucilage cells, ranging up to 115/4 in diameter, with finely beaded 
primary walls. Cautious treatment of alcohol mounts with water dis- 

'Fig. 144. White Mustard {Brassica alba). 
Seed in cross section. 5 spermoderm con- 
sists of ep epidermis, col collenchyma, pal l , 
outer thin-walled portion of palisade layer, 
pal 2 inner thick-walled portion of palisade 
layer, and p parenchyma; E endosperm; 
C cotyledon with aep outer epidermis and al 
aleurone cells. X160. (K. B. Winton.) 

i 7 8 


plays the mucilaginous substance deposited in layers with a distinct cyl- 
indrical cavity in the axis of each cell. In surface view, concentric rings 
and often radial clefts are evident. 

2. Collenchyma {col). Characteristic of white mustard are the sub- 
epidermal cells with collenchymatously thickened angles and triangular 
intercellular spaces. These are of about the size of the epidermal cells 
and are usually in two layers. 

3. Palisade Cells {pal 1 and pal 2 ). Radially elongated cells, thickened 
in the inner half, form the most conspicuous layer of the seed, the 
thickened walls forming a kind of cup, hence the name " beaker cells." 
Of great diagnostic importance are the colorless, thickened walls, which 

Fig. 144a. White Mustard. Elements of seed in surface view. Significance of reference 
letters as in Fig. 144. X160. (K. B. Winton.) 

in most economic cruciferous seeds are brown. As these cells are of 
nearly uniform height, pronounced reticulations are not evident on the 
seed. In surface view the cells are sharply polygonal, varying up to 
22 ji in diameter. 

4. Inner Layers {p). Two or more layers of thin-walled isodiametric 
or elongated cells complete the spermoderm. These cells, unlike the 
corresponding layer of many cruciferous seeds, do not contain a pigment. 

Endosperm (£). 1. Aleurone Cells. These cells resemble closely 
the aleurone cells of cereals. They are 10-40 /( in diameter, have thick, 
colorless walls, and contain fat globules and polygonal or rounded aleurone 
grains 1-4 (i in diameter. 

2. Obliterated Parenchyma. The remainder of the endosperm con- 
sists of compressed cells without evident cellular structure. 

Embryo (C). Cross sections show that not only the cells on the 


inner sides of the cotyledons (the upper sides after sprouting) are typi- 
cal palisade cells, but all the mesophyl cells are more or less elongated. 
These cells in the mature seeds contain fat and aleurone grains, never 
starch. The aleurone grains are either isodiametric - or oblong. In the 
outer epidermis (aep) the isodiametric grains aire about 3 fi in diameter, in 
the inner layers (al) 6-10 /*. The oblong grains are about the same width 
as those of isodiametric form, but are often twice or three times as long. 
As the cells are but little broader than the grains, each usually contains 
but a single row of grains, which are often so crowded that the sides in 
contact are more or less flattened. Each grain contains numerous minute 

As was first noted by Gruinard, occasional cells of both the cotyledons 
and radicle contain grains without globoids, which, in sections previ- 
ously extracted with ether, are colored bright crimson-red on gently 
heating with Millon's reagent and golden-yellow on treatment in the 
cold with iodine. These cells are believed by both Gruinard and Gram to 
be the seat of the myrosin, and are designated "myrosin-cells. " 


The color of white mustard seed serves to distinguish it from all 
black or brown cruciferous seeds both in a macroscopic and microscopic 
way. Seeds of white Indian colza (B. campestris L. var. Sarson Prain) 
sometimes used as an adulterant, although of the same color as white 
mustard, are distinguished macroscopically by the more pronounced 
ridge over the radicle, and microscopically by the indistinct epidermis, 
the absence of a collenchymatous subepidermal layer and the large size 
of the palisade cells. 

White Mustard Flour is prepared either from the whole seeds, or* 
more commonly from the cake remaining after expressing the oil. Al- 
though the hulls are largely removed, fragments are always present in 
small amount and are distinguished from the brown hulls of black 
mustard and other related seeds by their yellow color. The bulk of 
the organized material consists of protein and fat. Examined in tur- 
pentine or, after extraction of the fat, in iodine tincture, the aleurone 
grains are clearly differentiated. White and black mustard flour are 
usually blended, as noted under black mustard. 

Prepared Mustard. See Black Mustard (p. 182). 

White Mustard Hulls, separated in the manufacture of mustard 
flour, serve as an adulterant for prepared mustard and various spices. 


The elements of the hulls of chief value in diagnosis are the colorless 
distinctly cellular epidermal layer (Fig. 144a, ep) with mucilaginous con- 
tents, the collenchymatous subepidermal layer {col) and the yellow mosaic 
of palisade cells {pai 2 ) with indistinct reticulations. 


See General Bibliography, pp. 671-674: Berg (3); Blyth (5); Bohmer (10); Fliick- 
iger (n); Greenish (14); Hanausek T. F. (16, 48); Harz (18); Hassall (19); Leach 
(25); Mace" (26); Meyer, A. (10, 27, 28); Moeller (29, 30, 31, 32); Planchon et Collin 
(34); Schimper (37); Tichimirow (38); Tschirch u. Oesterle (40); Villiers et Collin 
(42); Vogl (43,45)- 

Also see Bibliography, of Cruciferas, p. 176. 
Harz: Ueber eine neue Verfalschung des weissen Senfes. Bot. Centralb. 1887, 8, 249. 
Steffeck: Ein neues Falschungsmittel des weissen Senfes (Sinapis alba). Landw. 
Vers.-Stat. 1887, 33, 411. 


Black mustard (Brassica nigra, (L.) Koch) is cultivated in various 
parts of Europe, Asia, and America. The globular, campylotropous 
seeds (1-1.5 mm var y ln color from light brown to nearly black. 
Under a lens they show fine reticulations averaging about 90 (i in 
diameter. The husk or hull of the seed, consisting of the spermoderm 
and the thin endosperm, envelops the embryo with its conduplicate 

The sharp taste of black mustard is due chiefly to allyl sulphocyanide, 
or volatile mustard oil. This does not, however, exist ready formed in 
the seed, but is developed by the action of an enzyme, myrosin, on a 
glucoside, sinigrin (potassium myronate), in the presence of water. 


Cross sections and surface mounts are prepared as described under 
white mustard. 

Spermoderm (Fig. 145, 5; Fig. 145a). 1. The Epidermis (ep) con- 
sists of large (50-100 /i) polygonal mucilage cells with finely beaded 
primary walls. If sections are first mounted in alcohol, and water is 
carefully drawn under the cover-glass, the mucilaginous substance is seen 
to be deposited in layers. Gentle warming with alkali removes this sub- 
stance, and also aids in clearing the remaining layers. 

2. Subepidermal Layer (sub). Beneath the epidermis are thin-walled 
cells even larger than those of the epidermis, the radial walls of which 



correspond with the reticulations of the seed and the highest cells of 
the next layer. 

3. Palisade Cells (pal). Cross sections show that the brown pali- 
sade or beaker cells are of unequal height, causing the reticulated ap- 
pearance of the seed and the con- ^^^^^^ 
spicuous, dark meshes seen in ^^^^■■!^~~^~''^^S = ^y) 
surface view (Fig. 145a, pal 2 ). sub ''~~^^L i ^^}^f^^^^Trrrr p 
Sometimes the outer thin-walled ~jSg- -^^^^^^^^^^^^^^^^ > 
portion of the palisade layer ' ^^^^^^^^^S }^ 
breaks away from the remainder ae P ~ '^^^^&ffj^JJ^XX^ \c 
of the spermoderm, as shown in f \ AKi J 

Fig. 14^, pal 1 . In surface view, FlG - J j$: Black H ustard „ (Brasska nigra). 

J L _ . seed in cross section. 5 spermoderm con- 

the cells are isodiametric, 4—10 [i, sists of ep epidermis, sub subepidermal layer, 

in rliumptpr nr plnncrarprl rparh pd P aUsade cells > and P*S pigment cells; E 

in diameter, or elongated, reacn- endosperm; C cotyledon with aep outer 

ing a maximum length of 20 a. epidermis and al aleurone cells. X160. 

^ „ / • s X (K. B. WlNTON.) 

4. Pigment Cells (pig). One, 

sometimes two, layers of cells with brown contents form the inner coat 
of the spermoderm. In surface view the cells are either isodiametric or 
somewhat elongated, often reaching a length of 75 fi. Ferric chloride 

^pal 1 P'ff, 


eP X^iy pul 1 ^^' e^Q^xT ~ : 

Fig. 145a. Black Mustard. Elements of seed in surface view. -Significance of reference 
letters as in Fig. 145-. X160. (K. B. Winton.) 

colors the cell-contents blue. The color of the seed is due partly to 
this layer and partly to the palisade layer. 

The Endosperm (E) and Embryo (C) are practically the same as 
described under white mustard. 

Black Mustard Seed is distinguished from that of white mustard by 
its darker color, from brown mustard by its smaller size and finer retic- 


ulations, and fiom rape by its smaller size and distinct reticulations. 
Charlock, a common weed seed, is about the same size, but is not 
reticulated and is usually of a darker color. 

Black Mustard Flour, like that made from white mustard, is usually 
prepared from the cake, with the removal of the hulls. It is a common 
practice to blend the flour of both black and white mustard, the excess 
of myrosin in the latter serving to convert the last traces of potassium 
myronate of the former into allyl sulphocyanide. The flour of black 
mustard consists in large part of embryo substance, with occasional frag- 
ments of the hulls (spermoderm). The aleurone grains may be examined 
in oil of turpentine, or, after the removal of the fat, in strong glycerine. 
Fragments of the spermoderm, owing to their darker color, cannot be 
confounded with those of white mustard. The reticulations are smaller 
than in brown mustard and German rape; charlock and common rape 
have no reticulations. The palisade cells (Fig. 145a, pal 2 ) are smaller 
than those of brown mustard and rape. Charlock, a common adulter- 
ant, is detected by the cherry-red color imparted to fragments of the 
hulls by treatment with acid chloral hydrate (p. 185). Examined with a 
lens the proportion of Charlock can be roughly estimated. 

Other adulterants of mustard flour are wheat flour and other cereal 
products, gypsum and other mineral substances, turmeric and coal-tar 
dyes. Since mustard contains no starch, farinaceous adulterants are 
especially easy of detection. Turmeric is identified by the bright yellow 
particles which change to reddish-brown on treatment with alkali. 

Prepared Mustard. Mustard paste, also known as German or French 
mustard, is a mixture of flour or ground mustard seed from one or more 
kinds of mustard with spices, salt, and vinegar. It is often adulterated 
with charlock, starchy matter, mustard hulls, dyes and preservatives. 
Turmeric being a spice cannot properly be regarded as an adulterant. 

Black Mustard Hulls, obtained as a by-product in the manufacture 
of the flour, are used not only as adulterants of mustard paste, but of 
pepper and other spices. 

The palisade cells are the most striking elements; The inner thick- 
walled portion of the layer forms a brown mosaic (pal 2 ) with darker 
reticulations, while the outer thin-walled portion displays a delicate 
network (pal 1 ). 


See Bibliography of White Mustard, p. 180. 



In Russia the so-called Sarepta mustard (B. Besseriana Andr.) is 
grown in considerable quantities. Formerly this species and Indian 
mustard (asi-rai) were both known as B. juncea Hook. f. et Thorns., 
but Prain has shown that these two - — -^ — ^ ^ _ 

plants are distinct, and has reserved e ^'-'^^^^^^^^^^^^^^^\ S 

out the striking diSerence in the aep — ^^^f^^wn^it^. \C 
histological structure of the two a >% /vVy^t fji ) 

seeds. Macroscopic and micro- Fig. 146. Brown Mustard (Brassica Besse- 
.• <■ riana). Seed in cross section. S spermo- 
scopic examination of numerous derm consists of ep epidermis; sub sub- 
samples Of brown mustard cultivated epidermal layer, pal palisade cells, and 

. pig pigment cells; E endosperm; C cot- 

in both Europe and America, as yledon with aep outer epidermis and al 

well as escaped in American grain aleurone cells. X160. (K. B. Winton.) 

fields, show that the seed is undoubtedly from the Russian and not the 
Indian species, notwithstanding the statements by American authors to the 

Fig. 146a. Brown Mustard. Elements of seed in surface view. Significance of reference 
letters as in Fig. 146. X 160. (K. B. Winton.) 

The seed (1-2 mm.) is somewhat larger than that of black mustard 
and the reticulations are broader and more distinct. 

In microscopic structure (Figs. 146 and 146a) the seed is distinguished 
from black mustard by (1) the mucilage in the epidermal cells which, 
after treatment of alcohol mounts with water, shows concentric rings 
about a central core, (2) the less distinct subepidermal layer, and (3) 
the larger size of the palisade cells and the dentate appearance in cross 

1 84 



See Bibliography of Cruciferae, p. 176: Bohmer; Kinzel; Hartwich u. Vuillemin. 
Tichomirow: Die Struktur der Samenschale von Brassica juncea Hook. Pharm. 
Centralh. 1900, 41, 510. 


Grain fields, both of the Old and New World, are often infested by 
charlock (Brassica arvensis (L.) Ktze., B. Sinapistrum Boiss., Sinapis 

arvensis L.), a cruciferous plant 
S with bright yellow flowers. Char- 
lock is especially abundant in the 
) -® grain fields of the Northwest. So- 
called wild or Dakota mustard con- 
sists of variable mixtures of char- 
lock and brown mustard separated 

F1G.-147. Charlock (Brassica arvensis). m Seed from screenings by ingenious ma- 
in cross section, o spermoderm consists of ° J ° 
ep epidermis, sub subepidermal layer, pal chines depending on the principle 

P dol^mfc'clty\IdL P wk^Lf^tefe^- that the round seeds ro11 awa y from 

dermis and al aleurone cells. 
B. WlNTON.) 

C160. (K. the other seeds on amoving inclined 
belt or disk or in a spiral trough. 
The deep brown or black seeds (1-1.5 mm.) have a dull surface, 
but do not appear reticulated, even under a lens. Charlock yields prac- 
tically no volatile oil. 

Fig. 147a. Charlock. Elements of seed in surface view. Significance of reference letters 
as in Fig. 147. X160. (K. B. Winton.) 

This seed differs from other cruciferous seeds in the structure of the 
mucilaginous substance of the epidermis, and the nature of the contents 
of the palisade cells. 


Spermoderm (Fig. 147, S; Fig. 147a). 1. The Epidermal Cells (ep) 
are 40-75 ft in diameter. Cross sections mounted in alcohol and treated 
cautiously with water display well-defined radial walls and a radially 
striated mucilaginous deposit. This latter, in surface view, is seen to 
be made up of an aggregate of delicate cylinders about a central cavity. 
The cylinders are about the same size as those formed by the outer radial 
walls of the palisade cells, but are not so distinct, and disappear entirely 
on adding sufficient water. Harz first called attention to this structure, 
and Gram shows it clearly in his figures. 

2. Subepidermal Layer (sub). This coat consists of two compressed 
layers of thin-walled cells. 

3. Palisade Cells (pal). The dark contents are highly character- 
istic. Waage« first noted that treatment with chloral hydrate solution 
changes the color to crimson-red. The author finds that this reaction 
takes place only when the reagent is acid, and best after cautious heating. 
Although chloral hydrate solution gradually develops acidity on standing, 
the best procedure is to add at once to 20 c.c. of the usual reagent, 1 c.c. 
of concentrated hydrochloric acid. The reaction also takes place with 
acidified glycerine or zinc chloride solution and with syrupy citric acid 
solution, showing that it is dependent on the acid. The chloral hydrate 
serves merely to penetrate the masses. 

4. Pigment Layer (pig). A single row of pigment cells is present. 
Although the contents are yellowish-brown, the dark color of the seed 
is due solely to the material in the palisade cells. 

Endosperm and Embryo are much the same as in black mustard. 


The dark, nearly black color of the seeds and the absence of retic- 
ulations on the surface distinguish charlock from black and brown mustard; 
the smaller size of the seeds distinguishes it from rape. The delicate 
radial cylinders of the mucilaginous substance in the epidermis are char- 
acteristic, but not always clearly evident. Especially striking are the 
dark contents of the palisade cells, which become blood-red on heating 
cautiously on the slide with acid chloral hydrate. 


See Bibliography of Cruciferae, p. 176: Bohmer; Burchard; Collin et Perrot; 
Collins; Gram; Hartwich u. Vuillemin; Pieters and Charles. 




Of the cruciferous seeds utilized for oil and cattle food, not for con- 
diments, common rape, also known as colza, (Brassica Napus L.) is 
the best known in Europe. Before the advent of petroleum and coal 

gas, rape oil was burned for illuminat- 
ing purposes; but at the present time 
it is used chiefly as a lubricant and for 
making soap. As the cake yields but 
a small amount of volatile oil, it is 
well adapted for feeding animals. 

Rape is grown chiefly in Germany, 

Russia, and Austria-Hungary, to a 

limited extent in France and Belgium, 

but seldom in America. There are 

summer and winter varieties. 

The seed is globular, 1.5-2.5 mm. in diameter, and is of a dark brown, 

almost black color. On the surface it is dull but never reticulated, even 

under a lens, a striking distinction from brown and black mustard. 

Fig. 148. Rape (Brassica Napus). Seed 
in cross section. S spermoderm con- 
sists of ep epidermis, sub subepidermal 
layer, pal palisade cells, and pig pig- 
ment cells; E endosperm; C cotyledon 
with aep outer epidermis. X160. (K. 
B. Winton.) 

Fig. 148a. I. Common Rape. Elements of seed in surface view. Significance of ref- 
erence letters as in Fig. 148. II. Palisade cells of German rape (B. Rapa). X160. 
(K. B. Winton.) 


Rape corresponds in general structure to black mustard, but the 
Epidermis and the Subepidermal Layer of the ripe seed form an indis- 
tinct coat with little or no evidence of cellular structure in cross section 
and easily overlooked in surface view (Figs. 148 and 148a, I, ep and sub). 

The Palisade Cells are of nearly uniform height, hence the absence 
of reticulations such as occur on the seeds of black and brown mustard. 

RAPES. 187 

Another striking distinction from the mustards lies in the larger size 
of the palisade cells, which, as seen in surface view, have an average 
diameter of 20 ft and often reach 30 /i. 

Harz states that the diameter of the lumen of each cell is about as 
great as the breadth of the double walls, whereas in German rape (Fig. 
148a, II) the lumen is narrower. Hanausek and Gram confirm this 
distinction, but Collin and Perrot state that the lumen n """-erman rape 
is the larger. Pieters and Charles place chief dependence on the more 
regular height of the palisade cells, which varies not more than 3 pt, while 
in German rape it varies from 5-7 fi. 

The faintly reticulated appearance of the spermoderm of German 
rape which Collin and Perrot regard as the chief means of distinction, 
is explained by the variation in the height of the palisade cells. 

The remaining coats of the spermoderm, also the endosperm and 
embryo, agree in structure with the corresponding coats of black mustard, 
though myrosin cells are less numerous in the embryo. 


The characters of chief use in diagnosis are the large size of the pali- 
sade cells (average diameter 20 //), their uniform height, and the 
consequent absence of reticulations. Epidermal cells are seldom distin- 
guishable. Among the foreign seeds of rape cake are false flax (Came- 
lina sativa), treacle mustard [Erysimum orientate), wild radish (Raphanus 
Raphanistrum) , charlock (Brassica arvensis), hedge mustard {Sisym- 
brium officinale and S. Sophia), penny-cress (Thlaspi arvense), shepherd's 
purse {Capsella Bursa-Pastoris) , peppergrass {Lepidium campestre), and 
other cruciferous seeds. 


See General Bibliography, pp. 671-674; Beneke (2); Bohmer (6, 10, 23); Collin 
et Perrot (9); Hanausek, T. F. (17, 48); Harz (18); Hassall (19); Moeller (29). 

Also see Bibliography of Cruciferae, p. 176: Burchard; Claer, et Thyes; Gram; 
Hartwich u. Vuillemin; Kobus; Pieters and Charles; Schroder; Sempolowski. 


The seeds of Brassica Rapa L., known in Germany as Rtibsen, are 
smaller than those of common rape and show faint reticulations. 

The differences in microscopic structure of the two species are noted 
under common rape. 

r 88 OIL SEEDS. 


Sarson, or Indian colza (Brassica campestris L. var. Sarson Prain, 
Sinapis glauca Roxb.), has both white and brown seeded varieties, 
although the latter are rare. The seeds have been introduced into Europe 
as adulterants of white mustard, which they closely resemble. Kinzel 
believes that the "Guzerat Raps" of Wittmark belongs under this variety, 
and it is probable that the same is true of the yellow Indian rape described 
by Steffeck and the false white mustard to which Harz gave the name 
B. Iberijolia. The seed is without reticulations, and in general appear- 
ance closely resembles white mustard. 

Unlike white mustard seed, the epidermis and the subepidermal layer 
form a nearly homogeneous layer with indistinct division into cells. In 
some, if not all varieties, the palisade cells are broader than in white 
mustard, being about the same size as in common rape. 

The cake from this and the three following oil seeds is imported into 
Europe from India. 

According to Kinzel, the chief impurity is the black triangular seeds 
of Asphodelus lenuijolius, which resemble the fruits of black bindweed 
\Polygonum Convolvulus), except that they are transversely wrinkled. 
The epidermis obtained by scraping the opaque spermoderm is char- 
acterized by the thin lamellae, which appear like 4-6 concentric circles. 

See Bibliography of Cruciferae, p. 176: Kinzel. 


According to Prain, tori or brown Indian rape is Brassica Napus 
L. var. dichotoma Prain. 

It is grown both as an oil seed and as a vegetable. 

Kinzel states that the epidermis in cross section does not appear 
cellular, and that the aleurone cells are often in two layers. He further 
notes that the highest palisade cells form usually distinct but very narrow 
reticulations, and that the lumens of the palisade cells arc as broad as 
those of European rape. 

See Bibliography of Cruciferae, p. 176: Kinzel. 



The Indian plant asi-rai, according to Prain and Kinzel, is Brassica 
juncea Hook. f. et Thorns. It yields a brown seed much like that of 
black mustard, although somewhat larger. The meshes on the surface 
are distinctly seen with the aid of a lens. 

Unlike brown mustard, the epidermis shows scarcely any evidence 
of cellular structure. 


See Bibliography of Cruciferae, p. 176: Kinzel. 


The seeds of the plant known in India as palai, palangi or pahari rai, 
etc., {Brassica rugosa Prain), are brown and finely reticulated. 

According to Kinzel, this species is distinguished from all other 
Indian rapes by the ce^ular structure of the epidermis. Treated with 
sulphuric acid and alkali, the palisade cells are of a more yellow-brown 
color than in other varieties. 


See Bibliography of Cruciferae, p. 176: Kinzel. 


Kinzel states that the seeds of Sinapis dissecta Lagasca (Brassica 
dissecta Boiss.) frequently occur in Russian linseed and rape seed, as 
well as in the cake made from these seeds. 

Burchard finds that the histological structure is very similar to that 
of white mustard, the chief differences being that the palisade and pig- 
ment layers contain a brown pigment, and the palisade layer displays 
narrow reticulations, due to the unequal height of the cells. 

See Bibliog., p. 176: Bohmer; Burchard; Gram; Hart wich u. Vuillemin; Kinzel. 




This plant (Eruca sativa Lam.) is a common weed in Southern Europe 
and India. The seeds are usually yellow, but occasionally are red- 
yellow or mottled with green-brown spots. The spermoderm is smooth. 
Gram notes the following points with regard to the histological structure : 
The epidermal cells contain mucilaginous substance in layers with axial 
columns. The double contour of the walls as seen in surface view is 
due to a thickening of the outer walls at the edges of the cells. No sub- 
epidermal layer is evident. The palisade layer has thickened radial 
walls only in its inner half, where the double walls are about the thick- 
ness of the lumen. 


See Bibliog., p. 176: Bohmer; Collin et Perrot; Gram; Hartwich u. Vuille- 


In Germany, Holland, and some other countries, false flax (Camelina 
sativa L.) is sparingly grown for its seed, which yields oil and cake. It 
also occurs as a weed in flax fields and the seed as an impurity of lin- 
seed and rape seed. 


Fig. 149. False Flax (Camelina sativa). Fig. 150. False Flax. Seed in cross section. 
Seeds, natural size and enlarged. 5 spermoderm consists of cp epidermis with 

(Nobbe.) muc escaping mucilage, pal palisade cells, 

and p parenchyma; E endosperm; C cot- 
yledon with aep outer epidermis and al 
aleurone cells. X160. (K. B. Winton.) 

The brown seed (Fig. 149) is 1.5 mm. long and about half as broad, 
its surface being finely granulated, but not reticulated. A pronounced 
longitudinal ridge marks the position of the radicle. 




The Spermoderm (Fig. 150, S; Fig. 150a) consists of epidermis, 
palisade cells, and an inner layer corresponding to the pigment layer 
of the mustards and rapes. 

There is no evidence of a sub- /*■'£}'- ''Tf^lT^IL ^'^"V"^-® 

epidermal layer in the ripe 


1. The EpidermalCells (ep) 
average about 50 fi broad, but 
often reach 100 fi. They are 
characterized by the presence 
in each cell of an axial column 
of mucilaginous substance 
which, on the addition of 
water, bursts through the 
outer wall in the form of a long tapering cylinder. 

2. The Palisade Cells (pal) are brownish and striated. Their average 
breadth is 45 /*, their maximum 90 /*. The double radial walls are 
15-20 fi thick, but only about 15 fi high. 

3. The Inner Layers of the spermoderm, corresponding to the pig- 
ment cells of allied seeds, consist of compressed cells, which are clearly 
evident in cross section only after treatment with chloral hydrate. 

The Endosperm and Embryo are practically the same as in the mus- 
tards, except that the aleurone grains of the embryo seldom exceed 5 fi. 

Fig. 1500. False Flax. Elements of seed in sur- 
face view. Significance of reference letters as 
in Fig. 150. X160. (K. B. Winton.) 


Seeds and cake of false flax are identified by the long tapering 
mucilage column which bursts through the outer epidermis on the addi- 
tion of water, also by the broad, low palisade cells (Fig. 150a). 


See General Bibliography, pp. 671-674: Benecke (2); Bohmer (6, 10, 23); Collin 
et Perrot (9); Hanausek, T. F. (17, 48); Harz (18). 

Also see Bibliography of Cruciferae, p. 176: Gram; Kobus; Sempolowski. 
Nevtnny: Die Samen von Camelina saliva. Ztschr. Nahr.-Unters. u. Hyg. 1887, 1, 85. 
Van Pesch: Leindotter-Kuchen. Landw. Vers.-Stat. 1892, 41, 94. 



Sisymbrium officinale Scop., 5. Sophia L., and other species of this 
genus, known as hedge mustard and by other names, are common weeds 
in both Europe and America. 

The brown seeds are minute and more or less irregular in shape. 

Gram notes that the epidermis in S. officinale contains a mucilaginous 
substance in layers, with an axial column in each cell which does not 
readily escape on addition of water, also that the palisade cells are thick- 
ened only at the very inner ends. 

According to the same author the seeds of S. Sophia are very similar 
to those of shepherd's purse, but the palisade cells are not so broad. 

See Bibliography of Cruciferse, p. 176: Eohmer; Gram. 


Shepherd's purse (Capsella Bursa-Pastoris Moench) has a seed of 
much the same shape and color as false flax, but of about half the size. 
The structure (Figs. 151 and 151a) is also similar, but the epidermal 


Fig. 151. Shepherd's Purse (Cap- 
sella Bursa-Pastoris). Seed in 
cross section. 5 spermoderm 
consists of ep epidermis, pal pal- 
isade cells, and p parenchyma; 
E endosperm; C cotyledon with 
aep outer epidermis and al aleu- 
rone cells. X160. (K. B. 


Fig. 151a. Shepherd's Purse. Elements of 
seed in surface view. Significance of ref- 
erence letters as in Fig. 1 5 1 . X160. ;K. 
B. Winton.) 

cells are in rows, the mucilage columns escape less readily, and the pal- 
isade cells are not so broad, the average diameter being 30 p., the max- 
imum 60 fi. 


See General Bibliograpny, pp. 671-674; Bohmer (6, 10, 23); also see Bibliogra- 
phy of Cruciferae, p. 176: Gram. 




Several species of Lepidium, notably L. Virginicum L., L. campestre 
Br., and L. sativum L., are common weeds. The seeds of the first named 
species occur in American grain and flax seed. They are small (1-1.3 
mm.), yellow brown, minutely margined, and have accumbent cotyledons. 
They are also more or less flattened. 

The palisade cells of L. campestre are unusually high. 

The striking microscopic characters (Figs. 152 and 152a) are the 
central columns of the epidermal cells, irregularly broadened at the 

Fig. 152. Pcppergrass {Lepidium 
Virginicum). Seed in cross sec- 
tion. 5 spermoderm consists of 
ep epidermis, pal palisade cells, 
and p parenchyma; E endo- 
sperm; C cotyledon with aep 
outer epidermis and al aleurone 
cells. X160. (K. B. Winton.) 

Fig. 1520. Peppergrass. Elements of seed in 
surface view. Significance of reference 
letters same as in Fig. 152. X160. (K. B. 

outer ends, and the palisade cells (up to 40 fi) of the usual type. The 
epidermal cells of the immature seed contain numerous starch grains 
which are replaced at maturity by mucilage. 

See Bibliography of Cruciferae, p. 176: Bohmer; Gram. 


According to Bohmer and Gram, the seeds of this common weed 
(Thlaspi arvense L.) frequently occur in linseed 
and rape cake (Fig. 153). 

The epidermis and parenchymatous second 
layer form a membrane of obliterated cells over 
the palisade layer. In cross section the palisade 
cells are of unequal height and have strongly 
Fig. 153. Field Penny- thickened inner and side walls. Their appearance 

cress (Thlaspi arvense). . r . ..... . . 

a and b seed enlarged; m surface view is highly characteristic, owing to 

c seed natural size. 

the arrangement of the high cells in longitudinal 


rows forming parallel ribs of a darker color than the intervening chan- 

See Bibliography of Cruciferas, p. 176: Eohmer; Gram. 


Seeds of this weed (Erysimum orientale R. Br.) occur in rape seed 
from both Europe and India. They are dull brown, and have a nearly 
smooth spermoderm. 

Gram's figures show the following details: 

The epidermal cells contain mucilage which escapes from each as 
a long conical body. The thickened radial walls are punctured with 
radially elongated pores, and as a consequence appear toothed in surface 
view, and scalariform in section. The palisade cells have broad lumens 
and are seldom thickened except at the inner ends. 

See Bibliography of Cruciferae, p. 176: Bohmer; Gram. 


Gram finds seeds of the wild radish (Raphanus Raphanistrum L.) 
in small amounts in European rape cake. The seeds are globular, 
much larger than those of rape, from which they are further distinguished 
by their red-yellow color. The epidermal and subepidermal cells are 
broad, and the latter have collenchymatously thickened angles. The 
palisade cells are rather low, and of unequal height. In surface view 
they display moderately distinct reticulations. The lumen is usually 
thicker than the walls. 

See Bibliography of Cruciferae, p. 176: Gram. 


The brown-gray, smooth seeds of Barbarea vulgaris R. Br., are occa- 
sionally present in rape seed. 

The mucilage is situated in the outer portion of each epidermal cell, 
extending inward at the sides. The radial walls are often thickened. 
In some seeds the subepidermal coat is not evident, in others it consists 
of one, or seldom two, layers. 


Characteristic of the palisade cells are their large size, large lumen, 
and the single crystal, less often the costal cluster, present in each. 

See Bibliography of Cruciferse, p. 176. Gram. 


The fruits (achenes) of the sunflower, the tarweed (madia), and the 
niger plant are of local importance. They are characterized by the 
leathery pericarp, with strongly developed bast-fiber bundles, also by 
the black pigment plates which cover these bundles. The species are 
easily distinguished by certain layers of the pericarp and spermoderm 
described under each. 


Although a native of tropical America, the sunflower (Helianthus 
annuus L.) is grown for its oleaginous seed chiefly in Europe and Asia. 
In Russia, Hungary, Italy, and India, sunflower oil is used both as a 
human food and in the arts, and the cake is fed to farm animals. The 
sunflower is cultivated in other countries chiefly for bird seed or as an 
ornamental plant. 

The obovoid achenes are more or less four-sided and flattened. Al- 
though variable in size, they are seldom less than 10 mm. long. In 
some varieties the pericarp is nearly black, in others, striped with black 
and white. 


The Pericarp (Fig. 154). is dry and brittle, and may be readily 
separated from the seed. 

1. The Epicarp Cells (Fig. 154, ep') are large, usually elongated, 
with rather thick, porous walls. Stomata are absent. Dark-colored 
contents are present throughout in black seeds, but only in some of the 
cells of striped seeds. Characteristic of this fruit are the broad, thin- 
walled hairs (h, h', c), usually in pairs, most of which are broken off in 
cleaning the seed. As a rule, the members of each pair are united for 
nearly their entire length. T. F. Hanausek has found that these hairs 
are attached at their bases to a specially differentiated cell of the epi- 
dermis, known as a "foot cell" (/), one hair being seated directly on 
this foot cell, the other attached to its side. 



2. Hypoderm (sep). Three or more layers of cells characterized 
by their numerous minute pores form this coat. In cross section the 
cells, like cork cells, are quadrilateral and arranged in radial rows. 

3. Pigment Plates (hb). As is true of madia and niger fruits, the 
pericarp of varieties of sunflower with dark or striped seeds, has a de- 
posit of pitch-like substance between the hypoderm and the fiber bundles. 
This material was at one time regarded as an intercellular deposit, but 
has been shown by T. F. Hanausek to consist of a layer of cells (III, hb), 

Fig. 154. Sunflower (Hettanthus annuus). I Cross section of outer layers of pericarp: 
ep epicarp with c cuticle; sep hypoderm; hb pigment plates, b fiber bundles separated 
by m parenchyma; II hairs: a attached to foot cell, b without foot cell, c seen from 
side. Ill cross section of immature fruit showing hb cells which later form pigment 
plates and b undeveloped fibers. (T. F. Hanausek.) 

disorganized through what appears to be a humincation process. In 
the early stages of growth the loosely arranged elongated cells bear numer- 
ous minute protuberances on the outer and radial walls, which undergo 
the process of disorganization before the cell proper. This observation 
led him to surmise that the change was due to oxidation, the air spaces 
formed by the protuberances facilitating the absorption of oxygen. 

4. The Fiber Bundles (b) consist of several layers of longitudinally 
arranged fibers. Proceeding from without inward, the cells increase 
in size; the porous walls diminish in thickness. Not only are these 


bundles larger than in madia and niger, but the elements are broader 
and have much broader lumens (often 50 /i) . The bundles are separated 
by radial rows of thin-walled cells (m) reminding one of medullary rays, 
and each adjoins on its inner side a small vascular bundle. 

5. Parenchyma. An exceedingly thin-walled, loose parenchyma com- 
pletes the pericarp. In the ripe seed the cells are much compressed, 
forming a white, papery tissue. 

Spermoderm. A delicate membrane, consisting of spermoderm and 
endosperm, closely envelops the seed. 

1. The Outer Epidermal Layer as seen in surface view consists of 
rounded cells (about 50/*), with rather thick, obscurely beaded walls. 

2. Spongy Parenchyma, through which ramify the bundles of the 
raphe and its branches, forms the middle layer. 

3. An Inner Epidermis of more or less rectangular cells 8-20 n in 
diameter, may be seen in section on heating with chloral, and in surface 
view without treatment with reagents. 

Endosperm. One, sometimes two, layers of typical aleurone cells 
15-50 /j. in diameter are readily found, both in cross sections and in sur- 
face mounts. Rectangular cells predominate, although triangular and 
polygonal forms also occur. 

The Embryo consists of two folded cotyledons and a short radicle. 
The folded cotyledons have several rows of palisade cells adjoining the 
inner epidermis — the upper epidermis after unfolding. These contain 
irregularly spherical aleurone grains 3-12 (i in diameter, and fat globules. 
Only small aleurone grains occur in the epidermal cells. 


As sunflower achenes are shelled before expressing the oil, the cake 
contains only such fragments of the pericarp as escape separation. These 
are readily identified by the twin-hairs (Fig. 154, II), the cork-like hypo- 
derm with numerous fine pores, and the large fibers. 

The spermoderm, endosperm, and embryo do not possess any char- 
acteristic tissues. 


See General Bibliography, pp. 671-674: Benecke (2); Bohmer (6, 10, 23); Collin (8); 
Hanausek, T. F. (17, 48); Harz (18); Moeller (29). 
Hanatjsek, T. F. : Zur Entwicklungsgeschichte des Perikarps von Helianthus annuus. 

Ber. deutsch. Bot. Ges. 1902, 20, 449. 
Heineck: Beitrag zur Kenntniss des feineren Baues der Fruchtschalen der Composite^. 

Inaug.-Diss. Giessen. 1890. 



KoBtrs: Kraftfutter und seine Verfalschung. Landw. Jahrb. 1884, 13, 813. 
Kraus: Ueberden Bau der trockenen Perikarpien. Inaug.-Diss. Leipzig, 1866, 66. 
Ppistee: Oelliefernde Kompositenfriichte. Landw. Vers.-Stat. 1894, 43, 441. 


Common tarweed, known in Chili as "Madi" {Madia sativa Mol.), 
is one of severa 1 species of this genus natives of the Pacific coast of North 
and South America. It is cultivated as an oil seed in parts of the Ameri- 
can continent and more extensively in Germany. 

The slender, ribbed achenes, 4-8 mm. long, 2 mm. wide at the apex 
tapering to the base, are borne in heads 3-6 cm. in diameter. The 
achenes are usually light in color, but sometimes are nearly black. 


Pericarp (Fig. 155, F; Fig. 156). 1. Epicarp (ep). The cells 
are longitudinally elongated, variable in size, with colorless, distinctly 
beaded walls and a thickened cuticle. 

Fig. 155. Madia (Madia saliva). Cross section of fruit. F pericarp consists of ep 
epicarp, hy hypoderm, br pigment plates, / fiber bundles, m partitions, and p paren- 
chyma; 5 spermoderm, with R raphe; E endosperm; C cotyledon containing al aleurone 
grains. X 160. (Winton.) 

2. Hypoderm (hy). Thin-walled more or less collapsed cells form 
the second layer. 

3. Pigment Plates (br). As in niger seed and some varieties of sun- 
flower, the fiber bundles are covered with dark-colored plates of a ma- 
terial insoluble in all the common reagents, including boiling alkali. In 
surface view the markings, resembling those of a tortoise shell, which are 
due to the variable thickness of the pigment material, and the rows of 



minute pores appearing as light spots in the dark field, make this layer 
the most striking in the fruit. 

4. Fiber Bundles (/). The fibers are 5-15 (i in diameter and often 
are 1 mm. long, being smallest in the outer layers. Between the bundles 
are groups of thin-walled, more or less longitudinally elongated cells, 
forming wedge-shaped partitions (m). 

5. Parenchyma (p). Several rows of partially collapsed parenchyma 
cells form the inner layers of the pericarp. 

The Spermoderm (Figs. 155 and 156, S) consists of one distinct layer 
of parenchyma cells without any striking characters, and other less dis- 
tinct layers near the raphe bundles. 

Curiously shaped, pitted cells (Fig. 156, sc), some nearly isodiametric, 
others greatly elongated, are present at the base of the seed, the longer 

Fig. 156. Madia. Elements of fruit in surface view, ep epicarp; hy hypoderm; br 
pigment plates; / fiber bundle; 5 spermoderm with R raphe bundle; sc pitted cells 
at base of spermoderm; End endosperm. X160. (Winton.) 

forms extending in bundles toward the apex. These bundles appear 
to be distinct from the raphe and its ramifications. 

The Endosperm (Figs. 155 and 156, E) is, represented by a single 
layer of thick-walled, often quadrilateral, aleurone-cells. 

Embryo. Beneath the outer epidermis of the folded cotyledons 
(Fig. 155, C) are several layers of isodiametric cells, but adjoining the inner 
epidermis are three to four layers of typical palisade cells. Aleurone 
grains (2-6 p) and fat are the only visible contents. 



Madia fruit has much the same structure as sunflower and niger 
fruits; but is distinguished from the former by having no hairs on the 
epicarp (Fig. 156, ep), a single layer of hypodermal cells, and fibers 
(/) with relatively small diameters; while it differs from niger seeds in 
having the walls of the epicarp beaded, an inconspicuous hypoderm layer 
(no rail-shape cells), and the walls of the spermoderm (S) straight and 


See General Bibliography, pp. 671-674: Benecke (2); Bohmer (6, 10, 23) ; Collin (8); 
Hanausek, T. F. (17, 48); Harz (18). 

Pfister: Oelliefernde Kompositenfriichte. Landw. Vers.-Stat. 1894, 43, 441. 
Winton: The Anatomy of Certain Oil Seeds with Especial Reference to the Microscopic 
Examination of Cattle Foods. Conn. Agr. Exp. Sta. Rep. 1903, 175. 


The fruit of Guizolia Abyssinica (L) Cass. (G. oleijera D.C.), a 
composite plant, is an important oil seed in Abyssinia, its native country, 
and alsoin India. It has been introduced into Europe and America, but 
has not been extensively cultivated as yet. 

The black achenes are shaped like those of madia, but are much 
smaller, seldom over 5 mm. long and 1 mm. broad at the apex. 


Pericarp (Fig. 157, F; Fig. 158). 1. The Epicarp cells (ep) are dis- 
tinguished from those of madia by their greater length and the absence 
of pores. 

2. Hypoderm (hy). Pfister has shown that the isolated, longitudi- 
nally elongated cells of this layer are shaped like railway rails, resembling 

Fig. 157. Niger Seed {Guizotia Abyssinica). Cross section of hull. F pericarp consists 
of ep epicarp, hy hypoderm, br pigment plates, / fiber bundles, m partitions and p paren- 
chyma; 5 spermoderm; E endosperm. X300. (Winton.) 

in cross section the hour-glass cells of the legumes. The color of the 
seed is largely due to the black pigment in this layer. 



3. The Pigment Plates (br) are similar to those of madia seed, but 
the cross markings are nearer together and not so distinct. 

4. The Fiber Bundles (/) are smaller than the similar bundles of 
madia, and the individual fibers are narrower. 

5. Parenchyma. The partitions between the fiber bundles (m), and 
also the inner layers of the pericarp (p), consist of parenchyma cells which, 
in the layers adjoining the spermoderm, are usually compressed. 

Spermoderm. 1. Reticulated Cells (Figs 157 and 158, S). Charac- 
teristic of this seed are the reticulated cells with wavy side walls, forming 
the outer layer of the spermoderm. 

2. Inner Layers. One or more layers of obliterated cells form the 
inner spermoderm. 

Endosperm (Fig. 157 and 158, E). As in madia, the endosperm 

Fig. 158. Niger Seed. Pericarp, spermoderm and endosperm in surface view, ep epi- 
carp; hy hypoderm; br pigment plates; / fiber bundle; S spermoderm; E endosperm. 
X 300. (Winton.) 

consists of a single layer of thick-walled aleurone cells, often of retangular 

Embryo. The thin-walled cells of the embryo contain aleurone 
grains and fat, and are not distinguishable from those of madia. 


Niger cake is utilized as a cattle food. The characteristic elements 
are the rail-shaped cells of the hypoderm (Fig. 158, hy) with their dark 


contents, and the outer layer of the spermoderm (5). These are 
rendered distinct by treatment with alkali. 

See Bibliography of Madia, p. 200. 


A number of oil seeds and fruits belonging to widely separated fam- 
ilies are of even greater importance for oil production than cruciferous 
seeds. Of those here described, linseed, cottonseed, castor bean, sesame 
seed and poppy seed are true seeds, while hemp seed is a dry fruit, and 
the olive is a fleshy fruit. 


The flax plant (Linum usitatissimum L. order Linacece) is valuable 
not only for its fibers, but for its seed, which yields one of the most use- 
ful of the vegetable oils, also a concentrated cattle food. Since the fiber 
is in its best condition before the seeds reach maturity, it is not practicable 
to secure a yield of both fiber and seed from the same crop. 

Flax is grown for seed throughout the temperate zone, particularly in 
India, Russia, Egypt, and the United States. 

The yellowish pods (Fig. 159), 8 mm. in length, are slightly broader 
than long, with live, pointed sepals and a slender pedicel. Each of the 
five locules is incompletely halved by a false dis- 
sepiment, making a 10-celled fruit which dehisces 
at maturity into ten valves. Each cell contains a 
single flattened, anatropous seed (4-6 mm. long) 
with a slightly beaked base. To the naked eye 
^mm^usitatulimiT De- the surface is smooth and lustrous, but under a 
Wscing fruit wiA sepals l ens appears slightly roughened. The Indian seed 
is yellow, the ordinary varieties brown. The 
straight embryo consists of two long, thick cotyledons and a short radicle, 
the cotyledons being several times as thick as the inclosing endosperm 
(Fig. 21). 




The Calyx consists of an outer and an inner Epidermis of elongated, 
wavy -walled cells with simple stomata and a mesophyl of parenchyma cells. 

Pedicel. Four tissues are present: (1) Epidermis of elongated rect- 
angular cells; (2) Subepidermis of several parenchyma layers; (3) Bast 


Fig. 160. Flax Fruit.^ Pericarp in cross section, epi epicarp; cr crystal cells; hy l pro- 
jections of hypoderm; hy 2 hypoderm; mes mesocarp; end endocarp. X160. (K. 
B. Winton.) 

Fibers with cross-striated joints like those of the linen fibers of com- 
merce ; (4) Xylem of spiral and pitted vessels, wood fibers, and paren- 

Fig. 161. Flax Fruit. Elements of pericarp in surface view, epi, epicarp; cr crystal 
cells; hy l projections of hypoderm; hy 2 . hypoderm; mes mesocarp; end endocarp. 
X160. (K. B. Winton.) 

Pericarp (Figs. 160 and 161). The Epicarp {epi) consists of partially 
collapsed cells. In surface view they are elongated and often show 
yellowish contents. 

2. Crystal Cells {cr). These are arranged in indistinct rows forming 
an interrupted layer. They are rounded and have light-brown walls 



which are so thickened that the single monoclinic crystal of calcium 
oxalate completely fills the cavity. 

3. Hypoderm. The pitted cells are characterized by the numerous 
projections of the outer walls (hy 1 ) and the pitted side walls (hy 2 ). 

4. The Mesocarp consists of one to several layers of pitted cells (mes). 

5. Endocarp. The cells of this layer, as well as of the papery dis- 
sepiment (Fig. 162), into which it passes, are transparent, pitted, usually 

elongated; and are arranged 
in beautiful parquetry patterns. 
These and the crystal cells are 
highly characteristic. 

Spennoderm (Fig. 163, S; 
Fig. 164). Sections of the dry 
seed may be cut after embedding 
in parafhne. 1. Epidermis. If 
water is gradually added to a 
cross section mounted in alcohol r 
the outer wall is seen to have a 
stratified appearance due to a 
mucilaginous substance which 
nearly fills the cavity (Fig. 163, 
ep) . It is this mucilaginous sub- 
stance that gives the seed its 
value in medicine. In surface 
view (Fig. 164, ep 1 ), the cells are 
polygonal, with a finely granular cuticle. The layer is brittle and readily 
breaks up into pieces through straight or irregular cracks. 

2. Round Cells (Fig. 163, p; Fig. 164, r). One or two layers of 
yellow cells with circular cavities and marked intercellular spaces form 
the second layer. Their appearance in surface view is characteristic. 

3. Fiber Layer (/). Strongly thickened, porous fibers longitudinally 
arranged make up this layer. They vary up to 250 p in length and 10 // 
in breadth. As may be seen in cross section, their radial diameters 
are much greater than their breadth. 

4. Cross Cells (tr). Several layers of exceedingly thin-walled, more 
or less obliterated, colorless cells cross the fibers of the preceding layer 
at right angles. 

Layers 1 to 4 inclusive usually separate from the seed together, pre- 
senting in surface view a highly characteristic appearance. 

Fro. 162. Flax Fruit. Dissepiment in surface 
view. X160. (K. B. Winton.) 



5. Pigment Layer (Fig. 163, g; Fig. 164, pig). Equally characteris- 
tic are the square or polygonal cells of this layer, with finely porous walls 
and deep yellow or brown contents. This material is insoluble in alcohol 
or ether and is colored dark blue by ferric chloride. It often separates 
from the cells in the form of rectangular plates. 

Fig. 163. Linseed. Cross section of S spermoderm and E endosperm, ep outer epidermis; 
p round cells; /fiber layer; tr cross cells; g pigment cells. (Moeller.) 

The Endosperm (E) is usually from 2 to 6 cell layers thick, being thinnest 
at the edges. The cells have thicker walls than those of the embryo 
and contain fat and distorted aleurone grains, each grain with a globoid 
in a sort of beak and an indistinct crystalloid in the body. 

Embryo (Fig. 164, ep 2 and mes) . The cells contain large, ovoid aleurone 
grains up to 20 ji long, like those of the endosperm, also minute grains. 

Tschirch and Oesterle recommend mounting in alcohol and running 
a water solution of iodine under the cover, thus staining the crystalloid 


Flax Bran consists largely of pericarp tissues. The papery endocarp 
and dissepiment (Fig. 162) are characteristic. 

Ground Linseed is used chiefly as a drug, but linseed cake from the 
oil presses and the ground cake, known as linseed meal, are highly es- 
teemed by cattle feeders. 



The conspicuous elements are pieces of the yellow outer spermoderm, 
consisting of round cells (Fig. 164, r), fibers (/), and cross cells (ir), 
and also the nearly square, faintly beaded pigment cells (pig) with brown 
contents. These tissues are highly characteristic and permit the detec- 


Fig. 164. Linseed. Elements in surface view, ep 1 epidermis of spermoderm; r round 
cells; / fiber layer; x middle lamellae of fiber layer; ir cross cells; pig pigment cells; 
E endosperm with al aleurone grains; ep 2 epidermis of cotyledon with sto immature 
stoma; mes mesophyl. X300. (K. B. Winton.) 

tion of small amounts of linseed products in mixtures. Starch should 
not be present in appreciable amount. 

Linseed Cake and the ground cake known as Linseed Meal are often 
contaminated with cruciferous and other seeds. 

The meal is itself used as an adulterant for black pepper and other 
spices, and as an ingredient of many mixed cattle foods. 


See General Bibliography, pp. 671-674: Benecke (2) ; Berg (3) ; Bohmer (6, 10, 23); 
Collin (8); Fluckiger (11); Hanausek, T. F. (10, 16, 17, 48); Harz, (18); Mac6 (26); 
Meyer, A. (28); Moeller (29 30, 31, 32); Schimper (37); Tschirchu. Oesterle (40); 
Villiers et Collin (42); Vogl (43, 45). 



Berghe: Tourteaux et Farines de Lin. Bruxelles, 1891. 

Cramer: Ueber das Vorkommen und die Entstehung einiger Pflanzenschleime. Pflan- 

zenphysiologische Untersuchungen von C. Nagali u. C. Cramer, Zurich, 1855. 
Goderin: Etude histologique sur les tegument seminaux des Angiospermes. Soc. 

d. Sci. d. Nancy, 1880, 109. 
Haselhoff u. van Pesch. Ueber Leinsamenkuchen und Mehl. Landw. Vers.-Stat. 

1892, 41, SS 
Kobtts: Kraftfutter und seiner Verfalschung. Landw. Jahrb. 1884, 13, 813. 
Koran: Der Austritt des Schleimes aus dem Leinsamen. Pharm. Post, 1899, 32. 
Sempolowski : Ueber den Bau der Schale landwirthschaftlich wichtiger Samen. Landw. 

Jahrb. 1874, 3, 823. 
Winton, K. B.: Histology of Flax Fruit. Bot. Gaz., 1914, 58, 445. 


The varieties of upland or short-staple cotton commonly cultivated 
for fiber are classed under Gossypium herbaceum L. (order Malvacece), 


Fig. 16?. Cotton Seed {Gossypium herbaceum). I transverse section. II longitudinal 
section. S spermoderm; NE perisperm and endosperm; C cotyledons; R radicle. 
X4. (Winton.) 

although quite probably some of these varieties have been obtained by 
crossing with other species. Other species of economic importance are Sea 
Island or long-staple cotton (G. barbadense L.), and tree cotton (G. ar- 
bor eum L.). 

The culture of cotton has extended from India, its native country, 
to northern Africa, the southern states of the United States, Brazil, and 
other warm regions. 

Within the bolls are borne numerous seeds in a mass of fibers, the 


latter being but epidermal cells of the spermoderm prolonged as hairs 
(Fig. 165). After ginning, the seeds of upland cotton are still enveloped 
by a close ground fiber, often gray or green in color, which cannot be 
easily removed. Sea Island cotton seed is nearly free from ground fiber. 
Freed from the fiber, the pointed, egg-shaped, black or dark-brown seed 
is 6-12 mm. long. The chalaza is a little to one side of the broad upper 
end, the hilum and micropyle at the pointed lower end, the raphe con- 
necting them being evident as a ridge on the surface. A shell-like spermo- 
derm and a thin skin consisting of perisperm and endosperm inclose the 
bulky embryo, the latter having cotyledons which in cross section are 
dotted with minute dark-brown resin cavities. 


The Spermoderm (Fig. 166, 5; Fig. 167) is 300 ji thick, separating 
readily from the seed. The inner surface is brown with a whitish opales- 

1. Epidermis (ep). Over the raphe the epidermis is 30-40 fi thick, 
but in other parts it seldom exceeds 25 /1. The cells are conspicuous 
because of the thick (5-12 ,u), stratified, yellow walls and the dark-brown 
contents. In surface view, the cells are irregular in shape and van- in 
size from less than 10 to over 60 ft. About the hairs they form rosettes. 
The hairs of cotton are twisted, thus distinguishing them from all other 
textile fibers. Stomata with thin, colorless-walled guard cells occur 
either singly or in pairs. 

2. Outer Brown Coat (br). The hypodermal coat consists of thin- 
walled, often compressed cells, with indistinct contour and brown contents. 
Over most of the surface, this coat is but 20-40 /n thick, and consists of 
only two or three cell layers, but about the raphe it is several times 

3. Colorless Cells (w). The next layer consists of small (10-30 ,u), 
colorless cells, with sharply defined walls 2-3 u thick. Cells divided by 
tangential partitions occur not infrequently. Hanausek states that these 
cells contain occasional oxalate crystals or granular masses; most of 
them, however, are empty. 

4. Palisade Cells (pal). Over one-half of the thickness of the 
spermoderm is due to the thickened palisade cells. These remark- 
able and exceedingly characteristic cells are 8-20 p. wide, and about 
150 fi long, each consisting of an outer portion of about one-third the 
length of the cell with nearly colorless walls, and an inner portion 



with yellowish- brown walls. The lumen in the outer portion of each 
cell is narrow except for a globular enlargement at the inner end, 4-6 // 
in diameter, containing a dark-colored material. Seen in tangential sec- 
tion, this cavity has radiating branches. An indistinct light line adjoins 


Fig. 166. Cotton Seed. Cross section. 5 spermoderm consists of ep epidermis with 

' h hair br outer brown coat with R raphe, w colorless cells, pal palisade cells, and 

a b and c la vers of inner brown coat; N perisperm; E endosperm; C cotyledon with 

aep outer epidermis and iep inner epidermis; s resin cavity surrounded by 2 mucilage 

cells- al aleurone grains; k crystal cells; g procambium bundles. X160. (Winton.) 

the outer wall. No lumen at all appears in the inner portion of these 
cells in cross section, but in tangential section faint radiating lines are 
evident, due, according to von Bretfeld, to lamella arranged about the 
axis of the cell. Individual cells isolated by macerating with Schulze's 
solution and treated with chromic acid show clearly this differentiation. 


The same author found that the outer portion has all the chemical and 
optical properties of pure cellulose, the inner portion, those of lignified 
cellulose. Cross sections viewed with polarized light exhibit with a dark 
field a beautiful play of color in the outer, a clear white light in the inner 

5. The Inner Brown Coat. In the outer layer of this coat (a), the 1 
cells are polygonal, and well denned both in cross section and surface 
view. Proceeding inward, the tissue takes on the characters of a typical 
spongy parenchyma, the cells in th« innermost layers being much com- 

FlG. 167. Cotton Seed. Surface view of outer layers, ep epidermis of spermoderm 
with h l hair and sto 1 stoma; br outer brown cells; w colorless cells; pal 1 and pal 2 pali- 
sade cells (see Fig. 166); a, b, c layers of inner brown coat of spermoderm; .V perisperm; 
E endosperm; aep outer epidermis of cotyledon with h? multicellular hair and sto 1 
stoma. X160. (Winton.) 

pressed (b and c). Brown coloring matter like that in the second layer 
of the spermoderm is usually present only in the cells of the outer layers. 
Owing to the absence of cell-contents in the inner obliterated cells, the 
inner surface of the spermoderm is more or less opalescent. 

Perisperm (Figs. 166 and 167, N). An exceedingly thin skin con- 
sisting of a single cell layer of perisperm and another of endosperm 
covers the embryo. The colorless perisperm cells are characterized by 
the fringe-like walls made up of threads perpendicular to the surface. 
Hanausek's name, "fringe cells," is very appropriate. 

Endosperm (Figs. 166 and 167, E). A single layer of moderately 


thick-walled cells containing small aleurone grains constitutes the endo- 

Embryo. After soaking for a day in water, the complicated folds 
of the cotyledons (Fig. 166, C) may be straightened out and their broad 
kidney shape noted. 

By scraping the cotyledons the epidermis (Figs. 166 and 167, aep) may 
be removed for examination. As was first noted by Hanausek, three 
kinds of cells are present: first, thin-walled polygonal cells; second, 
pairs of cells with curved walls, the guard cells of immature stomata (sto 2 ); 
and third, small cells continued beyond the surface in the form of oval 
hairs divided into several cells by cross partitions (h 2 ). The hairs are 
most abundant at the point of insertion on the axis. 

Sections of the cotyledons and radicle may be cut dry without remov- 
ing the spermoderm, although better sections are obtained after remov- 
ing the spermoderm and embedding directly in paraffine. 

In the outer portion of the mesophyl, the cells are isodiametric, 
in the inner layers, of typical palisade form. Procambium bundles (g) 
run longitudinally or obliquely through the mesophyl. 

Crystal clusters (k) occur in cells scattered here and there, but in 
most of the mesophyl cells aleurone grains and fat are the only visible 
contents. The aleurone grains (al) are 2-5 p. in diameter and are more 
or less angular or irregular in shape. Alkali dissolves the aleurone 
grains and other contents and imparts a deep-yellow color to the tissues. 

The so-called resin cavities of the cotyledons (s), containing a dark- 
colored secretion, appear to the naked eye as brown dots in the nearly 
colorless ground tissue. Around these cavities two or more indistinct 
rows of exceedingly thin, elongated cells (the mucilage cells of Hanausek) 
are arranged in concentric layers. 

We are indebted to Hanausek for the following observations: Ex- 
amined in water, the secretion is olive-green, flowing out of the cavities 
in the form of a yellow-green emulsion, the particles of which are in 
lively motion. Strong sulphuric acid dissolves the secretion to a beau- 
tiful blood-red solution. Alkalies color it green-brown, but do not dis- 
solve it. 


Undecorticaled Cottonseed Cake. It is customary in India, Egypt, and 
in most cotton-growing countries, except the United States, to express 
the oil without previous removal of the hulls. The cake obtained as a 
by-product in this process, although containing more fiber and less pro- 


tein than the decorticated cake, is preferred by the English feeders, be- 
cause of the mechanical action of the hulls. 

Samples should be mounted in water and examined first directly 
to detect possible starchy adulterants, and again after addition of alkali, 
noting the fragments of spermoderm and the yellow color of the dis- 
organized lumps. The coats of the spermoderm are best studied in 
fat- and protein-free material obtained by the crude-fiber process or 
by Hebebrand's method (p. 172). 

Especially characteristic are the thick- walled epidermal cells (Figs. 166 
and 167, ep) with hairs and the palisade cells (pal), although the other 
layers aid in identification. The fringe cells (N) of the perisperm are char- 
acteristic, but not so conspicuous as are the layers of the spermoderm. 

The cake or meal from common cotton contains more fiber (often 
attached to fragments of hull) and less abundant brown pigment in both 
the outer brown layer and the inner, than products of the varieties of 
G. Barbadense (Sea Island Cotton, Egyptian Cotton, etc.). Voelcker 
places considerable dependence on the more or less pronounced opales- 
cent appearance of the inner surface of the hulls of Bombay seed as dis- 
tinguished from the deep-brown inner surface of the hulls from Egyptian 
seed, a distinction which also holds good in most cases between upland 
and Sea Island seed as grown in the United States. This observation, 
first brought to notice by Richardson of Lincoln, England, depends on 
the degree of obliteration of the innermost cells of the spermoderm. 

Decorticated Cotton-seed Cake. In the United States, upland cotton 
seed is hulled before expressing the oil, the cake and the rich yellow meal 
obtained by grinding the cake consisting of material from the cotyledon 
with only a small amount of spermoderm. This meal is often grossly 
adulterated with ground cotton hulls, and occasionally with rice refuse. 
Finely ground hulls, owing partly to the fine state of division of the dark- 
colored m atter, and partly to the exposure of the nearly colorless palisade 
cells, is not so dark as the coarsely ground hulls and more readily escapes 
detection in the meal. 

Determinations of nitrogen and fiber, coupled with microscopic ex- 
amination of the original material and of the crude fiber, serve for the de- 
tection of this form of adulteration. 

Cotton Hulls formerly were burned as a fuel under" the boilers of 
the oil mills, and the ash, rich in potash, utilized as a tobacco fertilizer. 
They are now used for feeding cattle or as an adulterant of cotton-seed 
meal, as noted above. 



See General Bibliography, pp. 671-674: Benecke (2); Bohmer (6, 10, 23); Collin (8); 
Hanausek, T. F. (17, 48). 
V. Bretfeld: Anatomie des Baumwolle- und Kapoksames. Jour. f. Landw. 1887, 

35, 29. 
Hanausek, T. F.: Zur mikroskopischen Charakteristik der Baumwollsamen-Producte. 

Ztsch. allg. osterr. Apoth.-Ver. 1888, 26, 569, 591. 
Kobtjs: Kraftfutter und seiner Verfalschung, Landw. Jahrb. 1884, 13, 813. 
Voelcker: Methods of Discriminating between Egyptian and Bombay Cotton Seed 

Cakes. Analyst. 1903, 28, 261. 
Winton: The Microscopic Examination of American Cotton Seed Cake. Analyst. 

1904, 29, 44. The Anatomy of Certain Oil Seeds with Especial Reference to the 

Microscopic Examination of Cattle Foods. Conn. Agr. Exp. Sta. Rep. 1903, 175. 


Several tropical trees belonging to the order Bombacece have capsules 
filled with a dense mat of woolly hairs which spring from the endocarp, 
not as in the case of the cotton, a member of a closely related family, 
from the spermoderm. These hairs are too brittle to be of value as 
textile fibers, but are used for upholstery. Of these "silk-cotton trees" 
Java kapok (Ceibo pentandra (L.) Gartn., Eriodendron anfractuosum DC), 
and East Indian kapok (Bombax Ceiba L.) are of importance, not only 
for the fibers, but also for the oily seeds, which resemble cotton seeds 
in structure. In the Celebes the seeds are eaten by the natives, and in 
various countries are used for making oil. Two German authors, Reinder s 
and Kobus, state that the cake is an adulterant of linseed cake. 

The campylotropous seed is about the size of a pea and has a swollen 
funiculus which covers the chalaza. The cotyledons are folded simi- 
larly to those of the cottonseed, but do not have resin cavities. 


The following comparison of the structure of cotton and Java kapok 
seeds is given by v. Bretfeld : 

Cotton Seed. Kapok Seed. 


1. Epidermis: . sclerenchymatized with thin-walled with gland-like 

hairs; cavities. 

2. Outer Brown Coat: with nbro-vascular bundles; without fibro-vascular bun- 





3. Colorless Cells: 

4. Palisade Cells: 

5. Inner Brown Coat: 


Cotton Seed. 
1-2 cell layers; 

Kapok Seed. 

3-4 cell layers with crystal 
\ longer; $ shorter, 

more star cells; fewer star cells, 

cells smaller, walls more cells larger, walls less knotty. 

green tissue with resin colorless tissue without resin 

cavities; cavities. 


Bketfeld : Anatomie des Baumwolle- und Kapoksamens. Jour. Landw. 1887, 35, 29. 
Kobus: Kraftfutter und seiner Verfalschung. Landw. Jahrb. 1884, 3, 813. 
Van Pesch: Kapok-Kuchen. Landw. Vers.-Stat. 1896, 47, 471. 


Hemp {Cannabis saliva L. order Cannabinea) is grown as a fiber 
plant throughout Europe, especially in Russia, also in Africa, India, 
China, Brazil, the United States and other regions. 

When the production of fiber alone is considered, the plant is cut 
shortly after blooming; but in Russia it is allowed to grow until the fruit 
reaches maturity, thus securing a yield of seed as well as fiber. Indian 
hemp (Cannabis saliva var. Indica) is grown exclusively as a medicinal herb. 

The dicecious plant yields an oval, somewhat flattened, two-ribbed 
fruit, consisting of a brown pericarp delicately marked with white veins 
(Fig. 168, II and III, F), a spermoderm (5) of a green color, a thin endo- 
sperm, and a bulky embryo with thick cotyledons (C) and a radicle (R) 
bent parallel to the cotyledons. The "seeds" on the market consist, 
for the most part, of naked fruit, with an occasional fruit inclosed within 
the hooded calyx (Fig. 168, I). 


Calyx (Fig. 169). 1. Outer Epidermis (aep). From among the 
polygonal cells of the epidermis arise two very characteristic and striking 
elements: first, the glands, either sessile or stalked (d); and second, 
the cystolith hairs (h). The glands are globular with eight or more 
cells on the under side radiating, usually, from two central cells, the 
secretion cavity being formed by the separation of the outer cuticle 
from these cells. These glands are usually borne on many-celled stalks, 
often 300 ft long. The cystolith hairs are characterized by their irregu- 



larly globular bases, often 75 p in diameter, in which is suspended a 
cystolith of calcium carbonate (cy). They taper either abruptly or gradu- 


FlG. 168. Hemp (Cannabis sativa). I calyx. II outer surface of fruit. Ill longitudinal 
section of fruit. F pericarp; 5 spermoderm; E endosperm; C cotyledon; R radicle. 
X4. (WlNTON.) 

ally from this base to the pointed apex, in the latter case often reaching 
a length of 500 p. and sometimes 1 mm. The walls, although but one- 
half to one-sixth as thick as the lumen, are often 8 fi thick. 

2. Mesophyl (mes). Several layers of. small cells, through which 
run numerous bundles, make up the mesophyl. In the inner layer the 


Fig. 169. Hemp. Calyx in surface view, aep outer epidermis with h hair containing 
cy cystolith, and d glandular hair; mes mesophyl containing crystals; iep inner epi- 
dermis. Xl6o. (WlNTON.) 

■cells are about 10 fi in diameter and contain crystal clusters of calcium 



3. The Inner Epidermis (iep). Cells with wavy outline, thin-walled 
hairs, and stomata form the inner layer. 

Pericarp (Figs. 170 and 171). 1. Epicarp (ep). This layer consists 
of more or less sclerenchymatized cells with wavy outline. The radial 
walls are, in some parts, moderately thickened, in others so thick that 
there is but a narrow lumen. All the walls are porous. 

2. Spongy Parenchyma (hy). One or more layers of colorless cells, 
usually with numerous circular intercellular spaces, form a hypodermal 

Fig. 170. Hemp Seed. Cross section of fruit. F pericarp consists of ep epicarp, hy 
hypoderm, br brown cells, w dwarf cells, and pal palisade cells; 5 spermoderm consists 
of sch tube cells and J spongy parenchyma; N perisperm; E endosperm; C cotyledon 
with aep outer epidermis, and iep inner epidermis; al aleurone grains. X160. 

coat. Through this layer run the numerous anastomosing bundles, 
which, seen through the epicarp, are evident to the naked eye as veins. 
This layer is thickest in the two keels of the fruit. 

3. Brown Cells (br). Owing to their greater thickness and the presence 
of brown contents, these cells are more readily distinguished in cross 
section than those of the preceding layer. In preparations obtained by 
heating the fruit in alkali and scraping, they are conspicuous. Focusing 
on the outer wall, the radial walls are straight or moderately sinuous; 
but further inward they are zigzag with projections — often branching — 
extending into the cell cavity and forming in each cell what appear to be 
several indistinct compartments. The cell-contents, after this treatment, 
form irregular lumps shrunken away from the walls. 



4. Dwarf Cells (w). Owing to its thinness, this layer can be seen in 
cross section only in carefully cut specimens; but in tangential sections 

' ' ' Tgi 





FlG. 171. Hemp. Pericarp in surface view seen from without, ep epicarp; hy hypoderm 
with s/> spiral vessels; br brown cells; iv colorless cells; pal 1 palisade cells (see Fig. 170). 
X 160. (Winton.) 

or preparations obtained by the treatment above described, the minute, 
colorless, porous cells (seldom over 12 ji) with wavy, radial walls are 
readily distinguished. 

5. Palisade Layer {pal). This layer, owing to its thickness (often 
100 //), the peculiarly thickened porous walls, and the wavy outlines of 

Fig. 172. Hemp. Palisade cells, spermoderm, perisperm, and endosperm seen from 
within. paP palisade cells (see Fig. 170); sch tube cells and 5 spongy parenchyma 
of spermoderm; N perisperm; E endosperm. X160. (Winton.) 

the radial walls as seen both in cross and tangential sections, is the most 
conspicuous and characteristic of all the layers of the fruit. So strongly 
sclerenchymatized are the outer and, except at the inner end, the radial 
walls, that the lumen is reduced to a narrow line for fully two-thirds of 


the outer portion of the cell (pal x ); at the inner wall, however, the radial 
walls abruptly narrow, leaving a wide lumen (Fig. 172, pal 2 ). The 
inner wall is porous and moderately thickened. 

Spermoderm (Figs. 170 and 172, S). The cells contain green granules, 
which are insoluble in alcohol, ether, and alkali. 

1. Tube Cells (sch). The outer layer is quite distinct from the inner 
layer, owing to the elongated form of the cells and the elongated rows of 
intercellular spaces. 

2. Inner Layer (s). Further inward the cells form an indistinct 
spongy parenchyma with star-shaped or irregular cell outlines. 

Perisperm (Figs. 170 and 172, N). If the fruit is soaked for a day 
or two in 1 J per cent soda solution, the perisperm with adhering endosperm 
readily separates from the spermoderm on the one hand and the embryo 
on the other. In cross section it is indistinctly seen. 

The Endosperm (Figs. 170 and 172, E) forms a coat, mostly one cell- 
layer thick, about the whole embryo, and also extends in the form of a 
partition several layers thick between the cotyledons and the radicle. 
These cells, containing small protein grains, resemble the aleurone cells 
of the cereals. 

Embryo (Fig. 170, C). Both epidermal layers of the cotyledons are 
composed of small cells with aleurone grains 2-3 \i in diameter. Beneath 
the outer epidermis are several layers of isodiametric cells, while adjoin- 
ing the inner epidermis are two layers of typical palisade cells. Both 
forms of cells contain, in addition to fat, aleurone grains up to 8 ft. 
Each grain consists of an irregularly-spherical or elliptical body con- 
taining a crystalloid with a globoid excrescence. 


The seeds serve primarily for the production of oil ; but the cake from 
the oil presses is utilized in various parts of Europe as a cattle food, a fer- 
tilizer, and possibly as an adulterant. 

The characteristic elements are the epicarp (Fig. 171, ep), the spongy 
parenchyma (hy) with anastomosing bundles, the dwarf cells (w), the 
palisade cells (pal), and the tube cells (Fig, 172, sch) of the sper- 
moderm with green contents insoluble in alcohol, ether and alkali. 

Extraction with ether, and treatment by Hebebrand's method (p. 172) 
may be used to prepare material for examination. If sufficiently large 
fragments of the shell are obtainable, the palisade cells are best identified 


in cross section, and the dwarf cells in tangential section. The aleurone 
grains, if still intact, may be seen in turpentine mounts. 


See General Bibliography, pp. 671-674: Benecke (2); Bohmer (6, 10, 23); Collin (8); 
Hanausek, T. F. (17); Harz (18); Tschirch (39); Tschirch u. Oesterle (40). 
Macchiati: Sessualita, anatomia del frutto e germinatione del seme della canapa. 

Bull. d. Statione agraria di Modena, 1889, Nov. Ser. 9. 
Tschirch: Ueber den anatomischen Bau und die Entwickelungsgeschichte der Secret- 

driisen des Hanfes. Naturforscherversammlung, 1886- Ber. in Pharm. Ztg, 

1886, 31, 577. 
Winton: Anatomie des Hanfsamens. Ztschr. Unters. Nahr.-Genussm. 1904, 7, 385. 

The Anatomy of Certain Oil Seeds with Especial Reference to the Microscopic 

Examination of Cattle Foods. Conn. Agr. Exp. Sta. Rep. 1903, 175. 


Common sesame {Sesamum Indicum L., order Gesneracem) is one of 
the most valuable cultivated plants in India, China, Asia Minor, Palestine, 
Arabia, and other parts of the Orient, the 
seeds serving for the production of oil 
and cake, also for direct consumption as 
human food. The plant is also to some 
extent cultivated in Egypt, parts of East 
Africa, and in the warmer parts of North 
and South America. j jj 

The flattened pear-shaped seeds (Fig. fig. 173. Sesame Seed {Sesamum 
17 V) are 2-3 mm. long and vary in color indicum). / outer surface of seed. 

' J/ _ ^ ° J II transverse section, o spermo- 

from white to brown. Passing longitU- derm with I ridges and R raphe; 

j. n .i 1 ,i . j: r .r E endosperm; C cotyledon. X8. 

dinally through the center of one of the (Winton ) 
flattened sides, is the raphe (R), and run- 
ning around the edge of each of the flattened surfaces is an indistinct ridge 
conforming to the shape of the seed (/). The endosperm (£) is about 
half as thick as the cotyledon (C). 


Spennoderm (Fig. 174, S; Fig. 175). 1. Epidermis (ep). The cells 
throughout are radially elongated with convex outer walls. Owing to 
the thinness of the radial walls, they are usually collapsed, but assume 
their normal form on heating cross sections with dilute alkali. The cells 
forming the ridges are empty and, as was first noted by Benecke, are 


arranged like the vanes of a feather. In other parts the cells are parallel 
and each contains in the extreme outer end, adjoining the thin outer wall, 

E S 

Fig. 174. Sesame. Cross section of seed. 5 spermoderm consists of ep epidermal cells 
with Ca crystal masses, / epidermal cells of ridges, p parenchyma and m yellow mem- 
brane ; E endosperm ; C cotyledon containing al aleurone grains. X 1 60. (WiNTON.) 

an irregularly spherical mass consisting of calcium oxalate crystals (Ca), 
apparently within a thin membrane. These masses are 1 2-40 ft in diam- 
eter. In surface view, as may be clearly seen by examination of the skin 
which separates after boiling the seed in water, the crystal cells are iso- 
diametric -polygonal (ep), the cells of the ridges slightly elongated (/). 

Fig. 175. Sesame. Spermoderm and endosperm in surface view, ep epidermis with Ca 
crystal masses; I epidermal cells of ridges; E endosperm. X160. (Winton.) 

By boiling with alkali on the slide, some of the epidermal cells may be 
isolated and, after staining with chlorzinc iodine, viewed in a horizontal 


position. Sometimes the crystal masses are disintegrated, the separate 
crystals presenting the appearance shown in Fig. 175. 

2. Parenchyma (Nutritive Layer) (p). One, sometimes more, layers 
of collapsed cells, form what in the earlier stages of growth was a nutritive 
layer. Only after heating with alkali is the cellular structure at all 
evident in cross section and then but indistinctly. After removing the 
epidermis as above described and treating the seed with safranin or chlor- 
zinc iodine, colored fragments may be removed from the surface of the 
seed, which often show longitudinally elongated cells. Hanausek has 
noted that the cells contain loose crystals of calcium oxalate. 

3. Yellow Membrane (Fig. 174, m). Lining the inner surface of the 
spermoderm is a membrane, probably the cuticle of an obliterated inner 

Endosperm (Figs. 174 and 175, E). The outer wall of the endosperm 
is strongly thickened. At the ends of the elliptical cross sections there 
are but two cell layers, but on the sides there are three to five layers. 
The cells contain aleurone grains (2-6 fi), and fat. 

Embryo (Fig. 174, C). The cells of the cotyledons, except in the 
single layer of palisade cells, are isodiametric and like those of the endo- 
sperm, contain aleurone grains (up to 10 fi) and fat, but no starch. Hanau- 
sek states that each grain contains either a crystalloid or, at one of the 
poles, a globoid. 


Not only is sesame oil one of the most valuable of the vegetable oils, 
but the seed itself is an ingredient of various articles of diet throughout 
the warmer countries of the East, and the cake obtained as a by-product 
in the manufacture of the oil serves as food for both man and beast. 
Sesame cake has been imported into Europe in large amount, where it 
is highly esteemed by cattle feeders. 

Samples of sesame cake may be prepared for examination by Benecke's 
or Hebebrand's method or by simply boiling with ij per cent alkali. 
Previous extraction with ether is desirable. 

Characteristic of common sesame are radially elongated, thin-walled 
epidermal cells (Fig. 175, ep), each with a crystal mass (Ca) in the outer 
end. In black sesame (S. radiatum S. et T.) the masses are in the inner 
end of the cell, where the cell-wall is strongly thickened. 


See General Bibliography, pp. 671-674: Benecke (2); Bohmer (6, 10, 23); Collin (8); 
Hanausek, T, F. (17, 48); Harz (18). 


Benecke: Die verschiedenen Sesamarten und Sesamkuchen des Handels. Pharm. 
Centralh. 1887, 545. 

Hebebrand: Ueber den Sesam. Landw. Vers.-Stat. 1898, 51, 45. 

Kobus: Kraftfutter und seiner Verfalschung. Landw. Jahrb. 1884, 13, 813. 

Winton: The Anatomy of Certain Oil Seeds with Especial Reference to the Micro- 
scopic Examination of Cattle Foods. Conn. Agr. Exp. Sta. Rep. 1903, 175. 


The castor-bean plant (Ricinus communis L., order Euphorbiacece) is 
grown for its oily seeds, from which is obtained the castor-oil of commerce. 
Castor pomace, although not suited for use as a cattle food because of 
the highly poisonous ingredient "ricine," is a valuable fertilizer. As this 
material has repeatedly been consumed by animals with fatal results, 
its microscopic detection is sometimes desirable. 

The seeds are obovoid, slightly flattened, with markings like those of 
a tortoise shell. On one of the flattened sides the raphe is clearly evident, 
and at the base a prominent caruncle. The 
~ ei spermoderm is hard and exceedingly brittle; the 
endosperm is bulky; the cotyledons of the axial 
embryo are broad but thin. 


The Spsrmoderm (Fig. 176) consists of five 

distinct layers of which four are readily removed 

as a brittle shell. As noted by Collin, the three 

outer layers may be separated from the fourth by 

boiling with dilute alkali. The innermost layer 

remains attached to the seed after shelling. 

1. The Epidermis (Fig. 176, ep; Fig. 177) is 

section of outer portion characterized by the sharply polygonal, finely pitted 

dermis; s spongy paren- cells, some of which are colorless, others of a brown 

C a£Tade cells ^p^trm color ' hence the mottle d appearance of the seed. 
chymatized palisade cells. 2. Spongy Parenchyma (s) forms a layer several 

(MoELLER.) ceUs th . ck _ 

3. Thin-walled Palisade Cells (p) with dark contents are the elements 
of the third layer. In surface view the cells are polygonal or rounded, 
12-20 /x in diameter, and often have intercellular spaces at the angles. 

4. Sclerenchymatized Palisade Cells (P) constitute a layer 200 [i thick. 
The cell-walls are of a brown color and show distinct pores. At the 

Fig. i 76. Castor Bean {Ri- 
cinus communis). Cross 


outer ends the cell cavities are somewhat broader than at other parts- 
Seen in surface view, the cells are polygonal, 8-15 /* in diameter. 

5. Inner Layer. After removing the foregoing layers, the seed, on 
close examination, is seen to be enveloped by a thin white skin— the inner 
layer of the spermoderm. This consists of a colorless, thin-walled, more 
or less compressed parenchyma, several cells thick, and numerous fibro- 

Fig. 177. Castor Bean. Outer Fig. 178. Castor Bean. Aleurone grains of 

epidermis in surface view. endosperm. A in oil; B in iodine solution. 


vascular bundles. Crystal clusters and radiating groups of feather-like 
crystals are readily found in surface mounts. 

Endosperm (Fig. 178). By far the greater part of the reserve material 
of the seed, consisting largely of aleurone grains and fat, is in the endo- 
sperm. The aleurone grains are round, ellipsoidal, or egg-shaped, and 
frequently reach a diameter of 20 /j.. Each contains a large crystalloid 
and an excentrically located globoid. Rarely two or more globoids are 


Highly characteristic of this seed are the sharply polygonal, pitted 
epidermal cells (Fig. 177) of the spermoderm, some with, others without, 
brown contents, and the brown, sclerenchymatized palisade cells (Fig. 
176, P). The other layers of the spermoderm are also of some diag- 
nostic value. Numerous large aleurone grains (Fig. 178), each with a 
large crystalloid and a smaller globoid, are seen in turpentine or glycerine 


See General Bibliography, pp. 671-674: Bohmer (6, 10, 23); Collin (8); Hanausek, 
T. F. (48); Planchon et Collin (34); Tichomirow (38). 
Collin: Tourteau de ricin; ses dangers, ses caracteres anatomiques. Jour, pharm. 

chim. 1903. 
Gram: Om Frosskallens Bygning hos Euphorbiaceerne. On the structure of the 
spermoderm of euphorbiaceous seeds. Eot. Tidskrift. 1896. 20, 358. 


Geis: Note sur le developpemenl de la graine du Ricin. Ann. Soc. nat. Eot. 1861, 15^ 

5; 1862, 17, 312; 186-;, Se>. V. 2, 5. 
Kayser: Beitrage zur Entwicklungsgeschichte der Samendecken bei den Euphorbiaceen 

mit besonderer Eeriicksichtigung von Ricinus communis L. Ber. Pharm. Ges. 

1892, 2, 45- 
Pammel: On the Seed Coats of the Genus Euphorbia. Contributions from Shaw 

School of Bot. 1891, No. 8, 543. 
Schlotterbeck: Beitrage zur Entwicklungsgeschichte pharmakognostisch wichtiger 

Samen. Inaug.-Diss. Bern, 1896. 


The seeds of the candlenut tree (Aleurites triloba Forst., A. Moluc- 
cana (L.) Willd., order Euphorbiacece) yield a valuable oil used as food 
and in the arts. The tree is a native of the Moluccas and the southern 
islands of Polynesia, but is cultivated in tropical and subtropical regions 
of both the Old and the New World, including Florida and California. 

The fruit is nearly globular, 5-6 cm. in diameter, and has two locules, 
each containing a single dark-brown, chestnut-shaped seed about 30 
mm. in diameter, consisting of a hard spermoderm 2-5 mm. thick, a 
bulky endosperm, and in the axis of the endosperm a thin embryo 
with broadly heart-shaped, leaf-like cotyledons and a short radicle. 


Wichmann made a thorough microscopic study of candlenut seeds 
on the market in 1880, and found the structure in most details analogous 
to that of the castor-bean. His material, however, lacked tissues cor- 
responding to the epidermis and subepidermal layer of the castor-bean, 
and his observations as well as my own further indicate that such tissues 
may have been present in the original seed but were removed before 
reaching the market. 

Spermoderm (Fig. 179). 1. Thin-walled Palisade Cells (p). Al- 
though probably not the epidermis, this is the outermost layer of the 
commercial seed. The prismatic, thin-walled cells are colorless and 
filled with a granular mass of calcium carbonate. 

2. Sclerenchymalized Palisade Cells (P). These cells correspond in 
structure with the brown palisade cells of the castor-bean, but are 
characterized by their much greater height, which varies from 1.5 to 
over 2.5 mm. Both the porous walls and the cell-contents are of a 
brown color. 



3. Parenchyma (s). This layer is characterized by the narrow, greatly 
elongated pores of the cell-walls and the cystolith-like masses of calcium 
oxalate contained in the cells. The cells increase 
in size from without inward and have intercellular 
spaces at the corners. 

4. Compressed Cells form the inner layers. 
The Endosperm contains, in addition to oil, 

aleurone grains from 8-24 p. in diameter, similar to 
those of the castor-bean. A crystalloid is always 
present in each grain, also one to two globoids. 

Calcium oxalate occurs in crystal clusters in the 
cells but not in the aleurone grains. 

Embryo. The cells are smaller than those of 
the endosperm, but like the latter contain oil and 
aleurone grains. 


The cake is distinguished from castor-pomace 
by the greater height of both layers of palisade 
cells (Fig. 179). The colorless outer layer contains 
granules of calcium carbonate; the inner brown 
cells have amorphous contents. These latter often 
reach 2.5 mm. in length. The narrow, elongated 
pores in the parenchyma of the third layer are fig. 179. Candlenut 
more or less evident. Aleurone grains similar to (Aleurites triloba). 

Spermoderm in cross 

those of the castor-bean form a large part of the section, p thin- 

t ■ 1 walled palisade cells; 

material. p brown sclerenchy . 

POPPY-SEED. matized palisade cells; 

J spongy parenchyma. 

The poppy plant (Papaver somniferum L. order ( m oellee.) 

Papaveracea), a native of the Orient, is now 
cultivated in various parts of the Old and New 

Two distinct varieties are recognized, the 
white, and the black or blue. The white 
poppy is grown chiefly for the production of 
opium, the black for the seed, from which is 
expressed poppy oil. 
The anatropous seeds (Fig. 180), are very small, seldom over 1 mm. 
long, and kidney-shaped, one end being slightly broader than the other. 

I Q 

Fig. 180. Poppy {Papaver 
somniferum) . /seed. 77 em- 
bryo. X16. (Winton.) 



The hilum and chalaza are in a notch, connected by a short raphe, the 
chalaza being nearer the broad end of the seed. Under the lens the 

FlG. 181. Poppy Seed in cross section. 5 spermoderm consists of ep epidermis, k crystal 
layer, / fiber layer, q cross cells and n netted cells; E endosperm, contains al aleurone- 
grains. X160. (Winton.) 

surface is beautifully reticulated. The straight embryo is embedded in 
the bulky endosperm. 


Spermoderm (Fig. 181, S; Fig. 182). Cross sections are prepared 
after soaking the seed in water and may be cleared with chloral or alkali. 
After soaking the whole seed for about 24 hours in i£ per cent sodium 
hydrate solution, the first four layers readily separate from the fifth. 

Fig. 182. Poppy. Spermoderm in surface view, ep epidermis; k crystal layer; / fiber 
I layer; q cross cells; « netted cells containing pig pigment. X160. (Winton.) 

Subsequent treatment with hydrochloric acid dissolves out the calcium 
oxalate, and staining with chlorzinc iodine or safranin renders the outer 
layers more distinct. 


1. The Epidermal Cells (ep) are polygonal and of enormous size, 
corresponding to the network on the seed. As appears in cross section, 
the cells are collapsed except in the neighborhood of the radial walls. 
In surface view the radial walls are sinuous and thin, what are "often 
considered the thick dark walls of this layer being not the walls at all, 
but the ribs formed by the thickening of the second and third layers. 

2. Crystal Layer (k). On the ribs, the cells of this layer are more or 
less tangentially elongated, but between the ribs, are isodiametric and 
polygonal, the elongated cells having longer radial walls than the others, 
thus contributing to the formation of the ribs. They contain fine, granu- 
lar crystals of calcium oxalate. Meyer has demonstrated that the blue 
color is due to the interference of light by the crystals over the brown 
cells in the background, and is the same phenomenon as causes the ap- 
parent blue color of the sky and the iris of the eye. As soon as these 
crystals are dissolved in hydrochloric acid, the seed appears brown. 

3. Fiber Layer (/). The fibers of this layer are 15-40 [i broad and 
are parallel to the curved axis of the seed. Seen in cross section, this 
layer is thickest in the ribs, the walls throughout being distinctly thick- 
ened and stratified. In surface view they are rendered more distinct by 
chlorzinc iodine. 

4. Cross Cells (q). The fourth layer consists of moderately thick- 
walled, transversely elongated, pointed cells arranged side by side in 
rows. The walls are impregnated with a brown material. 

5. Netted Cells (n). Owing to the netted-veined, colorless walls and 
the presence of deep brown contents, these cells are particularly strik- 
ing. They are arranged transversely and are often side by side in rows. 
The cell-contents are insoluble in alkali and do not give the tannin re- 

Some authors designate the cells of this layer "pigment cells," not- 
withstanding the fact that in the white poppy they do not contain pigment. 

Meyer, Tschirch and Oesterle, Vogl, and Hanausek describe an inner 
layer of thin-walled cells, but this layer is not usually evident except 
in the vicinity of the hilum. 

The Endosperm (Fig. 181, E) contains aleurone grains up to 3 ft 
in the outer layers and 7 ft in the inner layers, each grain containing sev- 
eral globoids and crystalloids. 

Embryo. In the cotyledons there is only one layer of palisade cells, 
and these cells are only slightly elongated. The aleurone grains are 
like those of the endosperm. 



Poppy-seeds are used in bread and pastries; poppy-cake, the by- 
product in the manufacture of poppy-oil, is fed to cattle. 

The ground material should be examined directly, also after s"oaking 
successively in i\ per cent soda solution and hydrochloric acid, or 
after treatment by Hebebrand's method. Fragments consisting of the 
first four layers, showing the ribs, and separate fragments of the layer 
of netted cells with brown contents, are readily identified (Fig. 182). 


See Genera] Bibliography, pp. 671-674: Benecke (2); Berg (3); Bohmer (6, 10, 23)- 

Collin (8); Hanausek, T. F. (16, 17,48); Harz (18); Meyer, A. (27); Planchon'et 

Collin (34); Tschirch u. Oesterle (40); Vogl (45). 

Godfkin: Etude histologique sur les tegument seminaux des Angiospermes. Soc. 
d. Sci. d. Nancy, 1880, 109. 

Hockauf: Beobachtungen an Handelsmohnen. Chem. Ztg. 1903. 

Mach: Mohn und Mohnkuchen. Landw. Vers.-Stat. 1902, 57, 421. 

Meuniee: Les teguments seminaux des Papaveracdes. "La Cellule," Recueil de 
Cytologie et d'Histologie generate. 1891, 7, 377. 

Michalowski: Beitrag zur Anatomie und Entwicklungsgeschichte von Papaver 
somnijerum L., I Theil, Dissertation, Gratz, 1881. 

Tschirch: Entwicklungsgeschichtliche Studien. Schw. Woch. Chem. Pharm. 1897 
35, No. 17. 

Winton: The Anatomy of Certain Oil Seeds with Especial Reference to the Micro- 
scopic Examination of Cattle Foods. Conn. Agr. Exp. Sta. Rep. 1903, 175. 


Of the vegetable oils commonly used as foods or in the arts, olive 
oil is the only one derived from the flesh of a fruit {Oka Europea L., order 

Olives differ greatly in size and shape according to the variety. When 
ripe they are of a purple color. Morphologically the fruit is a drupe, 
corresponding in general structure to the peach and apricot. 


Ripe olives preserved in brine furnish suitable material for studying 
all the histological elements except the salt-soluble aleurone grains of 
the endosperm and embryo. After soaking several days in alcohol, the 
fruit flesh is sufficiently hardened to permit the cutting of sections. These 
should be soaked for a time in ether to remove fat. 

OLIVE. 229 

Pericarp. 1. The Epicarp (Fig. 183) consists of thick walled polyg- 
onal cells about 25 fi in diameter. This layer, .as well as the mesocarp, 
contains a purple pigment, which, as Hanausek first noted, becomes in- 
tensely red on addition of concentrated sulphuric acid. 

2. The Mesocarp contains so much oil, that a clear idea of its struc- 
ture can be gained only after extraction with ether. 

In the outer portion the thin-walled cells are isodiametric, but in 
the middle and inner portion they are radially elongated. Distributed 

Fig. 183. Olive;(0Zea Europea). Epicarp and two stone cells of the mesocarp, seen from 

beneath. (Moeller.) 

here and there among this thin-walled tissue are stone cells (Fig. 183) 
remarkable for their fantastic shapes and especially for the curious 
beaked, T- or Y-shaped excrescences, occurring at the ends and angles. 
Being colorless, the stone cells are not readily found in water mounts, 
especially if the oil has not been extracted; but on treatment with alkali, 
they are colored a bright yellow. 

3. Endocarp (Fig. 184, a, m, i). The oblong stone consists of a 
dense conglomerate of sclerenchymatized tissues forming an envelope 
about the seed 1-3 mm. thick. In cross sections prepared by grinding 
on a whetstone (p. 13), the curious forms and grouping of the stone 
cells are clearly evident. These stone cells, like those of the mesocarp, 
are colorless and diverse in form, although lacking conspicuous excres- 
cences. In the outer and middle layers, both elongated and isodiametric 



forms occur, the former extending in all directions; in the inner layers 
all the cells are transversely elongated. Most of them are thick-walled, 
with exceedingly narrow lumen; occasional cells, however, have lumens 
broader than the walls. 

An innermost layer (en) composed of compressed thin-walled paren- 
chyma cells lines the cavity. 

Spermoderm (Fig. 184). 1. The Epidermal Cells (ep) seen in sur- 
face view are highly characteristic, owing to their unequally swollen 

Fig. 184. Olive. Elements in surface view, p oil cells of mesocarp; a, m, i stone cells 
and fibers of endocarp; en inner layer of endocarp; ep outer epidermis of spermoderm; 
eo outer layer of endosperm; E and e parenchyma of cotyledon; sp spiral vessel. X160. 

and colorless walls. They are more or less elongated, often reaching 
a length of 300 fi. 

2. Parenchyma. Beneath the epidermis are several layers of thin- 
walled cells, through which ramify the numerous bundles. The cells 
in the outer layers are sharply.polygonal; those further inward are rounded; 
the innermost are compressed. Numerous crystals of various forms are 
the conspicuous contents. 
v The Endosperm (Fig. 184) makes up the bulk of the seed. 

1. The Outer Layer (ea) consists of irregularly polygonal cells. Both 
the outer walls and the outer ends of the radial walls arc greatly thickened, 
the latter, in surface view, showing distinct pores. 

2. Parenchyma. The remainder of the endosperm consists of thin- 
■walled parenchyma, containing fat and proteid grains. 

OLIVE. 231 

Embryo (E, e). Embedded in the axis of the endosperm is the straight 
embryo, with oblong cotyledons several times the length of the radicle. 
The cells are smaller and thinner-walled than those of the endosperm, 
although containing the same materials. 


Olive Pomace, consisting of the fruit pulp obtained as a by-product 
in the manufacture of olive oil, is used to some extent as a cattle food, 
and also as an adulterant. 

Characteristic of this pulp are the grotesque stone cells (Fig. 183) 
becoming bright yellow on the addition of alkali, and the purple pigment 
of the epicarp and mesocarp, which changes to an intense red on addition 
of sulphuric acid. 

Olive Stones are ground to a considerable extent in France as an 
adulterant for white pepper and other spices, and are shipped to other 
European countries, as well as to America. 

The stone cells (Fig. 184, a, m, i) are characterized by their colorless 
walls and contents, and by the bright yellow color produced by alkali, 
wrhile those of pepper are yellow and often contain a brownish material. 
Especially characteristic are the large epidermal cells (ep) of the spermo- 
derm with swollen walls. The outer layer of the endosperm (ea) is also a 
striking element, but like the last, can be found only after diligent search. 


See General Bibliography, pp. 671-674: Bohmer (23); Hanausek, T. F. (10, 16, 17); 
Macd (26); Moeller (29); Schimper (37); Villiers et Collin (42); Vogl (45). 

Also see Bibliography of Pepper, p. 509. 
Bottini: Sulla struttura dell'oliva. Nuov. giorn. bot. ital. 1889, 21, 369. 
Hanatjsek, T. F. : Ueber einige, gegenwartig im Wiener Handel vorkdmmende Gewiirz- 

falschungen. Ztschr. Nahr.-Unters, Hyg. 1894, 8, 95. 
ILandrin: Falsification du poivre a l'aide des grignons d'olive. Jour, phann. 10, 194. 


LEGUMES {Leguminoscs). 

Plants of this family are characterized morphologically by their pods 
which are dehiscent on both sutures, physiologically by their power of 
assimilating atmospheric nitrogen through the agency of micro-organisms 
residing in the root tubercles, and anatomically by the structure of the 
spermoderm and starch grains. ^ 

Most of the species of economic importance belong in the subfamily 
Papilionacece, so-called because of their butterfly-like flowers, of which 
the sweet pea is a type; a few species, however, including the genera 
Cassia and Ceratonia have more regular flowers and are classed in the 
subfamily Ccesal-piniecB. 

The reserve material of the seed in many species is" starchy, but in 
some species starch is absent, the reserve material being largely proteid 
matter or, in exceptional cases, cellulose. 

Microscopic Characters of Leguminous Seeds. 

Only the seeds of most legumes are of interest to the food micro- 
copist, but notable exceptions are the green pods of snap beans eaten 
as a vegetable, the dried saccharine husks of the carob bean, serving as 
food for man and beast, and the shells of the peanut used as an adulterant 
of foods. 

The Spermoderm (Fig. 186, S) in all the species of economic im- 
portance has three layers, of which the two outer are one cell thick and 
the third is several cells thick. An inner epidermis is seldom evident. 
The hilum in some species is more or less elongated, and pierced through 
its major axis by a narrow slit. 

i. The Palisade Layer {pal), or outer epidermis, is of great diag- 
nostic value, not only in determining that a leguminous product is present, 
but also in naming the particular legume. The cells are prismatic, with 
thick walls, and in all the common species except the peanut and tonka 
bean are much higher than broad. The lumen in the inner portion is 
broader than in the outer, where it is usually a mere line. 

On both sides of the hilum slit two layers of palisade cells are present 



(Fig. 185, p l „and p 2 ), while immediately beneath the slit in many species 
is a group of sclerenchyma cells with reticulated walls (Tri), which, 
according to Tschirch and Oesterle, probably serve to prevent the 
entrance of fungi. 

The "light line," a light-colored band of different refractive power 
from the rest of the layer, may be seen in cross section. This line varies 


Fig. 185. Pea (Pisum arvense). Cross section of spermoderm through nsp hilum slit. 
p palisade epidermis with double layer of cells on both sides of the hilum slit; x sub- 
epidermal layer expanding beneath the hilum into a cushion of cells in which is em- 
bedded Tri a cluster of porous sclerenchyma cells. (Tschirch and Oesterle.) 

in its breadth and distance from the outer surface according to the species, 
and is of some importance in diagnosis. 

In surface view the cells are sharply polygonal, and often show radi- 
ating lines, due to the pores separating the ribs which make up the 
thickened walls. Focusing on the outer surface it has a shagreen-like 
appearance due to the strips which make up the thickened walls (Fig. 

After macerating with hot alkali or grinding, the palisade cells be : 
come isolated and, owing to their rod-shaped form, assume a horizontal 

2. The Column Cells (sub) forming the subepidermal layer are com- 
monly hour-glass or I-shaped (Fig. 189) without evident contents, but 
in the common bean they are prismatic and contain well-formed crystals 
of calcium oxalate (Figs. 186 and 187). 


In some species the walls of the hour-glass cells are ribbed, giving 
them in surface view the appearance of a sunburst. 

3. Parenchyma (p), usually of the spongy type, forms several layers, 
.seen to advantage only in surface view. The character of the cells differs 
in different species and different layers of the same species. 

4. The Inner Epidermis when present, is of thin-walled cells. 
The Perisperm is commonly absent, and when present, as for ex- 
ample in the soy bean, is not of interest. 

The Endosperm in some species forms an obliterated layer (e.g. bean, 
pea, etc.), in others a dense, horny structure with thickened cell-walls 
(e.g. carob bean), and in others still a tissue with thick mucilaginous 
inner-cell membranes (e.g. fenugreek). 

Embryo (C). This is always relatively large and has large coty- 
ledons, while in seeds lacking a well-developed endosperm it makes up 
by far the greater part of the seed. The contents are protein matter 
and fat together with, in many species, starch. 

Leguminous starch (am) is characterized by the large ellipsoidal 
grains with elongated, more or less branching hilum, although in some 
species the forms of the grains are irregular, and in the peanut and tonka 
bean are normally globular. 

The hilum is indistinct in some species, but is brought out clearly by 
polarized light. 

Chief Characters. 

Of chief value in recognizing a leguminous seed are the thick-walled 
palisade cells, the subepidermal cells (usually hour-glass shaped) and, 
when present, the ellipsoidal starch grains with elongated hilum. 

The parenchyma of the spermoderm is usually spongy. An endo- 
sperm with thickened walls is present in some species. 

Analytical Key to Leguminous Seeds. 

A. Seed contains starch. 

(a) Starch grains evident without treatment with reagents or by direct treatment 
with iodine solution; seed not aromatic. 
* Starch grains globular, under 15 f- in diameter; palisade cells under 25 n high. 
1. Palisade cells in surface view over 25 p broad with beaded walls and 

broad lumen Peanut (Arachis hypogaea). 

** Starch grains ellipsoidal, over 15 [i long; palisade cells over 25 ft but under 
100 £ high. 
+ Palisade cells with flat outer ends. 

II Column cells prismatic containing aystals. 

23 6 LEGUMES. 

2. Palisade cells under 60 p high; column cells thin-walled with large 

crystals Common Bean (Phaseolus vulgaris). 

3. Palisade cells over 60 p high; column cells thick-walled with small 

crystals Spanish Bean (P. mulliflorus). 

II II Column cells hour-glass shaped without crystals, under 20 p high. 
4.*Starch grains irregularly ellipsoidal up to 40 p long. 

Common Pea (Pisum sativum, P. arvense). 

5. Starch grains irregularly ellpisoidal up to 90 p long. 

Adzuki Bean (Phaseolus Mungo, var. glaber). 

6. Starch grains regularly ellipsoidal up to 35 p long. 

China Bean (Vigna Catjang) . 
II || II Column cells hour-glass shaped without crystals, 25-35 p high. 

7. Starch grains irregularly ellipsoidal up to 65 p long. 

Lima Bean (Phaseolus lunatus). 
+ + Palisade cells with rounded or pointed outer ends. 

8. Palisade cells under 45 p high with light line up to 10 p broad. 

Lentil (Ervum Lens). 

9. Palisade cells 50-65 p high with light line 10-15 p broad. 

Vetch (Vicia saliva, V. villosa, V. hirsula>. 
*** Starch grains ellipsoidal, over 15 p long; palisade cells over 100 p high. 
+ Column cells in one layer, hour-glass shaped. 

10. Starch grains up to 40 p long Egyptian Bean (Dolichos Lablab). 

11. Starch grains up to 70 p long Horse Bean (Faba vulgaris). 

+ + Column cells in several layers, hour-glass shaped, simple in outer, com- 
pound in inner, layers. 

12. Starch grains up to 50 p long Jack Bean (Canavalia). 

**** Starch grains ellipsoidal over 15 p long; palisade cells variable in height 

(35-I2S rt- 

13. Palisade cells with rounded outer ends. . .Chick Pea (Cicer arietinum). 
(6) Starch grains evident only after treatment successively with a mixture of hot 

ether and alcohol and iodine solution; seed aromatic. 

14. Palisade cells over 50 p high, under 25 p broad, with dark contents; 

starch grains globular, under 10 p. 

Tonka Bean (Coumarouna odorala). 
B. Seed contains no starch, or only traces. 

(a) Palisade cells pointed; column cells ribbed; endosperm mucilaginous. 

15. Palisade cells 30-45 ^ high; column cells 15-45 m oroad. 

Alfalfa iM-di.a saliva). 

16. Palisade cells 60-75 /• high; column cells 30-75'^ broad; seed aromatic. 

Fenugreek (Trigonella Foenum-Gracum), 

17. Palisade cells 125-150 p high; column cells 35-75 P high. 

Astragalus (A. baliciis). 
(6) Palisade cells with flat or rounded outer ends; column cells not ribbed. 
* Palisade cells straight, under 100 p high. 

18. Palisade cells 50-60 p high, 6-15 p broad; column cells 35-50 p 

high; easily isolated Soy Bean (Glycine hispida). 


19. Palisade cells 60-75 P high, 3-7 ^ broad; column cells 16-25 J" high, 

endosperm with enormously thickened walls. 

Coffee Cassia (C. occidentalis). 
** Palisade cells straight, over 100 fi high. 

20. Palisade cells 150 /* high, blunt spindle-shaped after isolation in 

water Soudan Coffee (Parkia). 

21. Palisade cells 170-250 11 high, with swollen outer walls; endosperm 

with enormously thickened walls; brown wrinkled bodies in 
mesocarp, becoming violet on treating with alkali. 

Carob Bean (Ceratonia Siliqua). 
*** Palisade cells geniculate, over 100 ft high. 

22. Outer J of palisade cells straight; inner i geniculate with dark 

contents; epidermis of cotyledons porous. 

Yellow Lupine (Lupinus luteus). 

23. Outer § of palisade cells straight, inner J geniculate with colorless 

contents; light line 2-6 ,"; epidermis of cotyledon not porous. 

White Lupine (L. albus). 

24. Outer J of palisade cells straight, inner i geniculate with dark 

contents; light line narrow; epidermis of cotyledons porous. 

Blue Lupine (L. angustifolius). 


Beck: Die Samenschale einiger Leguminosen. Sitzb. K. K. Aka'd. zu Wien, 1878, 79. 
Chalon: La graine de Legumineuses. Mem. et Pub. Soc. Sci., Arts et Let. du Hainaut. 

1875, 55- 
Guignard: Embryogenie des Legumineuses. Ann. des Sc. nat., Bot. 1882, Ser. VI, 

Mattirolo e Buscalioni: Ricerche anatomofisiologiche sul tegumenti seminali delle 

Papilionacee. Reprint from Memorie Accad. Szienze Torino. Ser. II, 42, 1892. 
Nadelmann: Ueber Schleimendosperm der Leguminosensamen. Ber. deutsch. Bot. 

Ges. 1889, 248. 
Pammel: On the Structure of the Spermoderm of Several Leguminous Seeds. Bull. 

Torr. Bot. C. 1886, 17. 
Pammel: Anatomical characters of the seeds of Leguminoss, chiefly genera of Gray's 

Manual. Transact. Acad. Sc. St. Louis, 1899, 9, 91. 
Pfafflin: Untersuchungen iiber Entwicklungsgeschichte, Bau und Function der 

Nabelspalte und der darunter liegenden Tracheldeninsel verschiedener praktisch 

wichtiger Papilionaceen-Samen. Inaug.-Diss., Bern, 1897. 
Schips: Ueber die Cuticula und die Anskleidung der Intercellularen in den Samen- 

schalen der Papilionaceen. Ber. deutsch. bot. Ges. 1893, 11, 311. 
Schleiden: Beitrage zur Entwickelungsgeschichte der Eliitenteile bei den Leguminosen 

und iiber das Albumen, insbesondere der Leguminosen 1838. 
Scrobischewky: Recherches sur l'embryogfoie des Papilionacees. Bull. Congr. 

Internat. Bot. et Hortic. Petersburg, 1884, 207. 
VAN Tieghem: Observations sur la legerite" ct la structure de 1'embryon de quelques 

Legumineuses. Mem. de Soc. Sc. nat. de Cherbourg, 19. 



connoN BEAN. 

The larger part of the dried beans used as food in Europe and America 
are the seeds of Phaseolus vulgaris Metzger, now regarded by Wittmack 
as a native of tropical America. To the same species belong the edible- 
podded varieties— the so-called snap- or string-beans— also certain twining 
varieties cultivated for the seeds. 

The hemitropous seeds are more or less kidney-shaped, although 
the ratio of length, breadth and thickness varies greatly in the different 

Fig. i 86. Common Bean {Phaseolus vul- 
garis). Cross section of outer portion of 
seed. 5 spermoderm consists of pal pali- 
sade cells with / light line, sub subepi- 
dermal layer containing calcium oxalate 
crystals, and p spongy parenchyma; C 
cotyledon ; ep epidermis of cotyledon ; al 
aleurone grains; am starch grains. Xi6o. 

Fig. 187. Common Bean. Elements of 
spermoderm in surface view. p pali- 
sade cells; s subepidermal cells with crys- 
tals; m spongy parenchyma. X 300. 

varieties, some being nearly globular, others much elongated, and still 
others strongly flattened. In color they are white, black, red, brown, or 
mottled. The elliptical hilum is situated in the middle of one of the 
narrow sides. A narrow slit follows the major axis of the hilum, piercing 
the outer of the underlying tissues. Near one end of the hilum is the 
micropyle and near the other end is a small wart. The raphe enters 
the seed at a point near this wart. 



The seed consists of a large embryo closely covered by a thin, brittle 

Spermoderm. 1. The Palisade Cells (Fig. 186, pal; Fig. 187, p), as 
may be seen in cross section, are upward of 60 p. long, with a narrow light 
line adjoining the cuticle. In the outer portion the cavity is narrow, 
but broadens toward the inner end. The color of the bean is determined 
by the color of the contents of these cells. Beneath the hilum there are 
two layers of palisade cells, both of which are pierced by the hilum slit. 

2. The Column Cells (Fig. 186, sub; Fig. 187, s) in this species are not 
hour-glass shaped as in the pea and many other legumes, but are pris- 
matic without intercellular spaces. The walls are moderately thick, and 
swell considerably in water or alkali. Each cell contains one, or rarely 
two, large monoclinic crystals of calcium oxalate, which nearly fills the 
cavity. The presence of la^ge crystals in the column cells is characteristic 
of this species. Beneath the hilum this layer is absent. 

3. Spongy Parenchyma (Fig. 186, p; Fig. 187, m). The cells are 
largest and have the thickest walls in the outer layers. In the inner layers 
they have long, narrow arms and exceedingly thin walls. At the hilum 
this layer forms a thick cushion. 

Embryo. (Fig. 186, C; Fig. 188). The two large cotyledons form the 
bulk of the seed. Fat and proteins are present throughout, as is also 
starch, except in the epidermal cells. 

In the outer epidermis (ep) the cells are isodiametric, in the inner 
epidermis they are tangentially elongated as in the pea. 

The cells of the Mesophyl are large (often 100 ft), and have thick 
(4-9 n) walls with distinct pores. Intercellular spaces of moderate size 
occur at the angles. 

The starch grains vary up to 60 fi in length, the larger grains being, 
for the most part, ellipsoidal or kidney-shaped, seldom irregularly swollen 
as in the pea. A conspicuous, branching cleft, appearing black because 
of inclosed air, is almost always present. 


Beans usually reach the consumer whole, and therefore unadulterated. 

Bean Meal is a comparatively rare article of commerce, used chiefly 
as a cattle food. Coarsely ground beans have been employed as adul- 
terants of coffee, although less often than peas and other legumes. 

The starch (Fig. 186, am) is distinguished from pea-starch by the 


absence of irregularly swollen forms, and the presence of a distinct 
branching cleft in each large grain. The cell-walls of the endosperm 
are thick and conspicuously porous, whereas in the pea they are usually 
thinner and indistinctly porous. 

Bean Hulls serve as a cattle food and adulterant. In bean products 

Fig. 188. Common Bean. Cross section of cotyledon showing starch grains. X3°°- 


containing the hulls, the crystal-bearing column cells (Fig. 187, s) furnish 
a ready means of identification. 


See General Bibliography, pp. 671-674: Bohmer (6); Greenish (14); Hanausek, T. 
F. (10); Harz (18); Maci (26); Moeller (29); Tschirch u. Oesterle (40); Villiers et 
Collin (42); Vogl (45); Wittmack (10). 

Gulliver: On the crystals in the Testa and Pericarp of several Orders of Plants 
and in the other Parts of the Order of Leguminoseas. Monthly Micros. Jour. 1873, 

Haberlandt: Ueber die Entwicklungsgeschichte und den Bau der Samenschale bei der 

Gattung Phaseolus. Sitzb. d. k. k. Akad. zu Wien. 1877, 75, 33- 
Koehler: Erbsen, Bohnen, Wicken und deren Mullereiprodukte. Landw. Vers. -Stat. 

1901, 55, 401. 
Tschirch: Ueber Starkemehlanalysen. Arch. d. Pharm. 1884, 22, 921. 


Of the several varieties of Spanish bean (Phaseolus mulliflorus Willd.) 
in cultivation, the scarlet runner and Dutch case-knife bean are the best 
known. The scarlet runner is grown partly for the brilliant scarlet flowers, 
and partly for the flattened black and pink mottled seeds. The Dutch 
case-knife bean has white flowers and seeds. 



In histological structure these beans are much like the common bean, 
but the palisade cells are longer (60-75 f) an d the column-cells have 
thicker walls and contain smaller crystals. Although the column cells 
are prismatic without intercellular spaces, the radial walls are thickest 
in the middle and diminish in thickness toward both ends, the cavity 
being, as a consequence, hour-glass-shaped. The cell structure of the 
embryo and the starch grains are practically the same as in the common 


See General Bibliography, pp. 671-674: Harz (18); Tschirch u. Oesterle (40). 


The adzuki bean (P. Mungo var. glaber Roxbg.) is highly esteemed 
in Japan as food for man and has been introduced into the United States. 
Other varieties of this species are also cultivated in the East. 

The plant yields a seed 8-10 mm. long, of a rich wine color. 

Characteristic of this seed is the narrow, elongated hilum 2-3 mm. 



Spermoderm. 1. The Palisade Cells are 75 [i high, 6-15 n wide, and 
contain a reddish pigment. 

2. The Column Cells are hour-glass-shaped like those of the pea? 
They are 14-20 fi high and 8-20 ft wide. 

3. The Parenchyma is much the same as in the common bean. 
Embryo. The thin-walled cells contain larger starch grains than 

any other common legume (often 90 /*). In addition to the usual ellip- 
soidal grains, trefoil and irregular grains, such as occur in the pea, are 
numerous. Their large size serves to distinguish them from pea-starch 
and their form as well as size from other leguminous starches. 


The small seeded Lima or Sieva bean (Phaseolus lunatus L.) and 
the true or large-seeded Lima bean (P. lunatus var. macrocarpus Benth.) 
are natives of South America, but are grown throughout the Western 
Hemisphere, the seed being eaten as a vegetable either green or dried. 
The flattened white seeds of the true Lima bean are 20-25 mm - l° n g an d 
about half as wide. 



Spennodenn. i. The Palisade Cells are 60-80 /j. long and 12-20 [i 

2. Column Cells. These are quite unlike the column cells of the 
other members of this genus. Their hour-glass form distinguishes them 
from the corresponding cells of the common and Spanish bean, and 
their greater height (25-35 /0 from the last named and all the other 
species of Phaseolus here described. The cells are 14-35 f- wide. 

3. Spongy Parenchyma. The outer and innermost " layers contain 
small cells, the middle layers large cells. 

Embryo. The moderately thick-walled cells contain ellipsoidal, reni- 
form and trefoil-shaped grains, which are, on the average longer (up 
to 65 /<) and broader than in the common bean. 


See General Bibliography, pp. 671-674: Harz (18). 


The field pea (Pisum arvense L.) is grown both as a forage plant and 
for the production of mature seeds; the garden pea {P. sativum L.) 
only as a vegetable. 

Peas of the former species are smooth, nearly spherical, and of a 
buff color; those of the latter species are either smooth or wrinkled. 


The Spermoderm (Figs. 189-192) is thin and brittle. The structure 
at thehilum is shown in Fig. 185; in other parts it is as follows: 

1. The Palisade Cells (p) are 60-100 ,u high, a narrow light line 
immediately adjoining the cuticle. In the inner portion of each cell 
the cavity is broad and wavy in contour. 

2. The Column Cells (t), of typical hour-glass form, are conspicuous 
both in cross section and in surface view. They never contain crystals. 
On heating pieces of the hull with dilute alkali and pressing with the 
cover-glass, these cells may be isolated, the hour-glass form being espe- 
cially striking after this treatment. They vary up to 20 [i in height. 

3. Spongy Parenchyma (Fig. 189, m; Fig. 192). The cells decrease 
in size from without inward. 

Embryo. 1. The Epidermal Cells (Fig. 193, ep) of the cotyledons 



are tangentially elongated and arranged end to end in rows. They 
contain aleurone grains and fat, but no starch. 

2. The Parenchyma (Figs. 193 and 194), making up the remainder 
of the cotyledons, is composed of large cells with moderately thick, non- 
porous walls, with intercellular spaces 
at the angles. Usually, but not al- 
ways, the walls are thinner than in the 
bean and the intercellular spaces are 
larger, often extending from one angle 
to another. 

The Starch Grains (Fig. 193) are 
commonly smaller than in the bean 
(seldom over 40 //) and among ellip- 
soidal, reniform, and globular forms, 
occur many which are characterized 
by irregular, rounded protuberances. 
As a rule, comparatively few grains 
have distinct clefts. 

Fig. 189. Pea (Pisum arvense). Cross 
section of spermoderm. c cuticle; 
p palisade cells with * light line; t 
hour-glass cells of the subepidermal 
layer; m spongy parenchyma. X160. 


Whole Peas, as well as pea hay, are highly prized in many regions 
as cattle food. Roasted and flattened whole peas are used as substitutes 
or adulterants for coffee. 

Split peas, freed from hulls, are prepared for use in soups and other 
culinary articles. 

Pea Flour, because of its high nutritive value, is an ingredient of 
many dietary preparations for infants and invalids, as well as for soldiers 
and others requiring a nutritious and palatable food in a concentrated 

Many of the starch grains (Fig. 193, st) have irregular swollen pro- 
tuberances, a phenomenon of no little value in dis- 
criminating between this and bean-starch. The 
starch of the adzuki bean also displays this pecu- 
liarity. Clefts in the grains are indistinct or want- 
ing. The parenchyma of the cotyledons is seldom 
as thick as in the bean and shows much less dis- 
tinct pores. The individual cells are readily sepa- 
rated from one another through the middle 
lamella, especially after treatment with alkali. This latter treatment, in 

Fig. 190. Pea. Pali- 
sade cells in surface 
view showing the 
outer surface . X 300. 



the case of roasted peas, dissolves out the starch grains, leaving a char- 
acteristic skeleton of colored proteid material. 

Pea Hulls are utilized as a cattle food and an adulterant. A 

Fig. igi. Pea. Elements of spermoderm in surface view, p palisade cells; t hour-glass 
cells (subepidermal layer) ; e parenchyma. X160. (Moellee.) 

common coffee adulterant in the United States consists of pea hulls 
made into pellets with molasses and other ingredients. 

Fig. 192. Pea. Outer layers of spongy parenchyma, i intercellular space; s porous 
membrane at end of arm. (Moeller.) 

The elements of the hull may be studied in section (Fig. 189), or 
in surface view (Fig. 191) after scraping with a scalpel. Isolation of 


J 45 

the palisade and column cells is accomplished by judicious heating with 
dilute alkali and side wise pressure with the cover-glass. The column 
cells (/) are hour-glass in form, without crystals; whereas in the com- 
mon bean they are prismatic, with large crystals of calcium oxalate. 

Fig. 193. Pea. Cross section of cotyledon. 
ep epidermis, p parenchyma containing 
st starch grains. X160. (Moeller.) 

Fig. 194. Pea. Cotyledon tissues in sur- 
face view, ep epidermis; st starch pa- 
renchyma. X160. (Moeller.) 

The height of the palisade cells (60-100 [i) and column cells (up to 20 ji) 
is of importance in diagnosis. 


See General Bibliography, pp. 671-674: Bohmer (6, 23); Greenish (14); Hanausek, 
T. F. (10); Harz (18); Mace" (26); Moeller (29, 32); Tschirch u. Oesterle (40); Vil- 
liers et Collin (42); Vogl (45); Wittmack (10). 

Sempolowski : Ueber den Bau der Schale landwirthschaftlich wichtiger Samen. Landwu 
Jahrb. 1874, 3, 823. 


Lentils, the seeds of Lens esculenta Moench (Ervum Lens L.), have 
been used in Oriental countries as food for man since very ancient times. 
Esau sold his birthright for a mess of pottage made from this seed. At 
present the plant is cultivated chiefly in the countries bordering on the 

The Latin word "lens," meaning primarily lentil, was afterward 
applied by the philosophers to the biconvex magnifying glass because of 
its resemblance to the lentil in shape. The seeds are gray-brown or red 
in color and 5-7 mm. in diameter. The long and narrow hilum, as well 
as the micropyle and raphe, are on the narrow edge. 



The Spermoderm (Fig, 
same as in the pea. 

i. The Palisade Cells (Fig 

195, S) is 1 mm. thick with layers much the 

195, pal) are 45 ft high, 8 /* broad, have 
rounded outer ends, over which the cuticle 
is extended in the form of blunt-pointed 
papillae. A light line nearly 10 ft broad 
lies directly beneath the cuticle, but the 
remainder of the walls are yellow-brown. 

Fig. 195. Lentil (Lens esculenta). 
Outer portion of seed in cross sec- 
tion. S spermoderm consists of pal 
palisade cells with / light line, sub 
hour - glass cells (subepidermal 
1 layer) and p spongy parenchyma; 
c cotyledon with ep epidermis and 
am starch cells. X 1 60. (Winton.) 

Fig. 196. Lentil. Hour-glass 
cells (subepidermal layer) 
of spermoderm in surface 
view. X160. (Moeller.) 

2. The Column Cells (sub) of hour- 
glass form are 18-35 /* broad and 12- 
22 fi high. An irregular brown lump 
nearly fills each cell (Fig. 196). 
3. Spongy Parenchyma (p). The outer layers consist of very small 
cells without conspicuous intercellular spaces. In the middle layers the 

Fig. 197. Lentil Starch. X300. (Moeller.) 

cells are large, some of them containing a brown substance showing the 
reaction for tannins. 



Embryo (Fig. 195, C). The thin-walled cells contain starch grains 
(Fig. 197) somewhat smaller than those in the bean or pea, the largest 
being but 40 fi long. In form they are mostly ellipsoidal, although forms 
with irregular excrescences similar to those occurring in the pea, are not 


Ground lentils are distinguished from bean and pea products by the 
smaller diameter (maximum 8 /1) of the palisade cells (Fig. 195, pal), 
their rounded or blunt-pointed outer ends, and the broader light line. 
The starch grains (Fig. 197) are also smaller. 


See General Bibliography, pp. 671-674: Bohmer (6, 23); Greenish (14); Harz (18); 

Mace 1 (26); Moeller(29, 32); Tschirch u. Oesterle (40); Villiers et Collin (42) ; Vogl (45). 

Beck: Vergl. Anatomie der Samen von Vicia und Ervum. Sitzb. Wiener Akad. 1873, 77. 

Sempolowski: Ueber den Bau der Schale landwirthschaftlich wichtiger Samen. Landw. 

Jahrb. 1874, 3, 823. 


Varieties of Vigna Catjang Walp (V. Sinensis Endl., Dolichos Sinensis 
L.) are grown in the East for their seeds, and in the Southern States as a 
vegetable and for forage and manuring. 

Although known in America as the cow 
pea or black pea, the plant is more cor- 
rectly a bean, and the names China bean 
and black-eyed bean in vogue in Europe 
are more appropriate. 

Black, white with black eyes, yellow, 
red, brown, and mottled seeded varieties 
are in cultivation, the size of the some- 
what flattened, kidney-shaped seeds varying 
from 6-10 mm. 


The Spermoderm (Fig. 198) consists of: 
(1) a layer of palisade cells (pal) 60-75 I 1 
high and 6-18 fi broad;. (2) a layer of 
column -cells (sub) 9-15 [i high -and 9-25 fi 
broad; (3) several compressed layers of 
spongy parenchyma (p). 

Fig. 198. China Bean (Vigna cat- 
jang). Outer portion of seed in 
cross section. 5 spermoderm con- 
sists of pal palisade cells with I 
light line, sub hour-glass cells 
(subepidermal layer), and p spongy- 
parenchyma; C cotyledon with ep 
epidermis and am starch cells. 
X160. (Winton.) 



The Cotyledons (C) contain starch grains much like those of the 
common bean though somewhat smaller (maximum 35 /t). 


The China bean has smaller starch grains (Fig. 198, am) than most 
of the common legumes. Compared with the large grains of the Lima 
or the adzuki bean, this characteristic is especially marked. The 
spermoderm has much the same structure as in the last-named species. 
The column cells (sub) are hour-glass-shaped. 

See General Bibliography, pp. 671-674: Harz (18); Tschirch u. Oesterle (40). 


Numerous varieties of the soy or soja bean (Glycine hispida Maxim, 
Soja hispida Moench), natives of the Orient, are grown in China and 

Japan for the highly nutritious seed, and 
in Europe and America for forage as well 
as for the seed. 

The yellow, brown or black seed 
(5-10 mm.) in some varieties is nearly 
globular, in others slightly flattened and 


Marked features of the soy bean are 
the high column cells of the spermo- 
derm, the presence of an endosperm 
and the absence of starch in the coty- 

The Spermoderm (Fig. 199) is closely 
united with the layers of the endo- 

1. The Palisade Cells (pal) of this 

seed are of about the same height 

(50-60 ft) and diameter (6-15 fi) as 

those of the common bean and, like 

ve colored contents, according to the color 

Fig. 199. Soy Bean (Glycine hispi- 
da). Outer portion of seed in 
cross section. 5 spermoderm con- 
sists of pal palisade cells with / 
light line, sub hour-glass cells (sub- 
epidermal layer), and p paren- 
chyma; E endosperm consists of 
aleurone cells and compressed 
cells; C cotyledon, with ep epi- 
dermis and al aleurone cells. 
X160. (Winton.) 

the latter, may or may not ha 
of the seed. 


2. Column Cells (sub). This layer is of about the same thickness 
as the palisade layer, being thicker than in any of the other common 
legumes. The hour-glass or I-shaped cells are usually 35-50 ji high, 
but about the hilum they often reach 150 ,«. In width they vary from 
16-36 /1. Since the cells have a marked tendency to separate from the 
adjoining layers and from each other, isolated cells may usually be found 
in considerable numbers in surface mounts obtained by scraping the inner 
surface of the hull, or in the ground seed. 

3. The Spongy Parenchyma (p) is much compressed and presents no 
characteristic features. 

An Endosperm (E) consisting of a single layer of moderately thick- 
walled aleurone cells (15-45 fi) and obliterated cells, marks this seed as 
an exception among legumes. The aleurone cells as seen in surface 
view are rectangular or polygonal with protein contents. 

Embryo (C). The thin- walled cells contain large aleurone grains, 
sometimes 25 fi in diameter. Starch is entirely absent. 


The absence of starch, the presence of long (35-50 fi) I-shaped column 
cells (Fig. 199, sub) readily isolated from the surrounding tissues, and 
the presence of an endosperm layer (E), furnish ready means for the 
identification of this seed. 


See General Bibliography, pp. 671-674: Bohmer (6. 23); Harz (18); Moeller (29); 
Tschirch u. Oesterle (40). 

Hanausek, T. F. : Die Sojabohne. Irmischia II, 1882, No. 7, 44. 
Hanausek, T. F. : Ueber das Vorkommen von Starkemehl in der Sojabohne. Ztschr. 

allg. osterr. Apoth.-Ver. 1884, 474. 
Harz: Ueber den Starkegehalt der Sojabohne. Ztschr. allg. osterr. Apoth.-Ver. 

1885, 40. 
Trimble: The Soja Bean. Amer. Jour. Pharm. 1897, 69. 


Seeds of the Egyptian or hyacinth bean (Dolichos Lablab L., Lablab 
vulgaris Savi.) are much eaten in the Tropics. 

In macroscopic structure they are characterized by their flattened 
form and large hilum. 

2 5° 


Strongly developed in this species are: (i) The Palisade Cells, 125 ft 
or more high; (2) The Column Cells of hour-glass form, 35-55 11 high and 

of about the same width. The Spongy 
Parenchyma is not remarkable. The 
Starch Grains vary up to 40 fi in length. 


See General Bibliography, pp. 671-674: Harz 
(18); Tschirch u. Oesterle (40). 


The name bean, now largely applied 
to plants belonging to the genus Phaseo- 
lus, formerly was appiled almost exclu- 
sively to the varieties of Faba vulgaris 
Moench (Vkia Faba L.) of which the 
horse bean, also known as the broad or 
Windsor bean, is one of the best known 
examples. Beans of this species were cul- 
tivated by the ancient Egyptians, Tro- 
jans, Greeks, and Romans, as well as by 
the lake dwellers and other prehistoric 

It is not remarkable that so ancient 
Fig. 200. Horse Bean (Faba vulgaris). a plant should have numberless varieties 
Outer portion of seed in cross sec- w jd e ly different, especially as to the size, 

tion. o spermoderm consists of pal J * ' 

palisade cells with i light line, sub shape, and color of the seeds. The best 
Kfi^ySSScSg known varieties have slightly flattened 

don with ep epidermis and am starch se eds 8-12 mm. long and tWO-thirds as 
cells. X160. .(Winton.) . 

broad. The conspicuous elongated nilum 

is not on the side of the seed, but at one of the ends. 


Spermoderm (Fig. 200). The palisade and column cells are remark- 
able for their large size. 

1. The Palisade Cells (pal) are 150-175 ji long and 12-20 ,u broad. 
A light line 20-25 /t broad, directly beneath the cuticle, is distinguishable, 


although the whole outer half of the layer is colorless. The cell-walls 
of the inner portion are yellow-brown. 

2. Column Cells (sub). This layer has strongly developed cells, 
35-50 ft high and 35-60 p. broad. They are hour-glass-shaped with a 
cavity only slightly constricted in the middle. The walls are rather thick. 

3. Parenchyma (p). The outer layers are of large cells with few 
intercellular spaces; the middle layers are of similar cells with deep 
brown contents; the inner layers are of compressed spongy parenchyma. 

Embryo (C). The isodiametric cells, with non-porous walls similar 
to those of the pea, contain starch grains (am) up to 70 fi in length. 
Broadly ellipsoidal grains, many scarcely longer than broad, also irreg- 
ular forms, are common. The hilum is often indistinct. 


The enormous height of the palisade cells (Fig. 200, pal) and their 
broad light line, also the large column cells (sub), serve to identify this 
seed in powder form. Although the starch grains (am) are of large size, 
and more nearly circular in outline than in most common legumes, too 
much dependence should not be placed on this distinction. 


See General Bibliography, pp. 671-674: Bohmer (6, 23); Harz (18); Mace" (26); 
Tschirch u. Oesterle (40). 
Godfrin: Etude histologique sur les tegument seminaux des Angiospermes. Soc. d. 

Sci. d. Nancy. 1880, 109. 
Sempolowski: Ueber den Bau der Schale landwirthschaftlich wichtiger Samen. 

Landw. Jahrb. 1874, 3, 823. 


The spring vetch or tare (Vicia saliva L.) has been cultivated since 
prehistoric times both for green fodder and seed, the latter being used 
to some extent for human food. The tare of the scriptures- is not this 
plant, but darnel (Lolium temulentum). 

Seeds of the spring vetch are dark colored, nearly globular, and 5 mm. 
or less in diameter. 


The Spennoderm of the vetch and lentil are much alike in structure. 
1. The Palisade Cells are characterized by the rounded or blunt- 
pointed outer ends, the thick cuticle, the broad light line (10-15 /j.) and 


the dark color and moderate thickness of the walls in the inner portion 
of the layer. They are 50-65 pt high and 6-10 ,u broad. 

2. The Column Cells (13-25 n high, 22-40 ,u broad) are hour-glass- 
shaped and contain a dark material. 

3. Parenchyma. This tissue is not spongy, but true parenchyma 
without marked intercellular spaces. The middle layers contain a dark, 
tannin-like material. 

Embryo. The non-porous walled cells contain ellipsoidal and irregu- 
larly-shaped starch grains each with a more or less distinct cleft. 


Both the lentil and vetch have palisade cells with rounded or blunt- 
pointed .outer walls, but in the latter seed these cells are somewhat higher 
and have a broader light line (10-15 fi). 


See General Bibliography, pp. 671-674: Bohmer (6); Harz (18); Mace (26); 
Tschirch u. Oesterle (40). 
Beck: Vergl. Anatomie der Samen von Vicia und Ervum. Sitzb. Wiener Akad. 1873, 

Sempolowski: Ueber den Bau der Schale landwirthschaftlich wichtiger Samen. Landw. 

Jahrb. 1874, 3, 823. 


The winter or hairy vetch (Vicia villosa Roth.), like the spring vetch, 
is a common forage plant in Europe and parts of 
the East. 

Although the seeds are somewhat smaller than 
those of the latter plant, they have practically the 
same structure. 


See General Bibliography, pp. 671-674: Bohmer (23); Harz 


Among the leguminous plants infesting Euro- 
Fig. 201. Hairy Vetch P ean S ram nelds tne hairy vetch (Vkia hirsuta Koch) 

fruittranchf ^'seed? is one of the commones t> *e seeds often occurring in 
natural size; c and considerable quantity in the grain. 
(Nome.) *" "^ ' Tne seeds are globular, about 2.5 mm. long, with 
dark spots on a somewhat lighter field (Fig. 201). 
The palisade cells are about 50 fi high, the spool-shaped column 


2 53 

cells about 15 fi. Starch grains up to 30 fi long fill the cells of the coty- 


See General Bibliography, pp. 671-674: Vogl (45). 


Lupines are cultivated chiefly for forage or green manuring, 
parts of Europe the seeds are used for hu- 
man food, and especially as a substitute 
for coffee. 

The common yellow lupine (Lupinus 
luteus L.) has a flattened, kidney-shaped 
seed 6-9 mm. long and 5-7 mm. wide, 
with black spots on a light background. 
The round hilum is - not situated in the 
cove, but in the center of one of the lobes. 


Spermoderm (Fig. 202, S; Fig. 203). 
1. The Palisade Cells (Fig. 202, pal; Fig. 
203, p) are 140-170 (i long and 8-18 fi 
broad, with rounded outer ends. The 
roughened cuticle is 3-6 /i thick and the 
narrow underlying light line 2-6 /1 broad. 
The outer portion of each cell for two- 
thirds its entire length has straight walls 
and a narrow cavity; the inner portion 
has two slight bends in opposite direc- 
tions. Those cells lying underneath the 
dark-colored spots on the surface of the 
seed contain a dark substance situated 
chiefly in the inner portion of the cavity. 

2. The Column Cells (Fig. 202, sub; 
Fig. 203, t) are 35-70 fi high, 25-50 /j. 
broad, hour-glass- or spool-shaped, much 

3. Parenchyma (Fig. 202, p; Fig. 203, 
and middle layers are sharply polygonal 
which appear distinctly beaded in surface 
up the inner layers. 

but in 

Fig. 202. Yellow Lupine (Lupinus 
luteus). Outer layers of seed in 
cross section. 5 spermoderm con- 
sists of pal palisade cells with I 
light line, sub hour-glass cells (sub- 
epidermal layer), and p spongy 
parenchyma with jv fibro-vascular 
bundle; C cotyledon with ep epi- 
dermis and al aleurone cells. X160. 

constricted in the middle. 

sch). The cells in the outer 
with thin, finely-porous walls, 
view. Compressed cells make 



Embryo (C). As noted by Bohmer, the outer epidermal cells of 
the cotyledons are finely porous; these pores, however, are confined 
to the radial walls and the edges of the tangential walls. 

The remainder of the cotyledons consists of Isodiametric cells with 
much swollen, porous walls, often 15-25 n thick. This thickening is 
especially marked at the angles. Ovoid aleurone grains up to 20 n, often 
containing large crystalloids, are the only visible cell-contents. Starch 
is entirely absent. 


All the common lupines have high palisade cells (Fig. 202, sub), 
geniculate in their inner portions, hour-glass-shaped subepidermal cells 

Fig, 203. Yellow Lupine. Elements of spermo- Fig. 204. Yellow Lupine. Collen- 

derm in surface view, p palisade cells; t hour- chyma cells of cotyledon with aleu- 

glass cells (subepidermal layer) showing contour rone grains, p porous wall. X 300. 

of base and constriction; sch spongy paren- (Moeller.) 
chyma. X160. (Moeller.) 

{sub) and thick-walled cotyledon cells containing aleurone grains (al), 
but no starch. 

In the yellow lupine, the outer two-thirds of each palisade cell (Fig. 
202, pal) is straight (distinction from blue lupine), and the inner genic- 
ulate portion often contains dark contents (distinction from white 
lupine). The sharply polygonal cells in the outer layers of the paren- 
chyma of the spermoderm, as well as in the epidermis of the cotyle- 
dons, are distinctly porous (distinction from white lupine). 


See General Bibliography, pp. 671-674: Bohmer (23); Harz (18). 
Sempolowski: Ueber den Bau der Schale landwirthschaftlich wichtiger Samen 
Landw. Jahrb. 1874, 3, 823. 



The white-flowered lupine (Lupinus albus L.) has light-colored, 
flattened, almost lenticular seeds somewhat larger (often 10 mm.) than 
those of the yellow and blue species. A depression is present in the 
center of each of the flat sides. 


The palisade cells and column cells are of the same size and structure 
as those of the yellow lupine, except that the light line of the palisade 
cells is broader (15-20 ft) and the contents are colorless. The cells of 
the spermoderm and the outer epidermis of the cotyledons are not evi- 
dently porous. 


See General Bibliography, pp. 671-674: Harz (18); Moeller (29); Vogl (45). 
Godfetn: Etude histologique sur les tegument seminaux des Angiospermes. Soc. d. 

Sri, d. Nancy. 1880, 109. 
Sempolowski: Ueber den Bau der Schale landwirthschaftlich wichtiger Samen. 
Landw. Jahrb. 1874, 3, 823. 


The type of Lupinus angushjolius L. has mottled seeds; the variety 
leucospermus, white seeds. Both have blue flowers. The seeds are 
rounded reniform, 5-7 mm. long. 


The structure corresponds with that of the yellow lupine, except as 
regards the palisade layer, which has a distinct line of demarcation a 
little less than half way between the outer and inner end. In the outer 
portion the walls are straight, of even texture, and the cavity is without 
contents; in the inner portion the walls are geniculate, of uneven tex- 
ture, and the ragged cavities contain a dark material near the line of de- 
marcation. The light line is narrow, as in the yellow lupine, but the 
outer end of the cell is not rounded. 


See General Bibliography, pp. 671-674: Hanausek, T. F. (10); Harz (18); Vogl (45). 
Gundriser: Ueber ein Kaffeesurrogat aus den Samen der blauen Lupine (Lupinus 

angustifolius). Ztschr. Nahr.-Unters. Hyg. 1892, 6, 373. 
Sempolowski: Ueber den Bau der Schale landwirthschaftlich wichtiger Samen. 

Landw. Jahrb. 1874, 3, 823. 




The East Indians prepare from the seeds of the chick pea {Cicer 
arietinum L.) various articles of daily food, as also do the Spanish and 
French; the inhabitants of Southern Europe and of some of the Western 
States of the United States utilize them as a substitute for coffee. 

Cicer is the old Latin name, and the English "chick" is a corruption 
of the same word, although suggesting the resemblance of the seed to a 

Fig. 205. Chick Pea (Cicer arietinum). Cross section of 
spermoderm. pal palisade cells; sub hour-glass cells 
(subepidermal layer); p spongy parenchyma. X160; 

Fig. 206. Chick Pea. Pali- 
sade cells in surface 
view. X160. (Moel- 

chick. The specific name "arietinum" was adopted because of the 
imagined resemblance of the seeds to a ram's head. 

The irregularly-globular seeds vary from 7-14 mm. in diameter, and 
from light buff to dark brown in color. They are encircled on one side 
by a groove, through the middle of which passes the raphe, and on the 
other by a ridge ending in a pointed projection at the micropyle. A cir- 
cular hilum 1 mm. in diameter is situated at the base of this projection. 


Spermoderm (Fig. 205). 1. The Palisade Cells are characterized by 
their variable length (35-125 //) and by their broad lumens (Fig. 206), 
the walls being thickened only at the extreme outer and inner ends. The 
thin radial walls are finely wrinkled toward the inner end. The cells 
are 12-20 n broad. 

2. The Column Cells are hour-glass-shaped, 20-30 // high and 25-45 ft 

3. The Parenchyma is much the same as in the common pea. 



Embryo. The isodiametric cells of the embryo also resemble those 
of the common pea. They contain broadly ovoid, sometimes nearly 
globular, starch grains up to 35 /x in length. 


.The irregular height and thin walls of the palisade cells (Fig. 205, 
pal) suffice for the detection of this seed. 


See General Bibliography, pp. 671-674: Harz (28); Moeller (29); Tschirch u. 
Oesterle (40); Villiers et Collin (42); Vogl (45). 


The negroes in Soudan and other parts of Africa prepare from the 
seeds and other parts of Parkia Africana R. Br. various articles of diet, 

Fig. 208. Soudan Coffee. Ele- 
ments of spermoderm. C iso- 
lated palisade cells; qu palisade 
cell in end view; m paren- 
chyma; ep inner epidermis. 
X160. . (Moeller.) 

Fig. 209. Soudan Cof- 
fee. Tissues of cot- 
yledon. X 160. 

Fig. 207. Soudan Coffee 
{Parkia Africana). 
Spermoderm in cross 
section, p palisade cells ;_ 
5 hour-glass cells (sub- 
epidermal layer); m 
parenchyma. X160. 

including a substitute for coffee. P. Roxburgii Don. is said to be a 
valuable food plant in the Indian Archipelago. 


Spermoderm (Fig. 207). The intercellular substance of the Palisade 
Layer is dissolved by soaking in water and the cells (150 fi high and 15 // 
broad) are liberated. After this treatment the isolated cells are char- 
acterized by their blunt, spindle-shaped form (Fig. 208, C). 


Both the Column Cells and the Spongy Parenchyma have thick walls. 
The Embryo (Fig. 209) is thin-walled and contains protoplasm and 
fat, but no starch. 


Examined in water the blunt spindle-shaped palisade cells (Fig. 208, 
C), the thick-walled column cells and spongy parenchyma (m), and the 
thin-walled cells (Fig. 209) of the starch-free embryo, are the important 

See General Bibliography, pp. 671-674: Moeller (29). 


Several tropical and subtropical species of Canavalia yield edible seeds, 
the most important being C. ensijormis DC. and C. obtusijolia DC. Both 
are used as coffee substitutes. 

The Jack bean or Chickasaw Lima (C. ensijormis) is grown to some 
extent in the southern part of the United States both for human food and 
feeding stock. 

The ovoid beans (15 mm. long) are white with a red eye about the 
long (5-7 mm.) hilum. 


Spermoderm. 1. The Palisade Cells are nearly colorless, 125-150 n 

&&. high and 10-22 /( wide. Their great height distin- 

t vll^. g uishes ^em from the palisade cells of species of 

^^^M Phaseolus. The thin cuticle when separated bears the 

t ^;J impressions of the cells beneath ^Fig. 210). 

\ ; 2- The Column Cells (Fig. 211) over the body of the 

I jj| I seed are in four or more layers and beneath the hilum 

/ ,*'\*1 f()rm a spongy mass upwards of 2 mm. thick. Those 

\ u 'V / in the first layer are 25-45 /t high and 25-60 fi broad. 

F.g. 210. jack Bean In the inner la y ers one finds a11 transitions from typical 
(Canavalia ensi- hour-glass cells, to fantastic compound or branching 

jormis). Cuticle ( , . 6 

with imprint of lorms sucn as are shown in Fig. 211, and finally to 
(MoelleI? 6 ) CeUS ' Parenchyma. Brown contents are present in the cells 
beneath the hilum. 

3. Parenchyma. This layer presents no remarkable features. 

Embryo (Fig. 212). The moderately thick-walled, porous cells of the 


2 59 

cotyledons, containing ellipsoidal starch grains up to 50 fi, recall the 
corresponding tissue of the common bean. 


Identification, whether in coffee or other food products, is not usually 
difficult, owing to the great height of the palisade cells and the several 

Fig. 211. Jack Bean. Subepidermal cells 
of spermoderm. X160. (Moeller.) 

Fig. 212. Jack Bean. Cotyledon tissue 
showing i intercellular spaces and / sec- 
tion of cell arm. X160. (Moeller.) 

layers of column cells (Fig. 211). The starch (Fig. 212) is of much 
the same size and form as that of the common bean. 

See General Bibliography, pp. 671-674: Moeller (29). 


Seeds of fenugreek (Trigonella Foenum-Graecum L.), remarkable alike 
for their curious shape, aromatic odor, and anatomical structure, have 
been employed as a drug both in human and veterinary practice for many 
centuries, especially in India, Asia Minor, Egypt, the Barbary States, 
and Southern Europe. They are also used as food by the women of 
Northern Africa to give plumpness to their forms. 

The outline of the slightly flattened, brown seed is quadrilateral, 
and the form of both the cotyledons and radicle is clearly evident on 
the exterior (Fig. 213). The radicle is bent parallel to the cotyledons 
and the longer axis of the seed (Fig. 214). Under a lens, the hilum is. 
seen to be situated near the apex of the radicle. 



Cross-sections, cut after soaking the seed in water, show a spermo- 
derm, a well-developed endosperm, and an embryo, both the latter being 
free from starch. 

Fig. 213. Fenugreek (Trigonella Foenum-Graecum). Fig. 214. Fenugreek. Seed with 
a seed, natural size; the others enlarged. spermoderm partially removed 

(Nobbe.) showing cotyledon and radicle. 


The Spermoderm (Fig. 216, 5; Fig. 215) has the three layers of a 
typical legume. 

Fig. 215. Fenugreek. Elements of seed in surface view, cut cuticle and blunt palisade 
cells; pal pointed palisade cells; sub subepidermal cells and parenchyma; a aleurone 
cells of endosperm. (Tschirch.) 

. i. The Palisade Cells (Figs. 215 and 216, pal), 60-75 J" high and 
8-20 n broad, have narrow cavities in the outer, broad cavities in the 





inner portions. On the outer surface the side walls are continued into 
pointed or, less often, blunt ends 8-20 fi long, projecting into an outer 
mucilaginous coat, the latter being indistinct in water and entirely in- 
visible on the addition of alkali. The cells with blunt ends are higher 
than the pointed cells. A narrow light 
line 3-6 [i is situated 25-35 V- fr° m 
the outer ends of the cells. 

2. The Column Cells (Figs. 215 and 
216, sub), although but 15-20 fi high, 
are quite as remarkable as the palisade 
cells. They are hour-glass-shaped, but 
the inner end is much broader than 
the outer. Particularly striking are the 
ribs, which may be seen either in cross 
section or in surface view, in the latter 
case presenting a beautiful radiating 
effect. Their great breadth, 30-75 ft, is 
a notable feature. 

3. Parenchyma (Fig. 216, p) with 
wavy walls and occasional intercellular 
spaces completes the spermoderm. 

An Endosperm (Fig. 216, E), glassy 
when dry, mucilaginous when wet, 
makes up nearly half the volume of 
the seed. 

1. Aleurone Cells (Figs. 215 and 
216, a). A single layer of cells (15-45 
fi) containing small aleurone grains 
envelops the embryo, and extends also 
between the cotyledons and the radicle. 

2. Mucilage Cells (muc). Tschirch 
has shown that each cell has a very 
thick mucilaginous inner membrane, 
glycerine slowly to a water preparation, 
only the thin primary membrane is evident 

Embryo (C). The hard yellow cotyledons and radicle contain aleurone 
grains (al) but no starch. Usually three layers of palisade cells underlie 
the inner epidermis. 

Fig. 216. Fenugreek. Seed in cross 
section. S' spermoderm consists of 
pal palisade cells with cut cuticle and 
I light line, sub subepidermal layer, 
and p parenchyma; E endosperm con- 
sists of a aleurone cells and muc mu- 
cilage cells; C cotyledon, with ep 1 and 
ep 2 epidermal layers and al aleurone 
cells. X160. (Wdjton.) 

which is evident on adding 
In sections mounted in water 
The cells appear to be 



Fenugreek is a common ingredient of condimental cattle foods and 
condition powders, where it is recognized by its characteristic taste and 

The high, pointed palisade cells (Figs. 215 and 216, pal) with 
mucilaginous outer membranes {cut), the ribbed column cells (sub), 
and the aleurone cells (a) are all easily found in fragments of the hull. 
Starch is absent throughout. 


See General Bibliography, pp. 671-674: Harz (18); Hassall (19); Meyer, A. (27); 

Moeller (31); Planchon et Collin (34); Tschirch (39); Tschirch u. Oesterle (40). 

Godfetn: Etude histologique sur les tegument seminaux des Angiospermes. Soc 
d. Sci. d. Nancy. 1880, 109. 

DE Lanessan : Sur la structure des graines du Trigonella Foenum Graecum et la pre- 
sence d'un albumen dans ces graines. Bull, de la soc. Linn, de Paris seance du 4 
juillet 1877, 134. 

Sempolowski: Ueber den Bau des Schale landwirthschaftlich wichtiger Samen. 
Landw. Jahrb. 1874, 3, 823. 


Seeds of coffee cassia or Mogdad coffee (Cassia occidentalis L.) are 
raised in parts of Africa, the East and West Indies, and other tropical 
regions as a substitute for coffee. 

Although a legume, the seed in external appearance does not resemble 
at all those of any other common member of the family. It is flattened 
obovoid, 4-6 mm. long, 3-4 mm. broad, its shape reminding one of the 
sesame seed. Its color is dark gray. An elliptical spot on the middle of 
each flattened side is dull and lusterless; the remainder of the surface 
however, is lustrous, owing to an enamel-like coating, which readily 
flakes off from the dry seed. The embryo, consisting of two thin but 
broad heart-shaped cotyledons and a short, straight radicle is em- 
bedded in a horny endosperm. 


After soaking in water for 24 hours, the outer coats form a slimy 
mass, which can be separated for study in surface view. The soaked 
seed also serves for cutting sections of the endosperm and embryo, but 
the dry or partially swollen seed is better suited for sections of the outer 



The Spermoderm (Fig. 217) is closely united with the endosperm. 

1. Palisade Cells (p). These are 60-75 F high an( i 3~7 P broad, 
the breadth being less than in most members of the family. A striking 
characteristic is the cuticular membrane, which is not a cuticle proper, 
but is made up of the metamorphosed outer portions of the palisade cells. 
Cross sections show that in the elliptical spots already mentioned this 
cuticular membrane is 30-35 n thick, or nearly half the height of the 
cells, though in other parts it is only about 1 2 y.. That it is derived from 
the cells proper is indicated by the faint markings perpendicular to the 

Fig. 217. Coffee Cassia (Cissii occiden- 
talis). Elements of spermoderm. p pali- 
sade cells in surface view; c isolated 
cells; cp cuticular plates; s subepidermal 
cells. (Moeller.) 

Fig. 218. Coffee Cassia. Cells of endo- 
sperm with brown contents. X160. 

surface, which correspond lo the radial walls of the inner portion of 
the layer. These are more distinct in the broader portion of the 
membrane. The enamel-like scales (cp) which separate from the dry 
seed consist of this membrane, although over the spots the fusion is 
more complete and no such separation takes place. The light line is 
confined entirely to the inner portion of the layer, being most distinct 
beneath the thick portion of the cuticular membrane. About two-thirds 
of the distance from the line of separation of the cuticular membrane to 
the inner surface of the layer there is noticeable a line of demarcation, 
caused by the presence of dark contents in the cell cavities, which are 
there somewhat inflated. In surface view the membrane displays peculiar 
zigzag walls. Moeller was the first to call attention to the disintegra- 
tion of the palisade cells through swelling, which takes place after soaking 
for a day or two in water. The cuticular membrane is not affected by 


this treatment, but the cells proper are reduced to a mass of hair-like 
bodies, shown in Fig. 217, c. 

2. The Column Cells (s) are 16-25 /" l° n g> 2 5~4° f- broad, and have 
somewhat thickened walls. 

3. The Parenchyma Cells -are also thick-walled. 

Endosperm (Fig. 218). This resembles the horny endosperm of the 
carob bean, consisting of cells with enormously swollen walls and brown 
protein contents. Cross sections are elliptical, bisected by the narrow, 
band-like sections of the cotyledons. 

Embryo. The thin cotyledons have two rows of palisade cells on 
the inner surface. They contain proteins and fat. 


This seed is one of the few belonging to the legume family that con- 
tains no starch. The cuticular membrane is alike characteristic both 
in section and surface view. It is thickest on the elliptical spots. The 
small breadth of the palisade cells, their length, and the horny character 
of the endosperm, further aid in identification. If time permits, the 
effect of soaking the material for a day or two in water should be noted. 

See General Bibliography, pp. 671-674: Hanausek, T. F. (10) ; Moeller (29) ; Vogl 


Moeller: Ueber Cassia-Samen. Bot. Ztg. 1880, 38, 737. 


The coffee astragalus {Astragalus baelicus L.) is found wild in Spain 
and Portugal, and is cultivated in other parts of Europe for its seeds, 
which, after roasting, are said to have a true coffee flavor. "Swedish 
Continental Coffee," a popular substitute for coffee, is a preparation of 
this seed. 

The seeds resemble fenugreek in color, shape, and size. They are 
brown, more or less rhombohedral with flattened ends, and are upward 
of 5 mm. long and about two-thirds as broad. The position of the radicle 
is distinctly marked on the surface. 


In anatomical structure also, the seeds of astragalus and fenugreek 
are very similar, the chief difference being in the size and structure of the 
palisade cells. 



Spermoderm (Fig. 219) 
125-150 n high, and 12-20 ,u 

1. The Palisade Cells (p) are colorless, 

broad. They are somewhat geniculate 

Although there is no distinct line of 


Fig. 219. Astragalus (A. baeticus). Surface 
view of p palisade cells and t subepidermal 
cells. X 160. (Moeller.) 

like the palisade cells of the lupine, 
demarcation, the cavity in the inner 
portion is broader and more irregu- 
lar than in the outer. 

2. Column Cells (t). These are 
hour-glass-shaped, 16-40 ,u high, 
and 35-75 f- broad. Distinct ribs 
are conspicuous both in cross sec- 
tion and surface view. 

3. Parenchyma. This layer is 
much compressed and presents no 
interesting features. 

Endosperm. 1. An Aleurone 
Layer of more or less rectangular cells 25-50 // broad forms the outer 

2. Mucilage Cells much like those of fenugreek constitute the horny 
inner portion of the endosperm. Viewed in water, only the faint outline 
of the cells is visible. 

Embryo. Proteid matter and fat form the reserve material. Starch 
is not present. The cells of the cotyledons are thronghout thin-walled 
and somewhat elongated, those in the inner layers being pronounced 

palisade cells. 


All the tissues are practically the same as in fenugreek, except the 
palisade cells, which are fully twice as high and are neither swollen nor 
pointed at the outer extremities. These cells are geniculate and nearly 
colorless. In surface view the ribbed column cells (Fig. 219, i) remind 
one of sunbursts, but this appearance is common to fenugreek, alfalfa, 
and some other leguminons seeds. Starch is absent. 

See General Bibliography, pp. 671-674: Hanausek, T. F. (10); Harz (18); Moeller 



The forage plant known as alfalfa or lucerne (Medica sativa (L.) 
Mill., Medicago sativa L.) is a native of Asia, where it has been cultivated 
since long before the Christian era. It is now extensively grown in both 



hemispheres, especially in the arid and semiarid regions of the United 
States. Ground alfalfa is a valuable cattle food. When wheat follows 
alfalfa in rotation the grain is liable to contain alfalfa seed as an impurity. 
Although the plant is described as glabrous, hairs are evident under 
a lens on the leaves and flowers. The leaves (Fig. 220, I) are alternate 
with three obovate to lanceolate leaflets finely dentate at the apex. The 
violet flowers (II) occur in racemes. At maturity the brown pods (IV) 
are coiled and contain greenish-brown seeds (III) up to 3 mm. in length. 
Numerous cultivated varieties differ from the type in the color of the 

Fig. 220. Alfalfa (Medica sal iva). I, leaf, 
Xi; II, flower, X3; HI, seed, X3; 
IV, fruit, X3. (K. B. Winton.) 

Fig. 220a. Alfalfa. Elements of stem in 
surface view, ep epidermis; /' bast 
fibers; f wood fibers; sp spiral vessel; 
to pitted vessel. X160. (K.B.Win- 

flower (blue, yellow, green, and white) and in the number of pod coils, 
seeds and leaflets. 


Stem. The elements (Fig. 220a) are not characteristic. 
Leaf. The tissues (Fig. 2206) are not only striking, but of great 
importance in diagnosis. 

1. Upper Epidermis. The cell walls are strongly sinuous. Numerous 
stomata are scattered over the surface and occasional hairs, similar to those 
on the lower epidermis, o.ccur at the base of the leaf. 

2. Mesophyl. The ground tissue is characterless parenchyma. Rows 
of crystal cells (Fig. 2206, cr) accompany the bundles. 

3. Lower Epidermis (Fig. 220b). This differs from the upper epider- 
mis principally in the greater number of hairs and their occurrence over 
the entire surface. The hairs are of two types: (1) unicellular, warty, 
thick-walled, sinuous (t 1 ) and (2) capitate, smooth, thin-walled (f) . Similar 
hairs also occur on the calyx. 



Pericarp (Fig. 220c). The hair scars of the epicarp (x) and the 
crystals cells (cr) are of interest. 

Fig. 2206. Alfalfa. Lower epidermis of 
leaf with t 1 unicellular hair, t 1 capi- 
tate hair, and sto stoma;, cr crystal 
cells accompanying bundles. X160. 

(K. B. WlNTON.) 

FlG. 220c. Alfalfa. Elements of pod in 
surface view, aep outer epidermis 
with x hair scar; iep inner epider- 
mis; cr crystal layer; / fibers. 
X160. (K. B. Winton.) 

Fig. 22od. Alfalfa. Seed in cross sec- 
tion. 5 spermoderm consists of 
pal, palisade cells with cut cuticle 
and I light line, sub subepidermal 
layer (hour-glass cells) and p par- 
enchyma; E endosperm; C cot- 
yledon with ep epidermis and 
al aleurone cells. X 160. (K. 
B. Winton.) 

Fig. 220c. Alfalfa. Elements of seed in surface 
view, pal 1 outer ends of palisade cells, pal 2 
inner ends of palisade cells, sub subepider- 
mal layer (hour-glass cells) and p 1 , p 2 pa- 
renchyma of spermoderm; ep epidermis 
and p 3 parenchyma of endosperm. X160. 
(K. B. Winton.) 

Spermoderm (Fig. 22od, 5; Fig. 2200). 1. The Palisade Cells (pal) 
are upward of 45 /j. high and 8-10 n broad, with blunt-pointed outer 



ends and thin cuticle. A narrow light line (/) is situated about 7 ji from 
the outer surface. 

2. The Column Cells (sub) although usually only 6 p. high, are broad 
(up to 45 n) . Distinct ribs are present. 

3. Parenchyma (p). The outer layers are of simple parenchyma, the 
inner of the spongy type. 

The Endosperm and Embryo contain aleurone grains but no starch. 

Fig. 221. Red Clover {Trifolium pratense). Fig. 221a. Alsike Clover (Trifo- 

Lower epidermis of leaf with t 1 unicellular Hum hybridum). Lower epider- 

hair arising I from swelling of epidermis, t 2 mis of leaf with I 1 unicellular 

capitate hair, and sto stoma. X160. hair, I 1 capitate hair, and sto sto- 

(K. B. Winton.) ma. X160. (K. B. Winton.) 


The characters of chief value in the identification of ground alfalfa 

are the form of the lower epidermal cells of the leaf, the diameter of the 

unicellular hairs, and the prominence of the warts on these hairs. The 

distinction of alfalfa (Fig. 2206) from red clover (Fig. 221) and Alsike 

clover (Fig. 221a) are brought out in the following table: 


Red Clover. 

Alsike Clover. 

Lower epidermis of 

Wavy walls 

Deeply sinuous walls 
with projections at 
angles and about 

Straight walls 

Unicellular hairs of 

Average diameter 15 
H, warts prominent 

Average diameter 30 
ju, warts prominent; 
arising from epider- 
mal swelling 

Average diameter 13 
ix, warts indistinct, , 

Palisade cells of seed 

Outer end blunt- 

Outer end flattened 

Outer end blunt- 




See General Bibliography, pp. 671-674: Harz (18). 
Winton, K. B.: Comparative Histology of Alfalfa and Clovers. Bot. Gaz., IO i 4 
57, 53. ' y *> 


Formerly the peanut {Arachis hypogaea L.) was thought to be a native 
of the Old World.but more recent investigations indicate that it is a Brazil- 
ian plant which was introduced into other regions in early colonial times. 

At the present time, peanuts are grown in Africa, Southern Europe, 
India, China, Japan, and the Islands of the Pacific, largely for the pro- 
duction of oil and oil cake, the latter serving as food for man and cattle, 
and in the United States for consumption as roasted peanuts and in peanut 
confectionery. Peanut hay, consisting of the stalks, leaves, and immature 
pods is utilized as a cattle food. About 4,000,000 bushels of peanuts 
are annually consumed in the United States, the larger part being roasted 
and sold on the street. 1 

The African variety, grown not only in Africa, but -also in India and 
other parts of the eastern hemisphere, as well as in North Carolina, yields 
a small pod with seeds rich in oil. A variety with larger pods (often 4-5 cm. 
long), but less oily seeds, is extensively grown in Virginia, yielding the 
nuts commonly roasted by venders. Tennessee produces two varieties, 
the white and the red. A small podded variety is grown in Spain partly 
for the production of oil, and partly for the cake which, mixed with choco- 
late and spices, is a common food for the lower classes. The Spanish 
peanut is also cultivated to a limited extent in America. 

Peanuts of the varieties named usually contain two seeds, less often 
one, rarely three. Costa Rica produces a variety with long pods containing 
four to five seeds. A variety grown in Argentine Republic has pods of a 
deep orange color. 

The peanut belongs to a small group of legumes which ripen their 
fruit below ground. Shortly after blooming the flower stalks bend down- 
ward until the young fruit is completely buried in the soil. If for any 
reason this does not occur the fruit fails to ripen. 

The dry pod, or pericarp, is brittle and easily broken with the fingers. 
Ten or more longitudinal ridges with anastomosing branches form more 
or less distinct reticulations on the outer surface (Fig. 222). Beneath 

1 Handy: U. S. Dept. Agr., Farmers' Bui. No. 25. 



the surface is a spongy tissue, further inward v. thin but hard woody coat 
(Fig. 222a,/), and still further inward, forming the lining of the pod, a 
papery tissue (p) with a silky luster. In the early stages of ripening the 
seeds completely fill the pod, and as a result of this crowding the adjacent 
surfaces are flattened in a diagonal plane. This flattened surface is at 
the hilum end of the upper seed, at the chalaza end of the lower seed. When 
ripe the seeds only partly fill the cavity. The united spermoderm and 
perisperm form a thin skin, red or brown on the outer, colorless or yellow 

Fig. 222. Peanut {Arachis hy- 
pogaea). Fruit, natural size. 

Fig. 2220. Peanut. Cross section of fruit, m meso- 
carp, / fiber layer and p parenchyma, of the pericarp; 
g nbro-vascular bundle; 5 spermoderm; C coty- 
ledon. X4. (Winton.) 

on the inner surface, on which are veins formed by the raphe and the 
five branches radiating from it at the chalaza. 

The elongated cotyledons (Fig. 222a, C) are longitudinally grooved 
on the inner surface. 


The Pericarp (Figs. 223 and 224), or shell, while morphologically 
corresponding with the pod of other legumes, exhibits some remarkable 
peculiarities traceable partly at least to the conditions encountered while 
ripening in the soil. Not only is it deprived of all chlorophyl and con- 
sequently of the photosynthetic power of the leaf, but, on the other hand, 
is provided with root hairs, and presumably possesses to some degree 
the absorptive function of a true root. In other words, the pericarp, 
although morphologically a leaf, acts physiologically as a root. 

1. The Epicarp Cells (ep) have such thin walls that they are seen 
with difficulty in surface view. In cross section, especially after stain- 
ing with safranin, the presence of typical root hairs, arising from the 
center of many of the epidermal cells, is evident. These hairs are not 

PEANUT. 271 

usually present on the peanuts sold by venders, due probably to 
their removal by cleaning or by friction of one against the other in the 

2. Hypoderm {hy). The cells of one or more layers beneath the epi- 
'dermis have thin non-porous walls, but further inward the walls are 

Fig. 223. Peanut. Pericarp in cross section, ep epicarp with k hair; hy hypoderm; 
mes mesocarp; qj transversely elongated fibers; Ij longitudinally elongated fibers; 
p parenchyma; 6 bast fibers, ph phloem and xy xylem, of a fibro-vascular bundle. X 80. 

thick and conspicuously porous. Owing to these pores as well as their 
quadrilateral shape the cells are readily identified in powdered shells. 

3. The Mesocarp (mes), or more properly the outer parenchyma layer, 
consists of thin-walled cells which become obliterated to a large extent 
on ripening. Over the bundles this layer is thin or lacking. 

4. Fiber Layer (Fig. 223, qf, I}; Fig. 224, /, z, g, h, k, t). A thin but 
hard coat of fibers extended in different tangential directions gives rigidity 
to the pericarp. Many of these fibers bear rows of saw-teeth (z), be- 
tween which lie the crossing fibers of an adjacent layer. At the end they 
are often branched, giving rise to halberd-shaped (h) and other curious 
forms. Many other remarkable cells varying greatly in size, form and 
wall thickness occur in this layer. 

The ridges forming the reticulations of the nut are but channeled 
outgrowths of this layer, formed by remarkable T- (/) and L-shaped 
fibers. Often in partially macerated specimens one finds a series of 
these angled fibers, part of e.ach belonging to the fiber-layer proper, the 
remainder to a ridge. 


In the channels of these outgrowths run the nbro-vascular bundles 
with well-marked bast fibers (b), phloem (ph), and xylem (xy). 

5. Inner Parenchyma (p). Cross sections of partly ripe seeds show 
a thick inner layer of pith-like cells, with triangular intercellular spaces 
at the corners. At full maturity, especially after drying the seeds, the 
compressed cells of this layer form the papery lining of the shell. 

FlG. 224. Peanut. Isolated elements of the pericarp, a and b cells of the hypoderm; 
/, s, k, k, t, d and g cells of the fiber layer. X 160. (Winton.) 

The Spermoderm (Fig. 225, S; Fig. 226) and perisperm form a thin 
dry skin which may be readily separated and sectioned either dry in paraf- 
fine, or wet between pieces of pith. As recommended by T. F. Hanau- 
sek, sections should be treated either with hydrochloric acid and alkali, 
or with Javelle water, in order to make the inner epidermis of the sper- 
moderm evident. 

1. The Outer Epidermis (aep) corresponds with the palisade layer 
of other legumes, although the two appear at first sight to have nothing 
in common. The cells are 15-25 /i high and 25-50 ft broad. Cross 



sections show that the inner walls are thin, but that the radial walls in- 
crease in thickness from within outward, and as a consequence the cavities 
are more or less triangular in shape. 


Fig. 225. Peanut. Seed in cross section. 5 spermoderm consists of aep outer epidermis, 
p l parenchyma, p 2 and p 3 spongy parenchyma, and iep inner epidermis; g fibro-vascular 
bundle; N perisperm; C cotyledon consists of ep epidermis with sto stoma and the 
porous parenchyma cells containing st starch grains and al aleurone grains. X 1 60. 

FlG. 226. Peanut. Elements of the seed in surface view, aep outer epidermis of spermo- 
derm; p 1 parenchyma; p 2 and p s spongy parenchyma; g bundle; iep inner epidermis 
of spermoderm; N perisperm;. ep epidermis of cotyledon with sto stoma. X160. 

Radially elongated pores pierce the thickened portion of the walls, 
forming ribs. Examined in surface view the sharply polygonal cells 


with thickened and porous radial walls present a characteristic appear- 

When it is considered that the palisade cells of nearly all legumes are 
polygonal in surface view and have ribbed radial walls, increasing in 
thickness from within outward, it is evident that these cells differ from 
the type merely in that they are broader, higher, and have a broader 

2. Subepidermal Layer (p 1 ). Column cells such as characterize other 
legumes are not present, the layer being of thin-walled parenchyma cells 
without intercellular spaces. 

3. Parenchyma. The character of the cells varies from ordinary 
parenchyma (p 1 ) in the outer layers to spongy parenchyma with moderate- 
sized intercellular spaces in the middle layers (p 2 ) and then to a very 
striking spongy parenchyma, with narrow branching cells and rela- 
tively large intercellular spaces in the inner layers (p 3 ). These latter 
aid in identification. Strongly developed vascular elements occur in 
the raphe bundles and its branches. 

4. Inner Epidermis (iep). Treatment of sections with Javelle water 
brings into evidence the inner epidermis. In surface preparations 
treated in the same manner, and stained with safranin, the cells are 
quadrilateral, usually elongated, with often marked evidence of division 
and subdivision of the mother cells. 

Perisperm (Figs. 225 and 226, N). A single layer of moderately 
thick-walled cells with somewhat wavy contour forms the inner coat of 
the skin. The contents, according to T. F. Hanausek, are granules 
consisting sometimes of corroded crystals. 

The Embryo (C) comprises two large cotyledons and a relatively 
small radicle. 

1. The Epidermal Cells (ep) of the cotyledons are characterized by 
their elongated form and thick outer walls. Small aleurone grains are 
present in all the cells, and starch grains of small size, according to 
Hanausek, only in the guard cells of the stomata (st). 

2. Mesophyl. Cells of large size containing aleurone grains (al), 
starch grains (st), and fat make up the larger part of the cotyledons. 
Their double walls, pierced by large pores, range up to 6 p. in thickness, 
being separated at the angles to form small intercellular spaces. The 
starch grains (up to 15 /1) are globular and have a central hilum. The 
aleurone grains vary greatly in shape and size, some of them being about 
the size of the largest starch grains, most of them, however, only half 


or a third as large. Several globoids are present in the largest 


Peanut shells (pericarp) are a normal constituent of peanut cake 
made from unhulled peanuts and of cattle food made from damaged or 
immature fruits. They are identified by the pitted, more or less quadri- 
lateral hypoderm cells (Fig. 224, a, b) and the various elements of the 
fiber layer, particularly the L- and T-shaped (t), toothed (z) and halberd- 
shaped (h) forms. The root hairs of the epidermis are difficult to find 
and the compressed parenchyma cells are not characteristic. 

Products containing the seed include peanut cake, peanut confectionery, 
peanut butter (a paste prepared from the seed after removal of the pericarp 
and spermoderm), and the mixtures of chocolate and peanut cake prepared 
in Spain and possibly in other countries. The products contain not 
only the starch (Fig. 225, st), fat and proteids of the seed, but also in 
greater or less amount the tissues of the spermoderm (Fig. 226), of 
which the porous, sharply polygonal cells of the outer epidermis (aep), 
and the spongy parenchyma cells, often with narrow arms (p 3 ), are most 
useful in diagnosis. Fragments of the spermoderm, brown or red on the 
outer, yellow on the inner surface, can often be picked out under the 
single microscope. 

See General Bibliography, pp. 671-674: Benecke (2); Bohmer (10); Hanausek, 
T. F. (48); Harz (18); Moeller (29); Vogl (45). 
Bilteryst: Recherche de l'arachide et de son tourteau dans le chocolat. Jour, pharm. 

chim. 1897, 6, 29. 
Kobus: Rraftfutter und seiner Verfalschung. Landw. Jahrb. 1884, 13, 813. 
Uhlitzsch: Ruckstande der Erdnussolfabrikation. Landw. Vers.-Stat. 1892, 41, 385. 
Winton: The Anatomy of the Peanut with Special Reference to its Microscopic Identifi- 
cation in Food Products. Conn. Agr. Exp. Sta. Rep. 1904, 191. 


South America produces the larger part of the Tonka or Tonquin 
beans of commerce, the chief ports of shipment being Angostura in Vene- 
zuela, Surinam in Guiana, and Para in Brazil. 

The true Tonka bean is the seed of Coumarouna odorata Aubl. (Dip- 
teryx odorata Willd.), but less important commercial sorts are the products 


of other species of the same genus (C. oppositijolia (Aubl.) Taub., etc.). 
They are used in perfumery, flavoring extracts, and medicines. 

As seen in the market, the black seeds vary from 25-50 mm. in length 
and from 10-20 mm. in breadth, measured across the flattened sides at the 
broadest part. One edge of the seed is sharp, the other blunt, the hilum 
being situated on the blunt edge near one end. The surface is wrinkled 
and often covered with white crystals of coumarin, the flavoring principle 
of this seed as well as of the leaves of sweet clover (Melilotus officinalis), 
sweet vernal grass (Anthoxanthum odoratum), and the sweet woodruff 
(Asperula odorata). Two large cotyledons with a small radicle at the 
end make up the embryo. 


T. F. Hanausek has called attention to the histological structure of 
this seed, which shows some remarkable variations from the usual legu- 
minous type. 

Spermoderm. This, together with the perisperm and the nearly 
obliterated endosperm, separates from the embryo as a thin, brittle shell. 

1. The Palisade Cells are much thinner- walled than in ordinary 
legumes, the cavity being broader than the double walls even in the outer 
portion where the walls are thickest. A nearly black substance fills the 
cavity. Seen in cross section, these cells are rectangular; in surface view, 
polygonal. The outer half of each cell is thickened by ribs arranged 
parallel to the axis and separated from each other by narrow slits or pores. 
Focusing on this outer portion of the cell, the thickened walls in surface 
view appear beaded. The cells are 50-65 fi high and 16-25 J" broad. 
After maceration in alkali their characteristics are manifest. 

2. The Column Cells have thickened walls and are not in close contact. 
Although hour-glass-shaped, the cells are often curiously distorted. They 
are 15-24 ji high, 30-50 ji broad. 

3. Spongy Parenchyma with moderately thick walls and well marked 
intercellular spaces forms the third layer. In the inner layers the cells 
are much compressed. 

4. An Inner Epidermis or pigment layer consists of transversely 
elongated cells with dark contents. 

Perisperm. A layer of aleurone cells is classed by Hanausek as a 
nucellar remnant or perisperm. 

Endosperm. Within the aleurone layer is a hyaline membrane with 
jndistinct cellular structure, the remains of the endosperm. 

Embryo. The isodiametric cells of the cotyledons contain round 


starch grains (4-9 /x) and yellow, irregularly elongated aleurone grains up 

to 35 n long, embedded in a ground substance of fat and proteid material. 

As the aleurone grains are insoluble in water, both these and the starch 

grains are clearly differentiated by extracting sections with ether and 

mounting in potassium iodide iodine. Hanausek found that if the section 

was treated with alcohol before mounting in iodine solution, only a faint 

blue color appeared in the starch grains, a phenomenon which he attributed 

to the formation of a protective coat over the grains preventing the entrance 

of the iodine. 


Although synthetic coumarin has, to a large degree, replaced Tonka 
beans, the latter are still used in considerable amount in perfumery, 
snuff, and flavoring extracts. As vanilla extract is often mixed with 
extract of the Tonka bean, it is quite possible that ground vanilla beans 
are adulterated with ground Tonka beans. 

Coumarin may be isolated and quantitatively determined by chemical 
means; but the microscope must be depended on to detect ground 
Tonka beans. 

The palisade cells with dark contents, characteristic alike in section 
and surface view, the irregularly shaped column cells and the grains of 
aleurone and starch contained in the cotyledons, render identification a 
simple matter. 


See General Bibliography, pp. 671-674: Hanausek, T. F. (48); Planchon et Collin 
(34); Vogl (44). 


The nutritive elements of the carob bean (Ceratonia Siliqua L.) reside 
chiefly in the fleshy pods, which contain a high percentage of sugar. 
It is believed that the husks eaten by the prodigal son were the pods of 
this bean, then as now a common swine food; also that the locusts and 
wild honey on which John the Baptist subsisted while in the wilderness 
were respectively the seeds and pods of this same bean, hence the name 
St. John's bread. 

Throughout the countries bordering on the Mediterranean the carob 
tree is cultivated and the pods are used as food for the poorer classes 
and cattle, also for the preparation of drugs, sirups, alcoholic liquors, 
etc. In Germany they are eaten by children as confectionery. 

The several-seeded fruit is 10-20 cm. long, 2-3 cm. broad, 5-10 mm. 



thick, and has several cells with a coriaceous lining (endocarp), each 
containing a flattened, obovate seed 8-10 mm. long of a dark wine color. 
On either side of the furrowed sutures the pods are swollen, and within 
each of the four swollen portions occurs a row of cavities, which are 
readily seen in longitudinal section. 


Pericarp (Fig. 227). Although this fruit is similar in structure to 
other legumes, several of the tissues have individual characteristics which 
allow of their ready identification. 

b x 

FIG. 227. Carob Bean (Ceratonia Siliqua). Elements of pericarp in surface view, ep 
epicarp with s stoma; rp brown hypoderm; b bast fibers; mc mesocarp with z wrinkled 
bodies. X160. (Moeller.) 

i. Epidermis (ep). Of the several layers of cells with dark-brown 
contents which together form the leathery outer portion of the pod, the 
outermost consists of polygonal cells (12-30 /1) and stomata, with cuticu- 
larized outer walls. 

2. The Hypodermal Layer (rp), often 120 /i thick, is made up of 
6-10 layers of tabular parenchyma cells, which, in surface view, are 
rounded. They are filled with brown contents like that in the epicarp. 

3. Fibro-vascular Bundles. The bast fibers (b) form a nearly unin- 
terrupted layer. They are accompanied by crystal- fibers (k), each con- 
taining a single crystal, and stone cells (st). Further inward are the 
phloem and xylem, the latter containing only a few vascular elements. 


4. Mesocarp (mc). The fruit-flesh or mesocarp is a thick tissue 
of large, thin -walled, radially elongated parenchyma cells, containing 
sugar and large, curiously wrinkled, reddish-brown lumps (2). These 
lumps are insoluble in water, alcohol, acetic acid, and dilute sulphuric 
acid. Chlorzinc iodine colors them yellow, the cell-walls blue. A 
highly characteristic reaction is the colors produced by caustic soda 
or potash. If the alkali is cold and dilute, the color changes first to 
green, then to blue-gray. Heating produces a violet color. If, however, 
the alkali is strong and heat is cautiously applied, a magnificent deep 
blue is obtained at once. This color is insoluble in alcohol and ether, 
but slowly changes on exposure to the air (more quickly with hydro- 
chloric acid) to red-brown. 

5. Inner Fiber Layer. The cavities containing the seeds have a 
chartaceous lining or "endocarp" consisting of bast fibers, crystal 
fibers, and stone cells, much like those occurring in the fibro-vascular 
bundles of the outer pericarp, also of an inner epidermis. The fibers 
in this layer are arranged transversely, in other words, at right angles 
to those of the outer pericarp. 

6. The Inner Epidermis or Endocarp proper consists of a single 
layer of small, isodiametric cells (15-25 n) with swollen and conspicu- 
ously beaded walls. 

The Spermoderm is closely united with the endosperm. 

1. The Palisade Cells examined in water are 170-250/1 high, of which 
35-50 n is a swollen outer layer with no evident lumens. 

2. Column Cells. The walls of the hour-glass-shaped column cells 
swell greatly, so that the cavities are hardly discernable. Intercellular 
spaces are, however, distinctly evident. The layer is 20-35 f- thick. 

3. Parenchyma. The walls throughout are greatly swollen. In 
the outer and middle layers, the cells are large ; in the inner layers small, 
and in addition dark colored. 

The Endosperm (Fig. 228) is green- white, of a dense horny structure. 
In the middle of the broad side of the seeds it is 2 mm. thick, but dimin- 
ishes toward the edges, where it is almost entirely absent. The partitions 
between the cells are enormously thickened, owing to a deposition of 
a carbohydrate material in the intercellular spaces. On heating with 
water this intercellular substance dissolves, while the swollen inner 
membrane or true cell-wall remains intact. Protein and fat are the 
only visible cell-contents. 

Embryo. In cross section the embryo appears as a narrow, yellow 



band less than i mm. thick, extending along the entire longer axis of the 

ellipse dividing the endosperm into two semielliptical halves. 

Three inner layers of palisade cells and several outer layers of iso- 

diametric cells form the mesophyl. The contents are aleurone grains 

and fat. 


Ground carob beans are used as a cattle food and a coffee substitute. 
The brown, wrinkled bodies (Fig. 227, 2) of the mesocarp are identified 

Fig. 228. Carob Bean. Endosperm with thickened cell walls. (Moellee.) 

by the blue color produced by heating with 5-10 per cent alkali. The 
bast fibers (b) and other elements of the bundles, also the cells of the 
epicarp (ep) and hypoderm (rp) with brown contents, are readily found, 
but are not characteristic. Of the seed elements, the long palisade cells 
with swollen outer walls, and especially the endosperm cells (Fig. 228), 
are most remarkable. The latter are best identified in sections cut from 
the white, horny fragments. 

See General Bibliography, pp. 671-674: Bell (1); Harz (i8);Moeller (29); Vogl (45). 
Makliere: Sur la graine et spdcialement sur l'endosperme du Ceralonia Siliqua. 
La Cellule, 1897, 13, 5. 



PALM FRUITS (Palmce). 

The fruits of the palms are either fleshy (e.g. date) or dry (e. g. cocoa- 
nut). The endocarp of certain of these nuts is a thick layer of stone 
cells. The reserve material of the seed, consisting largely of fat and 
proteid (cocoanut, palm nut) or of cellulose in the form of thickened 
cell-walls (date, ivory nut), is usually stored in the endosperm. 


The cocoanut palm (Cocos nucifera L.) yields food for man and 
cattle, oil, fiber, and other useful products, also adulterants. 

The flowers are arranged in spikes branching from a central axis 
and inclosed with a tough spathe usually a meter or more in length. A 
single female flower is borne near the base of each lateral axis, and numer- 
ous male flowers are distributed on all sides of the axis between the female 
flower and the apex. After the male flowers drop, the naked lateral 
axis persists, forming a prominent appendage of the fruit (Fig. 229, A). 
Only one ovule of the three-celled ovary comes to maturity, but the tri- 
carpellary nature of the fruit is indicated by its triangular shape as well 
as by the longitudinal ridges and the three eyes or germinating holes of 
the nut. When ripe the fruit is inverted pear-shape, 25 cm. or more in 

The epicarp (Fig. 229, Epi) is a smooth tough coat, of a brownish 
or grayish color. 

The mesocarp (Mes), consists of a thin, but hard outer coat, and 
a soft portion usually 3-4 cm. thick on the sides and much thicker on 
the base, with numerous longitudinally arranged fibers. 

Oftentimes the inner layers of the mesocarp become impregnated 
with a brown fluid, which on drying gives the thin tissue a mottled brown 

The endocarp, or shell (Fig. 229, End; Fig. 230), consists of a hard. 



dark-brown coat, 2-6 mm. thick, with numerous fibers adhering to the 
surface. Three nearly equidistant ridges (often indistinct) pass from 
base to apex, where they unite to form a blunt point. At the basal end, 
between the ridges, are the three depressions or eyes (K), the tissues of 
which are much softer and thinner than those of the rest of the shell. 



Fig. 229. Cocoanut (Cocos nucifera). S lower part of axis forming stem; A upper end 
of axis with scars of male flowers; Epi epicarp; Mes mesocarp with fibers; End endocarp 
or hard shell; T portion of spermoderm adhering to endosperm; Alb endosperm sur- 
rounding cavity of the nut; K germinating eye. XJ. (Winton.) 

Through the softest of these eyes the embryo, embedded in the endosperm 
directly behind it, escapes in sprouting. 

The Spermoderm of the anatropous seed (T) is a thin coat of a light- 
brown color, closely united with the endocarp without and the endo- 
sperm within. Embedded in the outer portion and extending from trie 
principal eye nearly to the apex is the raphe, consisting of a thin. band 
of vascular tissues about i cm. broad, which sends off branches in all 
directions, forming a network about the seed. The endosperm with 
the inner portion of the spermoderm may be separated from the outer 
spermoderm and endocarp by introducing a knife-blade between the layers. 
By this operation the veins are split, part of the vascular tissue adhering 
to the convex surface of the inner spermoderm and the remainder to 



the concave surface of the outer spermoderm, so that both surfaces are 
covered with reticulations. 

The endosperm or meat {Alb.) is a white, fleshy 
layer, 1-2 cm. thick, in which, near the base, 
is embedded the small embryo. While imma- 
ture, the nut is filled with a milky liquid and has no 
solid endosperm, but as the ripening proceeds the 
endosperm is gradually formed and at the same 
time the milky liquid diminishes in quantity or 
entirely disappears. 

The epicarp and mesocarp are cut away from 
nuts designed for export, although invariably a 
small amount of the mesocarp with its fibers re- 
mains attached to the shell. The dried meat 
(copra) is exported in large amount to Europe, 
where the oil is expressed. 

Fig. 230. Cocoanut. In- 
ner surface of shell with 
adhering outer spermo- 
derm. At the left the 
raphe, from which pro- 
ceed veins forming a net- 
work over the surface. 
Xi. (Winton.) 


Pericarp. 1. The Epicarp consists of a single layer of rectangular 
cells with dark contents. 

Fig. 23t. Cocoanut. Cross section of a large flattened (mesocarp) fiber, zle stegmata; 
/ sheath of bast fibers; ph two phloem groups; x xylem; p parenchyma of ground 
tissue; a rudimentary bundle belonging to small branch. X90. (Winton.) 

2. Mesocarp. The outer portion consists of a ground tissue of thick- 
walled, porous cells, through which pass longitudinally arranged strands 



of bast elements. Further inward the ground tissue is thin-walled 
parenchyma and the strands are well developed fibro-vascular bundles. 
Wherever the brown liquid previously referred to has penetrated the 

Fig. 232. Cocoanut. Longitudinal section of a large (mesocarp) fiber, sle stegmataj. 
Si silicious body; / bast fibers; t tracheids with small pits; /' tracheids witfi large .pits; 
sp spiral vessel ; r reticulated vessel; sc scalariform vessel ; s sieve tube; c and c' cambi- 
form cells. X300. (Winton.) 

inner layers of the mesocarp, groups of the parenchyma cells here and 
there, being impregnated with this material, are of a brown color and 
appear thicker-walled than the others (Fig. 234, br). This brown sub- 
stance is quickly changed to a reddish color by alkali, but is not 
affected by alcohol, ether, or the specific reagents for proteids, fats and 

resins. No immediate effect is produced by 
ferric chloride solution, but on long standing 
the color is changed to olive-green. 

Coir fibers (Figs. 231 and 232) are built 
up of a thick sheath of bast fibers with rows of 
stegmata on the surface, and within the sheath 
two groups of phloem and one of xylem. 
As seen in surface view the stegmata (ste) are circular or elliptical, 
thick-walled cells (8-20 p.) extending in longitudinal rows over the surface 
of the fibers. Inclosed in each cell and filling it almost completely is 
a silicious body (Fig. 233), 6-12 fi, with wart-like protuberances on the 

The phloem elements are sieve tubes and cambiform cells; the xylem 
elements, spiral, reticulated and scalariform vessels, also tracheids. 

Fig. 233. Cocoanut. Silicious 
bodies from the stegmata of 
a fiber. X1500. (Winton.) 





glaj||§§|&s >End 


qst — ^ 

Fig. 234. Cocoanut. Cross section of shell. End endocarp or hard shell; Mes adhering 
mesocarp; T adhering outer spermoderm; w colorless parenchyma of mesocarp; br 
same as w but impregnated with a brown substance; g vascular bundles in the endo- 
carp, with phloem and xylem partially obliterated; 1st longitudinally elongated and 
isodiametric stone cells; qst transversely elongated stone cells. X60. (WrNTON.) 



3. Endocarp (Figs. 234 and 235). This coat, known commonly as the 
shell, is a dense aggregation of stone cells, among which run longitudi- 
nally, partially destroyed bundles. 

The stone cells have thick, deep yellow walls, branching pores, 
and dark-brown contents. They are either isodiametric or strongly 


Fig. 235. Cocoanut. Longitudinal-radial section of shell (endocarp) through the stone 
cells and edge of bundle, qst transversely elongated and isodiametric stone cells; 1st 
longitudinally elongated stone cells; / thick-walled porous cells; g pitted vessel; sp 
spiral vessel. X300. (Winton.) 

elongated. The latter (often 20 fi long) are usually spindle- or wedge- 
shaped-, although hammer-shaped, hooked and various other curious 
forms abound. 

They are arranged in groups, commonly with the longer diameters in 
tangential transverse directions and are best seen in cross sections of 
the shell (qst), but in some groups, particularly those adjoining the 
bundles, they pass longitudinally about the shell (1st). 

Groups of thinner-walled cells with dark-brown contents are occa- 
sionally met with. 



The brown contents of all the endocarp cells react the same as the 
brown impregnating material of the mesocarp. 

Vascular bundles (Fig. 234, g; Fig. 235) are studied with difficulty in 
the mature shell. By the rupture of the phloem and part of the xylem 
during growth, passages are formed, which, in shells transversely cut or 
broken, are evident to the naked eye as minute holes. The structure 


Fig. 236. Cocoanut. Tangential section of outer spermoderm showing ground tissue 
of thick-walled porous cells. Most of these are empty, but a few contain brown contents 
in the form of k globules, or v films with circular openings, st colorless stone cells; 
sp spiral trachea. X300. (Winton.) 

of the bundles is still further obscured by the presence of fungus threads 
and spores. 

In structure the bundles differ from those of the mesocarp fibers, 
the bast fibers being replaced by forms (/) intermediate between these 
and tracheids. The vascular elements are chiefly spiral vessels (sp), 
and pitted vessels (g), the latter being especially noticeable. 

Spermoderm. i. Outer Layers. This coat consists of a ground 
tissue of large, variously shaped cells, crossing one another in all direc- 
tions (Fig. 236), between which ramify the veins. 

2. Inner Layers. Firmly attached to the endosperm are from ten 
to twenty layers of small isodiametric or slightly elongated cells. The 


double walls are about 3 p thick and free from pores. These cells con- 
tain a material varying in color from light yellow to dark brown, which 
either fills them completely or occurs in globules, films, etc., as in some 

of the cells of the outer spermoderm. In 
the layer adjoining the endosperm the cells 
are smaller and have darker brown con- 
tents than the cells in the other layers. 

Endosperm (Fig. 237). In the outer 
layers, the prismatic cells are nearly iso- 
diametric (about 50 p in diameter), but 
further inward they are radially elongated, 
often reaching a length of 300 p. Double 
cell-walls are about 3 p thick. According 
to T. F. Hanausek, the radial walls are 
non-porous; the tangential walls, however, 
show large, but indistinct pores, which are 
evident after heating with water or treat- 
ment with alkali. The cell-contents are 
bundles of needle-shaped fat crystals, and 
aleurone grains, each grain usually con- 
taining a large crystalloid, sometimes 25 p 
in diameter. Ether and alcohol readily 
dissolve the fat crystals and strong alkali saponifies them. The aleurone 
grains give the usual color reactions with iodine, Millon's reagent, 
and dyes. 


Shredded Cocoanut is the desiccated flesh of the cocoanut reduced 
to a coarse powder and usually prepared with glycerine and sugar. It 
is sold in packages for use in making pastries and confectionery. 

The microscopic elements are the thin-walled cells (Fig. 237) of the 
endosperm, containing large aleurone grains and fat, also occasional 
fragments of the spermoderm. 

Cocoanut Cake, the residue from the manufacture of cocoanut oil, 
is in Europe a well-known cattle food and adulterant of spices, but is 
almost unknown in the United States. The cells of the endosperm are 
distinguished from those of the palm nut by their thinner walls; the 
contents of large aleurone grains and fat are, however, much the same 
in the two species. Of no little value in diagnosis are the tissues of the 

Fig. 237. Cocoanut. Cross section 
of endosperm in glycerine, al 
aleurone grain; kr crystalloid; jk 
fat crystals; ei oil plasma. (T. 
F. Hanausek.) 



spermoderm, especially the porous, moderately thick-walled elements 
of the outer layers. 

Cocoanut Shells. It is stated on credible authority that in a certain 
American city several hundred tons of shells, obtained as a by-product 
in the preparation of shredded cocoanut were annually reduced to a powder 
in mills of peculiar construction and sold to spice grinders. This powder, 
without further treatment, is mixed with ground allspice, which it closely 
resembles in appearance. By cautious roasting the color of ground 
cloves and nutmegs is matched, and by roasting at a higher temperature 
a charcoal is obtained which, mixed with starchy matter, is a clever 
imitation of black pepper. 

Powdered cocoanut shells appear to be a distinctively American 
adulterant, while cocoanut cake, which in Europe is commonly em- 
ployed both as a cattle food and as an adulterant of human foods, is 
almost unknown in America. 

All the tissue elements of the mesocarp, the endocarp and the outer 
spermoderm are present in cocoanut shell powder (Fig. 238), but the 
stone cells (st) of the endocarp make up the bulk of the material. These 
stone cells are characterized by their brown-yellow walls, their dark- 
brown contents becoming red-brown on treatment with alkali, and the 
predominance of peculiar elongated forms. They differ in one or more 
of these characteristics from the stone cells of pepper, allspice, clove 
stems, walnut shells, almond shells, Brazil-nut shells, hazelnut shells, 
peach stones and olive stones. 

The outer spermoderm or lining of the shell also forms a consider- 
able part of the powder, the most striking elements being the thick- walled 
porous cells (/>) and the vascular elements. 

Colorless cells of the mesocarp ground tissue (w) are not distinguish- 
able from the parenchyma of many other plants, but when impregnated 
with the brown substance which has been described they are striking 
objects (br). Alkali changes the color of these brown cells to a reddish 
brown, but ferric chloride does not produce any immediate effect, thus 
distinguishing them from the brown cells of allspice seed, the color of 
which alkali removes and ferric chloride changes at once to a 

Spiral, reticulated, and pitted vessels (sp, t, and g), from the meso- 
carp, endocarp, and spermoderm bundles, are also frequently met with 
in the powder, the pitted vessels being quite unlike any vascular ele- 
ments of the spices. 

2 go 


The stegmata (ste) of the mesocarp fibers with their silicious con- 
tents are characteristic, but they are difficult to find owing to the great 

Fig. 238. Cocoanut shell. Elements in powder form, si dark-yellow stone cells with 
brown contents; t reticulated vessel; sp spiral vessel; g pitted vessel; w colorless, and 
br brown parenchyma of mesocarp; / bast fibers with ste stegmata. X160. (Winton.) 

preponderance of other tissues. Bast fibers (/) are more liable to be 
encountered than stegmata, but they furnish less conclusive evidence. 

Spices adulterated with charred cocoanut shells show under the 
microscope black, opaque fragments which are not bleached by aqua 
regia, or nitric acid and potassium chlorate. Except in cases where 
some of the stone cells or other elements have escaped charring, this 
material cannot be distinguished from other forms of charcoal. 


See General Bibliography, pp. 671-674: Benecke (2); Bohmer, (6, 10, 23); Col- 
lin et Perrot (9); Hanausek, T. F. (16, 17, 48); Harz (18); Moeller (29); Planchon 
et Collin (34); Vogl (45). 

Moeller: Die Rohstoffe des Tischler- und Drechslergewerbes. Cassel. 1884. 
Winton : The Anatomy of the Fruit of Cocos nucijera. Amer. Jour. Sci.- 1901, 
12, 265. Conn. Agr. Exp. Sta. Rep. 1901, 208. Amer. Jour. Pharm. 1901, 
73, 523- 


Closely related to the cocoanut, although differing greatly from it in 
macroscopic appearance, is the drupaceous fruit of the oil-palm (Elaeis 
GvAneensis L.). 



The palm fruit is about the size of a date and has a deep-red, oily 
fruit flesh or mesocarp, and a hard endocarp. Within the thin, brown 
spermoderm is a blue-gray endosperm containing a minute embryo, and 
within the endosperm is a small cleft corresponding to the large cavity 
of the cocoanut. 

Palm oil is expressed from the seed, which has previously been freed 
from the mesocarp and the greater part of the endocarp. 


After shelling, a few stone cells of the endocarp often remain attached 
to the. spermoderm. These, in surface view, are polygonal with distinct 

The Spermoderm (Fig. 239, s) is composed of several layers of thin- 
walled, tangentially elongated cells, those in one layer often crossing 
those of the adjoining layer. The &bsm^*? 


outer cells contain a brown sub- 
stance, the inner, a material which, 
according to T. F. Hanausek, be- 
comes lemon-yellow with alkali. 

The Endosperm (Fig. 239, E) 
of the palm -nut is distinguished 
from that of the cocoanut by the 
thicker walls (double 5 n) and more 
distinct pores, the walls, in section, 
having a knotty appearance. As 
a rule, the cells are radially elon- 
gated. Masses of fat crystals and 
aleurone grains are the most con- 
spicuous cell-contents. T. F. 
Hanausek states that crystals of 
fatty acids grouped in bundles are 
also present. Globular aleurone 
grains (a), each containing a large crystalloid, may be seen in water 
or glycerine mounts, but are best studied after successive treatment 
with tincture of iodine and very dilute hydrochloric acid. This latter 
procedure, recommended by Hanausek, colors the grains yellow, the 
brilliant crystalloid being clearly seen through the transparent proteid 
envelope. In the inner layers, the aleurone grains are often 25 /j. in 
diameter, in the outer layers, much smaller. 

Fig. 239. Palm-nut (Elaeis Guineensis). 
Outer portion of seed in cross section. 
s spermoderm; E endosperm containing 
a aleurone grains. X160. (Moeller.) 

292 NUTS. 


Palm Cake and the meal prepared from it is imported from Africa 
into Europe for cattle feeding. It is also much used as an adulterant 
of pepper. 

This product is distinguished from cocoanut cake by the distinctly 
porous, knotty-thickened walls of the endosperm (Fig. 239, E). Tissues 
of the spermoderm (s) and endocarp are also of service in identi- 

The aleurone grains (a), fat masses, and bundles of raphides, which 
make up the bulk of the material, are rendered distinct by treatment 
with iodine tincture followed by dilute hydrochloric acid. 


See General Bibliography, pp. 671-674: Benecke (2); Bohmer (6, 10, 23); Collin 
(8); Hanausek, T. F. (10, 16, 17, 48); Harz (18); Moeller (29); Schimper (37); 
Villiers et Collin (42); Vogl (45). 

Emmerling: Ueber Palmkernkuchen und mehl. Landw. Vers. -Stat. 1898, 50, 5. 
Haxausek, T. F. : Ueber die Frucht der Oelpalme. Ztschr. allgem. osterr. Apoth.- 

Yer. 1882, 15, 325. 
Kobits: Kraftfutter und seine Verfalschung. Landw. Jahrb. 1884, 13, 813. 
Meyer, A.: Ueber die Oelpalme. Arch. Pharm. 1884, 22, 713. 
Moeller: Ueber afrikanische Oelsamen. Dingl. polyt. Jour. 1880, 23S, 252. 


The seed of the wax-palm (Corypha cerifera L., Copemica ccrifera 
Mart.) for a long time has been used in Brazil as a coffee substitute and 
in recent years has been introduced into Europe. 

The seed, similar in size and shape to a small acom, is of a light-brown 
color with irregular, dark-brown, longitudinal striations. The inner 
surface of the spermoderm and the adhering outer surface of the endo- 
sperm are deeply wrinkled. A small embryo is embedded in the endo- 
sperm at the base of the seed near the hilum. 


The Spermoderm consists of: (1) two or more layers of small, thin- 
walled, polygonal cells ; (2) several layers of large, isodiametric or slightly 
elongated, rounded, sclerenchyma cells with moderately thick, porous 
walls, and numerous intercellular spaces; and (3) a thick tissue of paren- 
chymatous elements. 


Endosperm. As regards the structure of the endosperm, the seeds 
belong in the same class with the coffee bean, the ivory-nut, the date 
stone and other seeds with carbohydrate reserve material largely in the 
form of cellulose. The cell-walls are porous, somewhat thinner than 
those of the date endosperm. 


See General Bibliography, pp. 671-674: Villiers et Collin (42); see also Bibliog- 
raphy of Coffee: Brunotte; Konig. 


Several species of the genus Phylelephas, of which, P. macrocarpa 
R. et P. is the most important, yield the true ivory-nuts or vegetable 
ivory used in making buttons and other articles. The sawdust and 
similar refuse, after being roasted, has been mixed with coffee and pos- 
sibly other ground food products. 

The true ivory-nut, as it appears in commerce, is of about the size 
of a hen's egg, but is shaped more like a segment of an orange. It con- 
sists of a brittle shell (the inner pericarp), gray on the surface, but 
dark within, and inclosed in this a large seed with a thin, brown spermo- 
derm. The endocarp and seed are grown together during the earlier 
stages of development, but when fully ripe, the endosperm together with 
most of the spermoderm shrinks away from the endocarp and becomes 
loose in the cavity. On the surface of the loose seed may be seen the 
raphe and its numerous branches, also near the hilum, a wart-like pro- 
tuberance beneath which is a small cavity containing the germ. 


Pericarp. Three layers of the pericarp form the shell. 

1. The Outer Layer is made up of several layers of thickly porous, 
colorless cells arranged in radial rows like cork cells. 

2. Palisade Cells. These remarkable cells, brought to notice by 
Molisch, are 500 /x high and 40-90 // broad, with thickened inner and 
side walls of a dark-brown color. The side walls diminish in thickness 
toward the top, the cavity being as a consequence funnel-shaped. 
What is most remarkable of all is the presence in each cell of a silicous 
body entirely filling the cavity. These bodies may be clearly seen after 
reducing sections to an ash and dissolving out other mineral matter with 
hydrochloric acid. 

2 9 4 


3. Collapsed Cells form a thin layer beneath the palisade cells. 
Spermoderm (Fig. 240, S). 1. Sclerenchyma Fibers with dark con- 
tents, crossing one another in the different layers, form the outer coat. 
The separation of the pericarp from the seed takes place in the 
layer through which ramify the raphe and its branches, the outer portion 

of the spermoderm remaining attached 
to the inner surface of the pericarp. 

2. Inner Layers. Large, nearly 
isodiametric cells with thick walls, 
but without evident pores, complete 
the spermoderm. These are shown 
at the left in Fig. 241. 


Fig. 240. Ivory-nut {Phytelephas macro- 
carpd). Cross section of outer layers. 5 
spermoderm; E endosperm with thick- 
ened cell walls. (Moellee.) 

Fig. 241. Ivory-nut. Elements of 
spermoderm. X 1 60. (Moeller.) 

The Endosperm (Fig. 240, E) of the ivory-nut is the most striking 
of all the examples' of reserve material in the form of cellulose. The 
cell-walls are on the average about 35 fi thick and often exceed 50 p. 
Penetrating these walls are conspicuous pores, which broaden at the 
middle lamella. Most of the cells are radially elongated. 


Ivory-nut powder, a material used as an adulterant of coffee, is identi- 
fied by the enormously thickened cell-walls of the endosperm (Fig. 240), 
also by the tissues of the spermoderm (Fig. 241) and pericarp. The 
only materials with which it might be confounded are ground date stones 
and Polynesian ivory-nuts. The date stone seldom has cell-walls as 


thick as those in the ivory-nut, furthermore, the tissues of the spermoderm 
are different. 


See General Bibliography, pp. 671-674: Bohmer (23); Hanausek, T. F. (16, 17, 
48); Moeller (29); Planchon et Collin (34); Vogl (45). 
Hanausek, T. F.: Ueber einige, gegenwartig im Wiener Handel vorkommende 

Gewurzfalschungen. Ztschr. Nahr.-Unters. Hyg. 1894, 8, 95. 
Molisch: Die Kieselzellen in der Steinschale der Steinnuss. Centr.-Org. Waarenk. 

Techn. 1891, 103. 
Moeller: Die Rohstoffe des Tischler- und Drechslergewerbes. Cassel, 1884. 


Of late years, seeds of several species of Coelococcus known as Poly- 
nesian or Tahiti ivory-nuts have been substituted for true ivory-nuts, 
and their by-products, quite probably, have been utilized for adulterat- 
ing foods. 

T. F. Hanausek finds that these seeds differ from true ivory-nuts 
in having: (1) longer but narrower endosperm cells; (2) more conspicu- 
ous middle lamellae; (3) distinct diagonal markings on the cell-walls as 
seen in section; and last but most important, crystals of calcium oxalate 
as cell-contents. 


Hanausek, T. F.: Zur Anatomie der Tahitinuss. Ztschr. allgem. osterr. Apoth.- 
Ver., 1880, 13, 360. Ztschr. Nahr.-Unters. Hyg. 1893, 7, 197. 

WALNUTS (Juglandacea). 

The fruits are 2-4 celled, with a rather thick, leathery mesocarp 
and a hard, 2-4 celled endocarp or nut shell. The seed consists largely 
of a curiously furrowed embryo with reserve material in the form of 
fat and proteid matter. The endocarp is made up of a dense mass of 
colorless stone cells. Characteristic of the spermoderm are the large 


The walnut tree {Juglans regia L.), a native of Asia, is extensively 
cultivated throughout the central and southern regions of Europe, par- 
ticularly in France, Italy, Spain, and Greece, also within the past few 



years in California. As European nuts reach America by way of Eng- 
land they are known there as English walnuts. 

Inclosed by the husk, the fruit is usually 4-8 cm. long and about 
two-thirds as broad. When dry the epicarp and strongly scented 
mesocarp separate from the nut proper, consisting of the shell or endo- 
carp and the seed. The nut is light brown, ovoid, short-pointed, and 
marked on the surface by shallow furrows and depressions. Encircling 
it longitudinally is a suture, into which a knife-blade may be easily in- 
serted, thus separating the shell into two equal segments. Thin par- 
titions divide the cavity imperfectly into four cells at the base and two 
at the top. The curiously wrinkled and lobed orthotropous seed, con- 
forming in shape to the embryo, is covered with a thin, brownish-yellow 
skin or spermoderm. The embryo has two large cotyledons arranged 
at right angles to a plane passing through the suture and partially 
separated from each other by a thin partition; each cotyledon is deeply 
lobed, the lobes being separated by another partition at right angles 
to the first. The relatively small, pointed radicle is directed upward. 


Only the endocarp and seed need be studied, as the epicarp and 
mesocarp are removed before the nuts are marketed. 

Pericarp. Sect ons of the shell are cut with a strong blade or are 
obtained by grinding on an oil stone (p. 13). 

1. The Outer Endocarp (Fig. 242), the hardest part of the shell, is 

a dense aggregate of nearly isodiametric 
cells with almost colorless walls so strongly 
thickened that the lumen is scarcely evi- 

2. Middle Endocarp (m). The cells in- 
crease in size and the walls diminish in 
thickness in the middle layers, the thick- 
ness of the walls in most of the cells being 
much less than the breadth of the lumen. 
Many of the cells have irregularly concave 
faces, a peculiarity noticeable even in 
powdered shells. 

3. The Inner Endocarp (i) is a loose 
parenchyma with thin, brownish walls becoming darker on addition of 


Fig. 242. Walnut {Juglans regia). 
Tissues of shell, a stone cells 
of outer layer; m stone cells 
of middle layer; i parenchyma 
of inner layer. X 160. (Moel- 


Spermoderm. The seed may be easily sectioned without special 
preparation. The cell structure should be studied after treatment with 
Javelle water and staining; the aleurone grains, in sections mounted 
directly in turpentine or, after extraction with ether, in glycerine. 

i. Outer Epidermis. As may be seen in cross section, the thin- 
walled, prismatic cells, containing yellow or brown material, are more 
or less radially elongated, and often divided by tangential partitions. 
In surface view they are sharply polygonal. The large stomata, often 
broader than long, are very noticeable. 

2. The Middle Layers are composed of compressed yellow-brown cells 
which do not usually assume their original form on treatment with 
Javelle water. 

3. Inner Epidermis. The cells of this layer are also compressed, 
but on soaking in Javelle water swell to their original form. 

Perisperm. The hyaline membrane, forming what appears to be 
the thickened outer wall of the endosperm, is probably the remains of 
the perisperm. 

Endosperm. The outer cell layer of the seed flesh, although usu- 
ally firmly attached to the second layer, is sharply differentiated from 
the latter, the two layers being separated by a thick membrane. This 
outer layer is endosperm. Seen in surface view, the polygonal cells are 
15-40 ft in diameter and have thick walls. They resemble the aleurone 
cells of cereals. 

Embryo. The cells are of the' usual thin-walled parenchymatous 
type and contain irregular aleurone grains up to 10 [i in diameter, also 
oil globules. 


The Seeds or "meats" are largely used in foods, either whole or 
chopped. The residue from the manufacture of walnut oil is obtained 
in limited amount in Europe and is utilized as a cattle food. 

The most conspicuous elements are the polygonal outer epidermal 
cells of the spermoderm and the broad stomata. 

Ground Walnut Shells are in Europe a common adulterant of spices. 
The elements are of three forms: (1) the small but thick- walled, color- 
less stone cells (Fig. 242, a) of the outer layers; (2) the colorless stone 
cells (m) of the middle layers, characterized by their large size, broad lu- 
men, and irregular, here and there concave, outline; (3) the loosely 
united cells (i) of the inner layers, with thin, yellow or brown walls. 

298 NUTS. 


See General Bibliography, pp. 671-674: Bohmer (23); Collin et Perrot (9); Han- 
ausek, T. F. (10, 16); Mace" (26); Moeller (29); Villiers et Collin (42); Vogl (45). 
Godfrin: Etude histologiquesurles tegument se"minaux des Angiospermes. Soc. d. ScL 

d. Nancy. 1880, 109. 
Hartwich: Ueber die Fruchtschale von Juglans regia. Arch. d. Pharm., 1887, 25, 325. 
Pfister: Wallnusskuchen. Landw. Vers.-Stat. 1894, 43, 448. 
Young: A Study of Nuts with Special Reference to Microscopic Identification. 
U. S. Dept. Agr. Bur. Chem., Bull. 160. 


The black walnut tree {Juglans nigra L.), a native of America, is 
valuable chiefly for its wood. The globular nut is about the same size 
and shape as the European walnut, but has an exceedingly rough endo- 
carp with deep furrows and numerous sharp, branching ridges. 

Notwithstanding these differences, the two nuts have much the same 
microscopic structure. The aleurone grains are somewhat smaller in 
the American species, but the difference is too slight to be decisive. 

The nut is sometimes found on the market. 


This American nut, the fruit of Juglans cinerea L., differs from the 
black walnut chiefly in being elongated, and sharply pointed at both 
ends. The structure of the two is practically the same. 


One of the most valuable native nuts of the United States, is the 
pecan nut (Carya olivaejormis Nutt.), produced by wild and cultivated 
trees in the central and central southern states. 

The nut is smooth, elongated, 3-4 cm. long, taper-pointed, and very 
indistinctly six-ribbed. It is divided at the base into two cells. Although 
small, the meats have a mild, delicious flavor, and are much used in 
confectionery, while the shells are available for adulterating spices. 

In structure both the seed and shell are much like those of the 
English walnut. The aleurone grains are, however, somewhat smaller, 
seldom exceeding 6 p. in diameter. 



In addition to the pecan tree, various others of the same genus yield 
edible nuts, of which the shellbark or shagbark hickory-nut, (C alba 
Nutt.) is the most valuable, and is the only one gathered in considerable 
amount for the market. The somewhat flattened nut of this species is 
about 3 cm. long and nearly as broad, the light colored, more or less 
angular but otherwise smooth surface, being marked with six indistinct 
ribs ending abruptly in a sharp point at the apex. 

The structure of the hickory-nut is the same as that of the pecan nut. 

CUP NUTS {Cupuliferd). 

These nuts are usually borne in an involucre or cup. The pericarp 
is horny or leathery, with stone cell layers. The single seed consists 
largely of embryo, which is either starchy (acorn, chestnut) or fatty 
(beech-nut, hazelnut). The hairs of the pericarp and spermoderm are 
often of service in diagnosis, as are also the starch grains of the two 
species named. 


The European or Spanish chestnut (Castanea saliva Mill.), the Ameri- 
can variety (C saliva var. Americana Michx.), and the Japanese chest- 
nut (C. crenata Sieb. et Zucc.) are all forest trees of great value, not 
only for their timber but for their edible" nuts. In Spain, southern France, 
Italy, and other countries bordering on - the Mediterranean, chestnuts 
form a staple article of diet with the poorer classes, while in other 
European countries and in America they are regarded more as delicacies. 

Spanish and Japanese chestnuts are large, 2.5 cm. or more broad, 
whereas those of the American variety are only 1.5-2.5 cm. broad. 
Commonly 2-3, rarely 4-7, nuts are enclosed within a densely spiny 
involucre or burr which does not open until the nuts reach full maturity. 
The outer nuts in the burr are plano-convex, the inner flattened on both 
sides. At the base they are broad and rounded, at the apex pointed 
with more or less of the style attached. The dark brown, leathery peri- 
carp is smooth and glossy, except on the broad scar at the base, where 
it is dull and lusterless, and near the point, where it is hairy. On the 

300 NUTS. 

inner surface it is covered with a dense mat of silky hairs. The thin, 
brown spermoderm separating readily from the seed, is sparingly pubes- 
cent on the outer surface, but on the inner surface is smooth, although 
marked by irregular ribs corresponding to the furrows on the surface 
of the cotyledons. The flesh of the large cotyledons is starchy, and 
when dry is readily reduced to a powder. It has a sweet taste. 


Fresh or dried nuts of either the Spanish or American chestnut may 
be used for laboratory work. 

Pericarp. Transverse sections, also tangential sections at different 
depths may be cut with a strong razor and examined both with and with- 
out treatment with alkali. 

i. Epicarp. The cells are polygonal or quadrilateral, either iso- 
diametric or longitudinally elongated, in the latter case often arranged 
end to end in irregular rows. Their contents are of a deep-brown color. 
Hairs are present at maturity only about the apex, although hair scars 
are found on other parts. They are pointed or rather blunt, 2-3 mm. 
long, and vary greatly in breadth and wall-thickness. The breadth 
of the lumen in the larger hairs is greater than the thickness of the walls, 
but in the case of the smaller hairs the reverse is often true. 

2. Sclerenchyma. The cells of the outer layers, as appears from 
cross sections, are radially elongated, often 50 // high, and have thick 
walls. In tangential section they are either isodiametric or longitudi- 
nally elongated, the walls being deeply sinuous and much folded, remind- 
ing us of the intestine cells of capsicum. Their shorter diameter is usu- 
ally over 25 fi. In the middle layers the cells are smaller than in the 
outer, have relatively thicker walls, and are polygonal in outline; while 
in the inner layers large cells with broad lumen predominate. The 
structure of the tissues beneath the scar varies somewhat from those 
described and many of the cells contain large oxalate crystals. 

3. Mesocarp. Longitudinally elongated, more or less quadrilateral 
cells with very thick, beaded walls form the middle layers of the peri- 
carp. The cell-contents are colored brown and the cell-walls yellow- 
brown. Intercellular spaces frequently occur at the corners of the cells 
and between the side walls. Fibro- vascular bundles with strongly de- 
veloped bast tissues run through the mesocarp. 

4. Endocarp. This layer is itself inconspicuous owing to the dense 
mat of hairs forming the woolly lining of the pericarp. The hairs vary 


up to several millimeters in length and up to 35 (i in breadth. They are 
pointed, often crooked, and have broad lumen and very thin walls. 

Spermoderm. This coat may be separated from the seed as a papery 
brown membrane. 

1. The Outer Epidermis consists of polygonal cells up to 50 ft in 
diameter, interspersed with hairs similar to those on the endocarp. 

2. Middle Layer. The loose tissue of brown cells traversed by fibro- 
vascular bundles is of little interest. 

3. An Inner Epidermis of polygonal cells without hairs completes 
the spermoderm. 

Embryo. The parenchymatous tissue of the cotyledons contains 
numerous starch grains (Fig. 243) up to 30 ft in diameter. Among 
the large grains are ovoid, pear-shaped, fusiform, rounded triangular, 
polygonal, and various irregular forms, often with wart-like excres- 
cences. The hilum is commonly eccentric, indistinct, and may or may 
not have radiating clefts. With suitable illumination, rings are clearly 


Chestnut Meal is a food product of considerable importance in south- 
ern Europe, where it is made into puddings, cakes, and even into bread. 
Starch (Fig. 243) is the predominating element. The large grains are 

Fig. 243. Chestnut Starch (Castanea vesca). X600. (Moellee.) 

less than 30 ft in diameter, and are of the various irregular forms 
already noted, with inconspicuous, eccentric hilum. Hairs from the peri- 

302 NUTS. 

carp or spermoderm, like those of the acorn, beech-nut, and hazelnut, 
are remarkable for their thin walls and broad lumen. 

Chestnut Shells are characterized by the thin-walled hairs, the 
sclerenchyma cells with thick, sinuous walls, and the thick-walled, beaded 

See General Bibliography, pp. 671-674: Hanausek, T. F. (16); Harz (18); VogI 
(45); Wiesner (48). 
Godfein: Etude histologiquesurles tegument seminauxdesAngiospermes. Soc. d. Sci. 

d. Nancy. 1880, 109. 
Hanausek, T. F. : Zur mikroskopischen Charakteristik des Kastanienmehles. Beilage 
der Ztschr. f. Landw. Gewerbe. Dobruska, 1883, No. 1, 3. 


Several European species of oak, notably Quercus Cerris L., Q. pedun- 
culate Ehrh., Q. sessiliflora Salisb., and Q. pubescens Willd., yield edible 
acorns, the kernels of which are used chiefly for making a substitute 
for coffee ^known as acorn coffee. In America, acorns are produced in 
large quantities by numerous native species and are eaten on the ground 
by swine, but as yet are not gathered for the market. 

Whatever the species producing it, the acorn is characterized by its 
well-known form, the short wart at the apex, its smooth surface, and 
the circular scar at the base. The cup-shaped, scaly involucre (the 
cupule) in some species is shallow, in others deep, nearly covering the 
acorn. The pericarp is made up of a hard outer coat and soft inner 
tissues of a deep brown color, the innermost layer or endocarp being either 
smooth or densely woolly. A thin, brown spermoderm incloses the 
embryo, the latter consisting of two large fleshy cotyledons and a small 
radicle. Endosperm is lacking. 


The structure of acorns of different species is very similar, the 
chief differences being in the presence or absence of hairs on the en- 
docarp and the size of the starch grains. 

Cupule. 1. The Outer Epidermis consists of polygonal cells averag- 
ing 14 n in diameter interspersed with numerous pointed hairs varying up 
to 700 n in length. In the inner half of each hair the lumen is broad, 

1 Free use has been made of the descriptions of Mitlacher, who has studied the cupule, 
pericarp, and spermoderm of Quercus sessiliflora. 



but toward the apex it is reduced to a narrow line. At the base the hairs 
are somewhat constricted owing to pressure of adjoining cells. 

2. Middle Layers. In a ground tissue of thin- or moderately thick- 
walled chlorophyl parenchyma are distributed numerous stone cells 
occurring either singly or in small groups. These cells vary in form 
and are usually between 100 and 200 ft in diameter. The solitary cells 
have thinner walls than those in groups and often contain crystal clusters 
of calcium oxalate. The bicollateral bundles are accompanied on the 
outer side by sclerenchyma fibers and rows of crystal chambers. 

3. The Inner Epidermis is much like the outer in structure. 

Pericarp. 1. The Epicarp (Fig. 244, epi; Fig. 245) on the lower part 
of the fruit is made up of cubical cells regularly arranged in rows, form- 


Fig. 244. Acorn (Quercus sp.). Tissues of shell in cross section, epi epicarp; st crystal 
cells and stone cells; mes mesocarp. (Moeller.) 

ing a highly characteristic tissue. These cells contain colorless drops 
in a brown ground substance. On the upper end in many species are 
numerous hairs (Fig. 247, 1) similar to those of the cupule. 

2. Crystal Layer. An interrupted hypodermal layer of thin- walled, 
isodiametric cells, each containing a large rhombohedral crystal of cal- 
cium oxalate, is clearly seen both in transverse and tangential sections. 



3. Stone Cells (Fig. 244, st). Radially elongated, spindle-shaped 
cells up to 56 n long and 10-20 n broad, with thick, sparingly porous, 
and indistinctly stratified walls and narrow lumen make up the outer 
three or four layers. In the inner layers these pass by degrees into 
isodiametric cells with walls narrower than the lumen. 

At the apex of the fruit the dense stone cell tissue is replaced by a 
brown parenchyma in which are numerous small stone cells with brown 
walls and contents and broad lumen. Similar cells form a second hard 
layer further inward. The stone cells of the basal portion of the peri- 
carp have characteristic branching pores. 

4. Outer Mesocarp (Figs. 244, mes). The loosely united cells of 
this tissue in the ripe fruit are t much compressed. The only noticeable 

Fig. 246. 

Acorn. Brown parenchyma of pericarp. 

X160. (MOELLER.) 

Fig. 245. Acorn. Epicarp 
in surface view. X160. 

cell-contents are occasional crystal clusters of calcium oxalate. Through 
this tissue pass the fibro-vascular bundles 

5. Inner Mesocarp. A spongy parenchyma (Fig. 246) of cells arranged 
end to end in longitudinal rows forms a characteristic tissue. In cross 
section these cells are round, in tangential section elongated with 
numerous connecting arms. The contents are yellow-brown. 

6. The Endocarp is characterized by the numerous exceedingly thin- 
walled hairs (Fig. 247, 2), also by the presence of small crystals of vari- 
ous forms. 

The Spermoderm is thicker over the furrows of the cotyledons than 
in other parts. 

1. Outer Epidermis. The thin- walled, tabular cells are polygonal 
in surface view, both the walls and the contents being of a deep brown 
color. Hairs from this layer are shown in Fig. 247, 3. 

2. The Middle Layers, through which ramify the bundles, consist 
of a loose brown parenchyma containing crystals of various forms. 

3. The Inner Epidermis is much the same as the outer. 



Embryo (Fig. 248). The polygonal epidermal and subepidermal 
cells of the cotyledons contain distinct nuclei, each inclosing a crystalloid. 
Similar nuclei occur along with starch grains in the small subepidermal 
cells. The remainder of the tissue is a parenchyma with round cells 
about 100 fi in diameter, having very small intercellular spaces at the 
angles. They are closely filled with ellipsoidal or irregular elongated 
starch grains (st) usually 15-20 p., rarely and only in some varieties, 

Fig. 247. Acorn. Hairs: i from epicarp; 2 from endocarp; 3 from spermoderm. 


50 fi long with very distinct, elongated hilum. The grains usually occur 
singly, although twins and various larger aggregates similar to those 
found in tapioca, sago, and buckwheat are not uncommon. The ellip- 
soidal forms remind us of the leguminous starches. Fibro- vascular 
bundles with small spiral vessels pass through the ground tissue. 


Acorn Co fee is a product of considerable importance. It is pre- 
pared from the shelled nut and should contain only traces of the tissues 
of the pericarp and spermoderm. The conspicuous elements are the 
ellipsoidal or irregularly elongated starch grains (Fig. 248, st) with elon- 



gated hilum, reminding us of leguminous starch. These are distorted in 
the roasted product. 

A corn Flour is mixed with chocolate and other food preparations. 

Acorn Shells are used as an adulterant of acorn coffee and possibly 
of other food products. The quadrilateral epicarp cells (Fig. 245) in reg- 
ular rows overlying the crystal cells, the spindle-shaped stone cells (Fig. 
244, si) with narrow lumen, also other forms with broad lumen, and 


Fig. 248. Acorn. Elements of cotyledon, ep epidermis; E parenchyma; st starch; 
sp spiral vessel. X300. (Moellee.) 

finally the exceedingly thin-walled hairs (Fig. 247), are the tissues of most 
importance in diagnosis. 

The Cupule is also said to serve as an adulterant. The geniculate 
hairs of the outer epidermis with constricted base, also the stone cells 
of the middle layers are the elements of diagnostic value. 


See General Bibliography, pp. 671-674: Berg (3); Hanausek, T. F. (10, 16); 
Harz(i8); Hassell (19); Mace" (26); Moeller (29); Villiers et Collin (42); Vogl (43, 45). 
Hager: Ueber Eichelkakao und Chokolade. Pharm. Ztg. 1888, 33, 511. 
Hanausek, T. F.: Mikroskopische Untersuchung eines hollandischen Eichelkakao. 

Ztschr. Nahr.-Unters. Hyg. 1887, 1, 247. 
Michaelis: Eichelkakao, Eichelchokolade. Pharm. Ztg. 1888, 33, 568. 
Mitlacher: Die Fruchthiillen der Eichel (Fructus Quercus sessilifloras) und ihre 

mikroskopische Feststellung als Beimengung zum Eichelkaffee. Ztschr. allg. 

osterr. Apoth.-Ver. 1901, 39, 1. 
Tardieu: Eichelmehl enthaltendes Weizenmehl. Ann. chim. analyt. 1898, 3, 307. 
Tschirch: Untersuchung der Eichel-Kakaosorten des Handels. Pharm. Ztg. 1886, 

32, 190. 



The European beech (Fagus sylvatica L.) and the American species 
(F. ferruginea Ait.) yield nuts which, like the walnuts, contain no starch 
but a high percentage of oil. Beech-nuts are collected on a commercial 
scale in the forests of Europe for oil production, the cake being utilized 
as a cattle food. Owing to the presence of cholin the cake is poisonous 
for horses, but is not injurious to bovine cattle or swine. 

The American beech grows in abundance in the eastern half of the 
United States. In Virginia and other states the nuts are eaten by swine 
as they drop from the tree, the ham and bacon of these animals being 
especially prized for their fine flavor; but in most sections they fall a 
prey to squirrels and other wild animals. 

The brown nuts are triangular, winged near the apex, and clothed 
with a coat of minute hairs hardly visible except under a lens. Two 
of these nuts are borne in a prickly involucre or cupule, which splits 
into four valves. The ovary is trilocular, each with two ovules, but the 
partition wall disappears during development and only one ovule reaches 
maturity, completely filling the fruit cavity. Remains of the partitions 
are evident on the inner surface of the pericarp as ridges running through 
the middle of the three sides. Silky hairs occur in some numbers along 
these ridges. The brown spermoderm is of thin papery texture and 
is united with a still thinner endosperm. Running through one of the 
angles is the raphe, which sends off several distinct branches running 
through the other two angles as well as in the tissues between. At first 
sight the embryo appears homogeneous, but on closer inspection is 
seen to consist of much folded cotyledons connected with a minute radicle. 


Either the European or American beech-nut may be used for study, 
as both are essentially the same in structure. 

Pericarp. Transverse sections are cut from the middle of the sides 
and at the angles, also tangential sections at different depths. 

1. The Epicarp Cells are polygonal with moderately thin, faintly 
beaded walls and contain either a brown homogeneous material or well- 
formed crystals. The hairs of this layer are short, pointed, and usually 
thick-walled. Hanausek notes that thin- walled, twisted hairs, also 
multicellular forms are occasionally found. 

3° 8 NUTS. 

2. Sclerenchyma. Stone cells in 5-10 layers form a dense hypo- 
dermal tissue about the nut. These are rounded, nearly isodiametric, 
and have thick and distinctly porous walls and brown or yellow-brown 

3. The Mesocarp consists of several layers of tangentially elongated 
parenchyma cells with thick, porous walls, impregnated with brown 
coloring matter. As appears in cross section, large V-shaped bundles 
of bast fibers pass through the brown parenchyma in the angles, 
strengthening the tissues. In the inner portion of the layer broad fibro- 
vascular bundles with strongly developed bast fibers form an almost 
continuous layer. Accompanying the bundles are crystal fibers. 

4. The Endocarp is of parenchyma cells interspersed about the par- 
tition wall with long, thin- walled hairs. 

Spermoderm. 1. Epidermis. The cells are polygonal, often over 50/* 
in diameter and have deep brown walls, which Pfister notes are sub- 

2. Brown Parenchyma Cells similar to those of the epidermis but 
smaller, form one or two subepidermal layers. 

3. A Spongy Parenchyma of colorless compressed cells, and 

4. An Inner Epidermis of thin-walled elements completes the spermo- 

Endosperm. Adhering to the inner surface of the spermoderm is 
a single layer of thick-walled, polygonal aleurone cells forming the endo- 

Embryo. The epidermis on the inner sides of the cotyledons has 
larger cells than on the outer. Both layers have thickened outer walls. 
The ground tissue in the outer portion of the cotyledon consists of iso- 
diametric cells passing into one or more layers of palisade cells in the 
inner portion. Procambium bundles occur in the middle layers. The 
cell-contents are aleurone grains up to 15 ft, fat, and calcium oxalate 
rosettes. Hanausek notes that a single rosette is present in each cell 
as may be seen after treatment with alkali. 


Undecorticated Beech-nut Cake can be easily identified by the tissues 
of the pericarp and spermoderm, provided fragments sufficiently large 
for cutting sections are present; otherwise the task is not an easy one 
as the tissues, although both striking and varied, are not especially char- 
acteristic in surface view. The epicarp with short, usually thick-walled 


hairs, the isodiametric stone cells, the bundles accompanied by bast 
fibers and crystal fibers, and the long, thin-walled hairs of the endocarp, 
are the most striking elements. 

Decorticated Beech-nut Cake is still more difficult of diagnosis. The 
tissues of the cotyledons are much the same as those of numerous other 
oil seeds, and the brown cells of the spermoderm in surface view are not 
distinctive. Tissues of the pericarp, particularly the hairs, are however 
present even in decorticated cake, and on these the microscopist must 
largely depend in forming his conclusion. 

See General Bibliography, pp. 671-674: Bohmer (23); Collin et Perrot (9); Ha- 
nausek, T. F. (17, 48); Harz (18). 
Pfister: Buchnusskuchen. Landw. Vers.-Stat. 1894, 43, 445. 


The hazelnut is of no little importance in Europe both as a table 
nut and for the production of hazel oil ("nut oil "), which is used on the 
table and in the arts. 

The numerous European and Asiatic varieties have probably been 
derived from three species: the common hazel (Corylus Avellana L.), 
Lambert's hazel or filbert (C. tubulosa L.), and the Turkish hazel 
(C. colurna L.), of which the Spanish or cobnut (C. pontica Koch) is 
perhaps but a variety. Three native American species (C. Americana 
Walt., C. rostrata Ait., and C. Californica Rose.) also yield nuts of 
excellent quality, but are not as yet cultivated. 

The nuts of all the species named are inclosed in a leafy involucre 
consisting of two more or less foliaceous members, which in C. tubulosa, 
C. rostrata, and C. Californica is prolonged into a narrow tube, but in 
the other species is short and open. The nuts of the various species and 
varieties differ both in size and in the ratio of breadth to length. They 
have a broad circular scar at the base, and a short blunt point. On 
the lower portion they are smooth, on the upper covered with a gray 
bloom consisting of numerous minute hairs visible only under a lens. 
The pericarp or shell consists of a hard outer coat 1-2 mm. thick and 
a brown spongy inner coat. Through the outer part of the hard coat, 
corresponding to longitudinal streaks visible from without, pass fibro- 
vascular bundles which in cross section appear as dark-brown spots in 
the light-colored, woody ground tissue. One, rarely two, hemitropous„ 



nuts are suspended from, the top of the cavity. Each seed consists largely 
of fleshy cotyledons, the radicle, the brown spermoderm and the colorless 
endosperm forming but a small portion of its bulk. The short raphe, 
about half the length of the nut, and the nerves radiating from the chalaza 
are distinctly seen through the spermoderm. 


Commercial hazelnuts of any variety may be studied. After noting 
the macroscopic characters, particularly the bloom on the outer sur- 
face, the brown fibro-vascular bundles of the pericarp and the spermo- 
derm with its raphe and nerves, transverse sections 
and surface mounts should be prepared. 

Pericarp, i. The Epicarp is best obtained by 
boiling the shell in dilute alkali and scraping with 
a scalpel. Fragments from the upper part of the 
shell consist of thin-walled, isodiametric, polygonal 
cells interspersed with numerous hairs. In cross 
section (Fig. 249) it may be seen that the hairs 
are deeply planted between the thin-walled cells. 
Characteristic of these hairs are their thick walls, 
the lumen being scarcely evident except in the 
basal portion, and the bright yellow color produced 
by alkali. On the lower half of the shell the 
layer consists of isodiametric, somewhat elongated 
cells and hair scars, the hairs themselves usually 
being lacking. 

2. Outer Stone Cells (Fig. 249). The hard 
portion of the shell is in three layers, each of 
colorless stone cells distinctly different from those 
in the others. The stone cells in the outer layer 
Fig. 249. Hazelnut (Cory- are characterized by their rounded isodiametric 
hSrsTand stonTraiilln form, distinct outline, and especially, as noted by 
(Mal- Malfatti, by their loose arrangement. They gradu- 
ally increase in size from 15 p in the outer layers 
to 50 fi in the inner. Being in loose contact, they separate readily on 
grinding. Through this layer pass the large bundles, often 500 fi in 
diameter, which in the ripe nut are usually disorganized. 

3. Middle Stone Cells. In this layer the stone cells are radially 
elongated and closely arranged. 

cross section. 


4. The Inner Stone Cells are larger than those in the two outer 
layers and have thicker walls and broader cavities. They are either 
isodiametric or tangentially elongated and have brown contents. Ha- 

• nausek has rightly observed that their contour is ill-defined on direct 
examination, but becomes more distinct on addition of alkali. This 
latter reagent imparts to the walls of the stone cells in all three layers 
a bright yellow color. 

5. Brown Parenchyma, at maturity more or less disorganized, forms 
the inner layers. 

Spermoderm. 1. The Outer Epidermis of polygonal cells with dis- 
tinct outline and colorless contents is clearly seen in surface mounts or 
cross section. 

2. Hypoderm. Two or three cell layers similar to the epidermis 
form the next coat. 

3. Brown Cells make up the compressed inner tissues. 
Endosperm. One to three layers of typical aleurone cells are 

closely united with the embryo. 

Embryo. Hanausek first observed that the cells of the embryo 
contain spherical aleurone grains 16-30 // in diameter, with rounded glo- 
boids embedded in a yellowish granular ground substance. 

These are clearly seen on mounting in alcohol sections previously 
extracted with ether. In water the ground substance gradually dis- 
integrates, liberating the globoids. Hanausek states that minute granules 
of starch are also liberated, but these are not commonly evident. 


Hazelnut Meal prepared from the kernel without removal of the 
fat has been used in conjunction with wheat and rye flour for bread- 
making. 1 This product consists chiefly of embryo tissues with the char- 
acteristic yellow, globular aleurone grains from which the rounded 
globoids gradually separate on the addition of water. Fragments of the 
spermoderm are also present. 

Hazelnut Cake. Meager details are available as to this product, 
although considerable quantities must be obtained in the manufacture 
of hazelnut oil. Its microscopic characters are the same as of the unex- 
tracted kernel. 

Ground Hazelnut Shells have been detected by Malfatti, Micko, T. F. 

1 Plagge and Lebbin : Veroffentlichungen auf dem Gebiete des Militar-Sanitatswesens 
1897, 12, 193. 

3i2 NUTS. 

Hanausek, Mansfeld, and others as an adulterant of cinnamon. The 
elements (Fig. 249) are the epicarp cells interspersed with hairs or hair 
scars, the colorless stone cells of the woody portion of the pericarp, 
and the brown obliterated tissues of the inner pericarp. The hairs are • 
characterized by their thick walls, narrow lumen and the yellow color 
produced on addition of alkali. Among the stone cells are isodiametric 
forms of various sizes from the outer layers, readily separating from one 
another on grinding, elongated forms from the middle layers, and large 
cells with thick walls and broad lumen from the inner layers. 


See General Bibliography, pp. 671-674: Hanausek, T. F. (16); Villiers et Collin 
(42); Vogl (4s). 
Hanausek, T. F. : Ueber den hystologischen Bau der Haselnusschalen. Ztschr. allg. 

osterr. Apoth.-Ver. 1892, 30, 61. 
Hanausek, T. F.: Ueber einige, gegenwartig im Wiener Handel vorkommende 

Gewiirzfalschungen. Ztschr. Nahr.-Unters. Hyg. 1894, 8, 95. 
Malfatti: Eine neue Verfalschung des Zimmtpulvers. Ztschr. Nahr.-Unters. Hyg. 

1891, 5, 133. 
Micko: Haselnusschalen als Verfalschungsmittel der Gewiirze. Ztschr. allg. osterr. 

Apoth.-Ver. 1892, 30, 42. 



Young has shown that the Brazil-nut, also known as the Para-nut 
from the port of shipment, and incorrectly as the castanea-nut, is the seed 
of Bertholletia nobilis Miers. and not of B. excelsa Humb. et Bpl. (order 
Myrtacece) although the latter yields a similar nut. The tree grows in 
forests on the banks of the Amazon and Rio Negro. 

The fruit is spherical, about the size of a cocoanut, which it further 
resembles in having a hard endocarp. The ovary is four-celled, each 
containing numerous ovules borne on a central placenta in two rows; 
but on ripening the partitions disappear. At maturity the seeds are 
usually three-sided, resembling the segments of a small orange. On 
the surface they are transversely roughened and of a dark gray color. 
The hard shell-like spermoderm, as seen in section, has an outer coat 
1 mm. or less thick of a light color, and an inner coat, of softer dark-brown 
tissue with a glossy inner surface. Running through the inner coat in 


the angles is a hard tissue, triangular in cross section, with broad bands 
of vascular elements on the inner side through which the tissues readily 
separate. On cutting away the inner tissues, it may be seen that the 
vascular elements forming the band in the straight edge belong to the 
raphe, the delicate lateral ramifications being directed upward or trans- 
versely, while those in the two curved edges proceed from the chalaza with 
lateral ramifications directed downward. The flesh of the nut is largely 
radicle. Young states that the minute cotyledons located about 5 mm. from 
the apex may sometimes be found under a lens after soaking in water. 

Spennoderm. Transverse sections should be cut through the shell 
at the angles and through the tissues half way between the angles. Radial 
longitudinal sections at the angles and tangential sections through the 
epidermis and the raphe are also instructive. 

1. Palisade Cells. The epidermis consists of greatly elongated, 
sclerenchyma cells arranged perpendicularly to the surface, forming a 
palisade layer 0.5-1 mm. thick. These remarkable cells have narrow 
branching cavities and thick colorless walls, except at the extreme outer 
end, where the cavity is broad. In tangential section they are poly- 
gonal, varying up to 50 fi in diameter. 

2. Outer Brown Tissue. This. is a spongy parenchyma with small 
cells containing a deep brown substance responding to the tests for tannin. 
On the sides of the seeds it passes directly into the inner brown tissue. 

3. Stone Cells. At the angles these cells form a hard tissue, broadly 
triangular in cross section, extending the entire length of the seed. The 
cells are for the most part isodiametric, reaching a maximum diameter 
of 100 fi. The transition to brown tissue in the outer layers is gradual, 
the intermediate tissues being composed of stone cells interspersed with 
parenchyma elements. The stone cells have colorless walls of medium 
thickness and brown contents, and are conspicuous both in sections and 
in the powdered shells. In the inner layers the cells are longitudinally 


4. Fibro-vascular Bundles. The thin broad bands on the inner 
surface of the stone-cell tissue forming in the straight edge the raphe, and 
in the curved edges the branches of the raphe, contain numerous small 
spiral vessels. As the inner spermoderm separates from the outer 
through this tissue, tangential sections are easily prepared. 

5. Inner Brown Tissue. The cells in the inner layers are larger than 
those of the outer layers and form a closer tissue. 

314 NUTS. 

Endosperm. After removing the shell, the meat of the nut, con- 
sisting largely of radicle, is in perfect condition for sectioning either 
with a razor or a microtome. In cross sections we note that the cells 
in the first two or three layers are sharply differentiated from those 
further inward, suggesting that they may not belong to the embryo at 
all, but are endosperm or less probably perisperm. 

Embryo. Next follows 8-15 layers of thin-walled, circular cells 
(30-60 ,«) in loose contact, forming a cortex, then a procambium of 
narrow longitudinally-elongated cells, along which Young finds rudi- 
mentary vascular bundles. A medullary tissue of round cells varying 
up to 100 n in diameter makes up the inner portion of the meat. All 
the cells of the embryo contain aleurone grains, of which the solitary 
grains, often 30 ji in diameter, each with a large crystalloid and an irregular 
globoid mass, are especially noticeable. Because of these grains which 
are among the most striking protein bodies found in the vegetable king- 
dom, the nut is often used in laboratories as a material for study. 


The Meat or Embryo is used whole or broken in confectionery. In 
sections mounted in turpentine the large aleurone grains are the notice- 
able elements. Fragments of the brown inner spermoderm are often 
attached to the outer surface. 

The Cake remaining after expressing the oil contains the elements 
already noted. 

Shells of the Brazil-nut have been ground for adulterating spices. 
This material is identified by the following characters: (1) the colorless, 
sclerenchyma palisade cells of the spermoderm which occur in groups of 
more or less rectangular form; (2) the deep-brown parenchyma; (3) 
the isodiametric stone cells with colorless walls and often with deep- 
brown contents. 

Young finds that the sapucaia or paradise nut (Lecythis usitata Miers) 
is similar to the Brazil-nut in structure, but the cortex is thicker (about 
14 cells), the endosperm consists of but one cell layer, and the inner 
spermoderm is very thin and contains crystal rosettes. 

See General Bibliography, pp. 671-674: Hanausek,.T. F. (16); Tschirch (39). 
Hofmeister: Pflanzenzelle, 1867, 178. 
Millardet: Ann. Sc. nat. iv ser. 34. 
Young: See reference, on p. 298. 



The pistachio tree (Pistacia vera L. order Anacardiacece), was culti- 
vated in Asia Minor and Egypt in the days of Joseph, and was introduced 
from these countries into Greece and Rome at an early period. Its 
culture is still limited largely to the Mediterranean region. 

The fruit is a dry drupe with an oily seed, which, freed from the peri- 
carp, is known in commerce as the pistachio-nut or green almond, and 
is extensively used in pastries and confectionery. The seed is elongated, 
10-25 mm- l° n g' w i tn a pronounced ridge on the dorsal side and a shal- 
low depression on the ventral side near the base. The lower portion is 
flattened from front to back, while the upper portion is flattened in a 
plane at right angles to the last. After soaking or boiling in water, the 
spermoderm and endosperm may be separated as a thin skin from the 
embryo. On the dorsal side, where it is also thickest, the spermoderm 
is dark purple, on the ventral side, green. Closely attached to the 
spermoderm is the colorless, silky-lustrous endosperm. The embryo 
consists of large cotyledons of a green color attached to a radicle sit- 
uated directly beneath the dorsal ridge. 


The Spermoderm, together with the endosperm, is sectioned without 
separation from the embryo. 

1. Outer Epidermis. The cells are polygonal, 30-60 ft in diameter, 
and have faintly beaded walls. 

2. The Middle Spermoderm consists of thin-walled cells and fibro-vas- 
cular bundles. On the ventral side only a few cell layers are present, 
but on the dorsal side, eight or more layers. The cells on the dorsal 
side, not only of the middle layers but also of the epidermis, contain a 
water-soluble substance of a carmine or brown color which becomes 
green with alkali, but is not altered by chloral. 

3. The Inner Epidermis on the dorsal side is also of thin-walled, 
inconspicuous elements, but on other parts is an exceedingly character- 
istic tissue of small, distinctly porous cells. As seen in surface view, 
the cells are 7-15 n in diameter, sharply polygonal, with, beaded walls. 
Cross sections show that some of the cells are divided by tangential 
partitions. This layer is here tentatively classed with the spermo- 
derm, although further investigation may show it to be perisperm. 

316 NUTS. 

Endosperm. The outer endosperm consists of a variable number of 
layers of typical aleurone cells, the inner layers of more or less obliterated 
cells forming a hyaline membrane. 

Embryo. The green color of the tissues is more apparent to the 
naked eye than under the microscope. The thin-walled cells contain 
spherical aleurone grains, most of which are small (3-5 fi), some however 
larger (8-14 /<). 


Pistachio-nuts, whether whole or chopped, are recognized (1) by the 
carmine or brown coloring matter in the spermoderm becoming green 
with alkali, and (2) by the exceedingly small but distinctly porous cells 
of the inner epidermis. 

Almonds and other nuts dyed with coal-tar colors are sometimes 
substituted for genuine pistachio-nuts. In a suspected sample, foreign 
tissues should be searched for under the microscope, and tests made 
for foreign dyes. 

See General Bibliography, pp. 671-674: Hanausek, T. F. (16); Planchon et 
Collin (34); Vogl (43). See also reference to Young on p. 298. .__ 


The seed kernels or " nuts " of several species of pine, notably the 
stone pine of Italy (Pinus Pinea L. order Abietinea), and the Cembra or 
Swiss pine (P- Cembra L.), including the Siberian variety (var. Siberica), 
are highly prized for their delicate resinous flavor. 

As found on the market, the kernels, consisting of the endosperm 
and embryo entirely free of spermoderm, are narrow, elongated, 1-1.5 cm. 
long, smooth, and of an ivory-white color. After boiling with water, 
the elongated embryo embedded in the axis of the endosperm, may be 
easily separated. It consists of twelve needle-shaped cotyledons 5-7 mm. 
long and a radicle of about the same length. 


' In microscopic structure both the endosperm and the embryo en- 
tirely lack characteristic elements. The thin-walled, for the most part 
isodiametric cells contain fat and rounded aleurone grains usually 3-5 «, 
less often 10-12 ji, in diameter. 

See reference to Young on p. 298 



Fruit, in the common acceptance of the term, includes such succulent 
fruits as are suited for table use. Dry fruits (cereals, buckwheats, 
pepper, anise, cocoanut, etc.), some known as seeds, others as nuts, are 
described elsewhere in this work. 

Only those fruits used for the preparation of preserves, jams, and 
other commercial products are here considered. 

Fruit Products. 

The products of pomes, drupes, berries and other succulent fruits 
include dried and candied fruits, jams, marmalades, preserves, jellies, 
sauces, and catsups. Of these some contain all the histological ele- 
ments of the fruits, including the seed tissues, others only the elements 
of the fruit flesh, and others still no cellular matter whatever, or only 

Dried Fruits are prepared from the whole fruit in the case of figs, 
dates, raisins, Xanti currants, prunes, and various berries; from the 
fruits freed from stones in the case of peaches, apricots and cherries; 
and from the pared and cored fruits, in the case of apples and pears. 
Substitution of cheaper fruits is not often practiced, as the macroscopic 
characters and taste of most of the products cannot be successfully imitated. 
The most objectionable practice is the bleaching with sulphur or "sul- 
phuring " of peaches, apples, apricots, pears, and similar fruits that show 
a tendency to turn brown on drying. 

Jams, Marmalades, and Other Preserves, like dried fruits, are pre- 
pared either from the whole fruit or the fruit flesh. After addition of 
sugar the mixture is boiled down to the proper consistency. 

The common adulterants may be classified as follows : 

i. Foreign Pulp and Gelatinous Material. Under this head may be 
included the pulp of turnips, beets, apples and figs ; the residues or pomace 
obtained in the manufacture of fruit juices and jellies; also starch-paste, 
gelatin, agar- agar, and other vegetable materials used to give " body " 
to fraudulent mixture. 


318 FRUIT. 

It is stated on creditable authority that artificial raspberry jam has 
been made in America in which grass seed took the place of fruit seeds. 
Another fraud, more difficult of detection, consists in mixing the residues 
from the manufacture of fruit juices or jellies with water, gelatinous 
materials, dyes and flavoring substances. 

2. Sweeteners other than cane-sugar include glucose sirup and also 
chemical sweeteners, such as saccharine, dulcin, etc. 

3. Dyes. Cochineal, cudbear, and various vegetable dyes, formerly 
employed in food products, are now largely replaced by dyes of coal- 
tar origin. 

4. Artificial Flavors. These are mixtures of ethers, such as ethyl 
acetate, ethyl butyrate, amyl butyrate, etc., prepared in imitation of the 
real fruit flavors. Banana and pineapple flavors are quite closely imi- 
tated, but the imitations of strawberry and raspberry flavors are sicken- 
ing mixtures, with little resemblance to the genuine. 

5. Vegetable Acids. Citric and tartaric acids are employed to give 
.artificial fruit products the requisite acidity, also to bring out the flavor 

of certain mild-flavored fruits. 

6. Chemical Preservatives. Formerly salicylic acid was the common 
preservative of fruit products, but recently, at least in America, sodium 
benzoate has largely taken its place. Saccharine may also be classed 
under this head, as it is not only a sweetener but also a preservative. 

Fruit Juices and Jellies, being strained products, are usually quite 
free from seeds, skins and pulp cells, although small fragments of tissues 
may sometimes be found on careful search. 

The adulterants are the same as are used in preserves, excepting the 
pulp of fruits and vegetables. 

Tomato Catsup, a popular sauce in America, consists of tomato pulp 
freed from seeds, mixed with spices and vinegar. It is adulterated with 
foreign pulp, notably that of the pumpkin and apple, coal-tar and other 
dyes, and chemical preservatives. See p. 412. 

Chili Sauce is made from tomatoes, peppers, spices and vinegar. It 
is not usually strained, and therefore contains seeds of both the tomatoes 
and the peppers. The adulterants are the same as of tomato catsup. 

Methods of Examination. 

Preliminary Examination. Seeds, styles, fragments of skin, and 
other tissues are picked out either from the original material, the residue 
after washing on a sieve, or the deposit that settles after dilution and 


3 X 9 

•shaking. These may often be identified by the macroscopic characters, 
but in doubtful cases should be examined under the microscope. 

Artificial flavors imitating strawberry, raspberry, and some other 
fruit flavors, are recognized by their characteristic odor and taste, which 
are quite different from those of the real fruits. Apple jelly also has a 
more or less characteristic odor, which is especially marked on heating the 

FlG. 250. Common Diatoms, a Surirella splendida; b Meridion circulare; c Nitzschia 
linearis; d Nitzschia acicularis; e Epithemia Zebra; f Tabellaria fenestrate; g Synedra 
Ulna; k Gomphonema acuminatum; i Rhoicosphenia curvaia; k Cocconema Cistula; 
I Navicula Stauroptera; m Stauroneis Phoenicentron. (Mez.) 

product. Sulphites or glucose containing sulphites, if used in consider- 
able amount, impart a disagreeable sulphurous taste. 

Chemical Examination. Methods for the detection of starch-paste, 
gelatin, glucose, dyes, preservatives, etc., are described in the works on the 
chemical analysis of foods named on page 4. 

Microscopic Examination. Direct examination is made both of the 
original material and of the seeds, styles, skin, fibro-vascular bundles, etc., 
separated by washing on a sieve or by allowing the diluted material to settle. 
Jams and similar saccharine products can be mounted without dilution, 

320 FRUIT. 

the gelatinous portion of the material forming a suitable medium in which, 
to examine the solid fragments. Owing to the heating with sugar sirup 
in the process of manufacture, as well as to the absence of starch grains, 
fat and similar interfering substances, the tissues are beautifully distinct 
and treatment with clearing reagents is usually quite unnecessary. Seeds 
may be broken up on the slide, or may be held in a hand- vice or between 
pieces of soft wood and sectioned with a razor. 

Agar-agar. Marpmann boils the jelly with 5 per cent sulphuric acid, 
adds a few crystals of potassium permanganate and allows to settle. If 
microscopic examination of the sediment discloses diatoms, agar-agar is 
probably present. 

Schimper heats the jelly on a piece of platinum foil and examines the 
residue in a drop of dilute hydrochloric acid for diatoms (Fig. 250). If, 
however, only small amounts of agar-agar are present he recommends 
Marpmann's method. 

Lagerheim calls attention to the presence of characteristic fibrous 
bodies, pointed at one end, which are always present in agar-agar and are 
readily identified. 

Lagerheim' s Test for Benzoic Acid. Place a portion of the material 
on a watch-glass and cover with a glass plate; heat to boiling, allowing the 
steam to condense on the plate. Remove the latter while still hot, allow 
the drops of liquid to evaporate and examine the residue under the micro- 
scope. If benzoic acid is present, branching crystalline deposits, resem- 
bling frost on the window-pane, are evident. As stated by Lagerheim, this 
test is so delicate as to permit the detection of the small amounts of benzoic 
acid naturally present in cranberries. 


Lagerheim: Om den mikroskopiska undersokningen af marmelad. Svensk Farm. 

Tidsk. 1901, 5. 
Lagerheim: Kralitativ bestanining af benzoesyra och salicylsyra i narings-och 

njutningsmedel genom direkt sublimering. Svensk Farm. Tidsk. 1903, 7. 
Marpmann: Beitrage zur mikroskopischen Untersuchung der Fruchtmarmeladen. 

Ztschr. angew. Mikros. 1896, 2, 97. 
Me'nier: Falsification de la gelfe de groseille du commerce decouverte par les Diatomees. 

Nantes. 1879. 
Schimper: Anleitung zur mikrosk. Unters. der veg. Nahr.-u. Genussm. Jena, 1900, 

Winton: Beitrage zur Anatomie des Beerenobsten. Ztschr. Unters. Nahr.- u. Genussm. 

1902, 5, 785. Conn. Agr. Exp. Sta. Rep. 1902, 288. 

APPLE. 321 


Most of the important tree fruits and several of the bush fruits belong 
to this family. They are grouped under three subfamilies, each with 
quite distinct characters. 

1. Pomes (Apple, Pear, Quince). The five carpels are united into a 
fleshy fruit, bearing the remains of the calyx teeth in a depression at the end. 
The morphology of pomes has long been a subject for dispute, some botan- 
ists asserting that the»outer fruit flesh is calyx tube, others that it is recepta- 
cle. At present the preponderance of evidence favors the latter theory. 

The epicarp of the quince is hairy, and the mesocarp of the pear and 
quince contains groups of stone cells. In all the pomes the cartilaginous 
endocarp of each of the five locules is made up of sclerenchyma cells. The 
seed is quite complicated in structure, consisting of a spermoderm of 5-6 
more or less characteristic layers, a thin perisperm, an endosperm of a 
few layers of aleurone cells, and a bulky embryo. 

2. Drupes (Almond, Peach, Apricot, Plum, Cherry). The most 
striking characteristic is the thick, hard endocarp or stone. Only one of 
the two ovules usually matures. The spermoderm usually consists of 
four layers, of which the epidermis is characterized by groups of thin- 
walled stone cells. The perisperm, endosperm and embryo are similar 
to those of pomes. 

3. Other Rosaceous Fruits. The raspberry and blackberry are mul- 
tiple drupes, the small individual fruits agreeing in general structure with 
the true drupes. The succulent part of the strawberry is a receptacle, on 
which are diminutive achenes. 


The apple is not only the leading table and culinary fruit of the tem- 
perate zone, but in addition ranks next to the grape for the production 
of fermented liquors. 

It is a native of eastern Europe and southwestern Asia, and has been 
cultivated since prehistoric times in the Old World, and since colonial 
times in America and Australia. The common species (Pyrus Mains 
L.) includes many varieties, differing greatly in size, shape, color of skin 
and flesh, texture, flavor, acidity, and keeping qualities. 

Notwithstanding the variations in shape, all apples have a depression 
at one end, in which are borne the withered calyx teeth, and another 

322 FRUIT. 

more pronounced at the other end, in which is inserted the woody stem. 
The skin is tough and closely adherent to the fruit flesh. In the recep- 
tacle or outer fruit flesh are embedded the five wedge-shaped carpels, 
which are also fleshy, except for the cartilaginous endocarp lining the 
cavities. At full maturity an axial cavity appears in the fruit and the 
endocarps split on their inner edges, thus opening communication between 
the cell cavities and the axial cavity. Each cell contains two brown, 
flattened obovoid seeds. 

The crab-apple (P. baccata L.) is the only other species cultivated to 
any considerable extent for fruit. In this species the fruit is small, seldom 
exceeding 40 mm. in diameter, and is useful only for cooking. The 
calyx teeth drop before the fruit reaches maturity. 


Fresh ripe apples, either hardened in alcohol or without special treat- 
ment, supply material for preparing sections. 

Receptacle and Pericarp. 1. Epidermis (Fig. 251, epi). The cuticle 
is 12-15 f 1 thick. In surface view, the thick-walled, sometimes beaded, 
mother cells, divided by much thinner walls into 2-5 more or less quadri- 
lateral daughter cells, remind us of windows, hence the name " window- 
cells." The daughter cells (15-50 u) are about twice as large as in the 
pear. In the calyx and stem depressions, the walls throughout are of 
more uniform thickness, and long, thin-walled, strap-shaped, pointed 
hairs are present. " Russet spots " consist of cork breaking through the 
epidermis. The contents of the cells are brown granular masses, occa- 
sional chlorophyl grains and, in the case of colored apples, reddish or 
violet coloring matter in solution, which becomes greenish with iron 
salts and blue-green with alkalies changing back to its original color 
with acids. 

2. Hypoderm (hy). Two or three layers of porous, collenchymatously 
thickened eel's underlie the epidermis. In cross-section they are tangent- 
ially elongated, in surface view, polygonal. Starch grains (am) 3-14 ft long, 
the larger grains with elongated hilum, the smaller often in twins, trip- 
lets, or larger aggregates, occur in the larger cells of the unripe fruit. 
In highly colored apples, coloring matter in solution is present. 

3. The Fruit Flesh consists partly of the receptacle and partly of 
the united carpels, separated by an indistinct zone evident in cross section 
to the naked eye. The bulk of the ground tissue is a mass of large thin- 
walled cells containing in the immature fruit starch grains like those 



of the hypoderm. On ripening the starch largely disappears and the 
cells (p 1 ), which separate readily by pressing with a cover-glass, appear 
like partially collapsed re f 

sacks with shriveled con- 
tents. In the layers ad- . 
joining the endocarp the 
cells are smaller, irregu- 
larly elongated, forming a 
spongy tissue (p 2 ) . They 
contain occasional crys- 
tal rosettes (cr 1 ) or, less 
often, monoclinic twins. 
Stone cells (5/ 1 ) are some- 
times present in the stem 
end, although never in 
such numbers as in the 
pear and quince. Spiral 
(sp), annular (an), retic- 
ulated (ret), and pitted 
vessels (g) form the bun- 
dles; fibers (/) and stone 
cells (st) adjoin them. 

4. Endocarp (end). The parchment-like endocarp consists of 3-7 
layers of thick-walled, sclerenchyma fibers and elongated cells, extended 

in various directions par- 
allel to the inner surface, 
forming a tissue similar 
to that found in the en- 
docarp of coffee. Rows 
of thin-walled cells, con- 
taining monoclinic twin 
crystals (cr 2 ), are distrib- 
uted among the fibers. 
Pores are distinct in the 
outer layers, indistinct 
in the inner. In the 
cleft formed by the splitting of the ripe carpels at the sutures paren- 
chyma cells and curious, jointed, branching, warty hairs (Fig. 251a) 
form dead white masses often evident to the naked eye. Some of the 

Fig. 251. Apple {Pyrus Malm). Isolated elements of the 
fruit, epi epidermis, hy hypoderm; 'fruit flesh ele- 
ments: st 1 stone cells, p 1 parenchyma containing am 
starch grains, p 2 inner parenchyma, cr 1 rosette crys- 
tals, / fiber, bundle consisting of g pitted, ret reticu- 
lated, sp spiral and an annular vessels, and st stone 
cell; end endocarp with cr 2 crystal cells. X160. 
(K. B. Winton.) 

Fig. 251a. Apple {Pyrus Malus). Hairs from suture of 
endocarp. (Malfatti.) 



hair cells, particularly the terminal ones, are sclerenchymatized, thus 
furnishing a distinction from the similar hairs of the pear and quince. 

Spennodenn. i. The Outer Epidermis (Figs. 251& and 251c, ep) is 
studied in cross sections mounted in glycerine. The radial and especially 
the outer walls are greatly thickened and show a laminated structure. 
What .appear like minute warts on the inner surface of the walls are 

due to the diagonal pits seen in surface view. 

The outer walls are mucilaginous and swell 

Fig. 2516. Apple. Seed in cross 
section. 5 spermoderm consists 
of ep epidermis, / fibers, /;( tube 
cells, tr cross cells, am starch 
cells, and iep inner epidermis; 
N perisperm with h hyaline 
layer and p 1 obliterated paren- 
chyma; E endosperm with al 1 
aleurone cells and p 2 compressed 
parenchyma; C cotyledon with 
aep outer epidermis and al 2 
aleurone cells. X160. (K. B. 


Fig. 251c. Apple. Elements of seed in surface view. 
Significance of reference letters as in Fig. 2$ib. 
X160. (K. B. Winton.) 

greatly on addition of water. Surface sec- 
tions show that the cells are longitudinally 
elongated and conspicuously marked by 
diagonally elongated pits. 

2. Hypodermal Fibers (/), longitudi- 
nally arranged, with greatly thickened brown 
walls, form 6-10 layers or about half the thickness of the spermoderm. 

3. Tube Cells (tu). Adjoining the last is a loose tissue of 2-3 layers 
of longitudinally elongated, rather thin-walled, blunt cells in interrupted 
contact, resembling the tube-cells of cereals. Diagonal markings are 
evident after bleaching and staining. In parts the tissue is a typical 
spongy parenchyma. A brown substance with the reactions of tannin 
impregnates the walls and partially fills the cells. 

4. Cross Cells (tr). The next layer resembles the preceding, but 

APPLE. 325 

the transversely elongated elements are narrower and in closer con- 

5. Starch Cells (am). A single cell layer of colorless, exceedingly 
thin-walled, transversely elongated cells contains minute starch grains. 
Were it not for these grains the layer would hardly be noticeable. 

6. Inner Epidermis (iep). These cells are also transversely elongated 
but have distinct walls. They are impregnated with a brown substance. 

Perisperm (AT). A colorless skin, consisting of perisperm and endo- 
sperm, may be found between the thick brown spermoderm and the embryo. 

1. Hyaline Layer (h). Cross sections show a thick outer mem- 
brane 3-6 [i thick and delicate radial walls. The membrane is stained 
a deep yellow with chlorzinc iodine, whereas the adjoining tissues are 
stained blue. After this treatment a delicate, cellular network is dis- 
tinguishable in surface view. 

2. Obliterated Cells (p 1 ) make up the inner perisperm. 

Endosperm (E). 1. Aleurone Cells (a/ 1 ) form the outer layers. These 
are colorless, rather thick-walled, in surface view polygonal, and contain 
aleurone grains and fat. 

2. Obliterated Cells (p 2 ) complete the endosperm. 

The Embryo (C) consists of two oval cotyledons and a relatively small 
radicle. The thin-walled cells contain aleurone grains and fat. 

Stem. Cork cells in 4-6 cell layers form the outer zone, then 4-5 
layers of small-celled collenchyma, passing by degrees into the middle 
bark. The bundles of very delicate cells are partly inclosed on the outer 
sides by the bast-fiber bundles. On the inner side they adjoin a zone 
of stone cells, interrupted only by the medullary rays. 


Preserves. Various products of the apple, such as preserves, jams, 
jellies, and sauces are sold as such and are used as adulterants of products 
of more expensive fruits, the deception being completed by the addition 
of dyes, artificial fruit ethers, and even grass seed. These products either 
contain only the fruit flesh of the apple, the tissues of which lack dis- 
tinctive character, with traces of the characteristic elements of the epi- 
dermis, the endocarp and the seed, or else, in the case of jellies, no cel- 
lular structure whatever. 

Mince Meat is a chopped mixture of apple flesh, meat, suet, raisins, 
xanti currants, sweetening and spices. Cereal flour is often added, the 
starch of which may be distinguished from apple starch. 

326 FRUIT. 

Apple Pomace, the residue from the cider-press, is used for feeding 
cattle and for other purposes. It contains all the histological elements 
of the fruit. 

The tissues of chief use in diagnosis are the epidermis, the " window " 
cells of which are larger than those of the pear; the endocarp with 
thicker- walled fibers than in other pomes; the branching, multicellular, 
warty hairs from the suture, which differ from the corresponding hairs 
of the pear and quince in that some of the cells are sclerenchymatized; 
the longitudinally elongated, diagonally pitted, thick-walled epidermal 
cells of the spermoderm, which differ markedly from the isodiametric 
cells of the pear and quince; and finally the tissues of the stem. Crystal 
rosettes are numerous in the apple, rare in the pear and quince, whereas 
the reverse is true of stone cell groups. Products of the ripe apple contain 
only faint traces of starch. 


See General Bibliography, pp. 671-674: Hassall (19). 
Boedzilowski: Ueber die Entwicklung der beerenartigen und fleischigen Friichte. 

Arb. Kiewer Naturf. Ges. 1888, 9, 65. 
Howard: Microscopical Examinations of Fruits and Fruit Products, U. S Dept. Agr. 

Bur. Chem. Bull. 66, 103. 
Malfatti: Beitrage zur Anatomie der Birn- und Apfelfrucht. Ztschr. Nahr.-Unters. 

Hyg. 1896, 10, 265. 
Strasburger: Das botanische Practician. 
Strasburger: Das kleine botanische Practicum. 


Most of the varieties of pear, including all those cultivated in Europe 
and America before the early part of the nineteenth century, are forms 
of Pyrus communis L., a native of Europe and western Asia, although 
a number of the varieties now cultivated in America, including the Le Conte 
and the Kieffer, are hybrids with the oriental pear, P. Sinensis Lindl. 

The pear differs from the apple in form, having a more or less tapering 
stem-end without a depression, also in the texture and flavor of the fruit 
flesh; but in general morphological details the fruits are identical. 

Receptacle and Pericarp. 1. The Epidermis (Fig. 252, epi), consists 
of " window cells " like those of the apple, but only half as large (10-25 J"). 
The thick cuticle V ruptured in places, particularly about the stomata, 



with the formation of cork cells beneath. In varieties with a rough 
skin, the epidermal cells proper give place almost entirely to cork tis- 
sues. In the calyx depression are thick-walled, pointed hairs 200-250 /i 

2. A Hypoderm (hy) of 3-4 layers consists of cells with knotty, 
thickened walls and collenchymatous angles. 

3. The Fruit Flesh is characterized by numerous clusters of strongly 
thickened stone cells (st 1 ), about which as a center radiate elongated 

Fig. 252. Pear (Pyras communis). Isolated elements of fruit, epi epidermis; Ay hypoderm; 
fruit flesh elements: st 1 stone cell group, p l radiating parenchyma, / fiber, bundle 
consisting of sp spiral, g pitted and ret reticulated vessels, st 2 stone cell accompanying 
bundle, and cr crystal cells of mesocarp; p 2 porous layers and ie inner layer of endo- 
carp. X160. (K. B. Winton.) 

parenchyma cells (p 1 ). The groups of stone cells are largest (often 
over 1 mm.) and occur in the greatest number in the inner layers. The 
individuals are isodiametric, often over 50 ft in diameter, or slightly 
elongated, and have colorless walls with distinctly branching pores. 
Alkali colors them yellow, safranin, red, thus making them evident in 
the ground tissue. Similar stone cells occur in the quince, but only in 
the stem end of the apple. Starch grains (4-5 [i) occur in the unripe 
fruit. The bundles are similar to those of the apple. Monoclinic twin 
crystals (cr) are numerous; rosettes are rare. 

4. Endocarp. Fibers with walls thicker than the breadth of the 
lumen, such as form the dense endocarp of the apple, are here replaced 

328 , FRUIT. 

by elongated cells with broader cavities and less strongly thickened 

Fig. 252 shows the transition forms (p 2 ) from the large parenchyma 
cells of the fruit flesh to the thin-walled elongated cells of the inner layer 
(ie). The parenchyma which forms in the suture bears multicellular, 
branching, warty hairs (Fig. 252, c) similar to those found in the apple, 
but lacking the thick-walled members. 

Spermoderm. 1. Outer Epidermis (Fig. 252a, ep; Fig. 2526). Since 
the cells are isodiametric polygonal, as seen in surface view, they may be 
distinguished at a glance from the longitudinally elongated, conspicuously 
pitted cells of the apple. Viewed in cross section they are quadratic, 
upward of 50 ji high. All of the cells have a mucilaginous secondary 
membrane and groups of cells also have a thickened tertiary membrane, 

Fig. 252a. Pear. Cross section of outer layers Fig. 2526. Pear. Epidermis of spermo- 
of spermoderm. ep epidermis; / fibers. derm in surface view. X160. (K. 

X160. (K. B. WlNTON.) B. WlNTON.) 

readily stained by safranin, about a pear-shaped lumen. In surface 
view the cells with thickened tertiary membrane are recognized by their 
darker color. 

'2. Fiber Layer (/). Eight to fourteen layers of strongly thickened 
fibers with brown walls and contents form the bulk of the spermoderm. 

3. Spongy Parenchyma takes the place of the tube cells of the apple. 

4. Cross Cells, 5. Starch Cells, and 6. Inner Epidermis, also I»eri- 
sperm, Endosperm, Embryo, and Stem are much the same as in the 


Pears are preserved and dried in various ways for winter use. On 
the Continent, fruit of inferior grade, as well as the pomace from the 
manufacture of pear cider, is dried and ground for the preparation 
of various coffee substitutes and for adulterating spices and other food 

The elements of value in distinguishing pears from apples are the 

PEAR. 329 

window cells (Fig. 252, epi) of the epidermis (smaller than in the apple); 
the groups of stone cells (st 1 ) in the fruit flesh (rare in the apple); the 
endocarp cells (p 2 ) with broad lumen (narrow in the apple); and the 
isodiametric epidermal cells (Fig. 2526) of the spermoderm (longitudi- 
nally elongated and diagonally pitted in the apple). The warty, multi- 
cellular hairs (Fig. 252c) on the sutures of the carpels lack thick-walled 

Fig. 252c. Pear. Hairs from suture of endocarp. (Maifatti.) 

members. Crystals rosettes, so common in the apple flesh occur rarely 
in the pear. 


See General Bibliography, pp. 671-674: Hanausek, T. F. (10); Moeller (29); 
Schimper (37); Villiers et Collin (42); Vogl (45). 
Baillon: Sur le development des ovules des Pyrus. Bull. mens, de la soc. Linn, de 

Paris. 1875, 45. 
Garcin: Recherches sur l'histogenese des pericarpes charnus. Ann. Soc. nat. Bot. 

Ser.VII, 1890, 12, 175. 
Howard: Microscopical Examinations of Fruits and Fruit Products. U. S. Dept. Agr. 

Bur. Chem. Bull. 66, 103. 
Jxtmelle: Sur les graines a deux teguments. B. S. B. France, 1888, 35, 302. 
Malfatti: Beitrage zur Anatotriie der Birn- und Apfelfrucht. Ztschr. Nahr.-Unters. 

Hyg. 1896 10, 265. 
Nevtnny: Die Piment-Matta. Ztschr. Nahr.-Unters. Hyg. 1887, 1, 46. 




The quince (Cydonia vulgaris Pers., Pyrus Cydonia L.), although re- 
garded by some authorities as belonging to another genus, is closely 
related to the apple and pear. The tree is a native of central Asia, but 
is cultivated throughout the temperate regions of both hemispheres. 

The fruit of some varieties is apple-shaped, of others pear-shaped. 
Woolly hairs cover the surface of the immature fruit, but are loosely 
attached, and many of them either fall off during ripening or are rubbed 

Fig. 253. Quince {Cydonia vulgaris). Isolated elements of fruit, epi epidermis with t 
hair; hy hypoderm; fruit flesh elements: st l stone cell group, with p 1 radiating 
parenchyma containing am starch grains, p 2 irregularly thickened parenchyma, / 
fiber, bundle consisting of sp spiral, g pitted and ret reticulated vessels, si 1 stone cells 
accompanying bundle, p % spongy parenchyma and cr crystal cell of inner mesocarp; 
p* and p 6 parenchyma and ie inner layer of endocarp. X160. (K. B. Winton.) 

off by handling. The fruit has five cavities, like the apple and pear, 
but each contains 6-15 seeds arranged mostly in two crowded rows. 

Receptacle and Pericarp (Fig. 253). 1. The Epidermis (epi) consists of 
window cells (10-25 /") like those of the pear, brown cells about round 
openings, and hairs (t) with the walls usually thinner than the lumen. 

2. The Hypodermal Cells (hy) are of no special interest. 

3. Fruit Flesh. Several authors have cited the flesh of the quince 
as an example of stone cells in a parenchymatous ground tissue. The 
structure is even more remarkable than in the pear, as the groups (st 1 ) 



are usually larger, often several millimeters in diameter, more numerous, 
and the parenchyma cells radiating from them (p x ), except for occasional, 
irregularly thickened, isometric individuals (p 2 ) are usually more elongated. 
Small starch grains (am) occur in the parenchyma. The bundles con- 
tain the same elements as in the .apple. The inner portion of the fruit 
flesh consists of spongy parenchyma (p 3 ) with occasional cells containing 
twin crystals (cr). 

4. The Endocarp of the quince is similar to that of the pear, but 
the cells of the inner epidermis (ie) are narrower. Three kinds of hairs 
(Fig. 253a) occur in the sutures : 
(1) crooked, thick-walled forms 
like those of the epicarp, (2) thin- 
walled, one to several celled 
hairs and (3) jointed, branching, 
warty hairs, such as occur in the 

Spermoderm. 1. Epidermis 
(Fig. 254). The gelatinous sub- 
stance which surrounds the moist 
seeds originates in this layer. 
Mounted in glycerine the cellular 
structure is indistinct, but on 
addition of water the mucilaginous substance forming the inner or 
secondary membrane of the walls dissolves and the cells assume their 

normal, sharply prismatic form. 
The cells are often over 100 p. 
high and have thin, colorless 
primary walls. In tangential 
section they are isodiametric 
polygonal, but in fragments 
Fig. 254. Quince. Epidermis of spermodenr 1 obtained by scraping, owing to 
cross section and surface view. X160. their height, they often fall on 

(K. B. WlNTON.) ... .j j , , 

their sides and present the 
characteristic elongated appearance seen in cross section. 

2. Fiber Layer, 3. Cross Cells, 4. Starch Cells, and 5. Inner Epi- 
dermis resemble the corresponding layers of the apple. 

Perisperm. By treating cross sections with Javelle water, the outer 
cells of the compressed tissue forming the perisperm swell to their nor- 
mal shape. The thick cuticle evidently belongs to these cells. 

Fig. 2530. Quince. Epidermis of endocarp su- 
ture in cross section. t l thick-walled, / 2 thin- 
walled and t s warty jointed hairs; cr crystal 
rosette. X160. (K. B. Winton.) 

332 FRUIT. 

Endosperm and Embryo present the characters common to the group. 
Tschirch notes that the aleurone grains vary from 5.5-6.5 n and com 
tain globoids in considerable numbers. 


As quinces are more expensive than the other pomes, they probably 
never serve as adulterants. The microscopist may, however, be called 
upon to examine quince preserves for foreign pulp, or quince seeds 
(used in medicine because of their mucilaginous properties) for seeds 
of the .apple or other foreign seeds. 

The stone cell groups (Fig. 253, st 1 ) in the fruit flesh are often larger 
and more numerous than those of the pear, and are distinguished from 
other stone cells by the elongated parenchyma cells, which, even after 
cooking, form rosettes about the groups. Mounted in water, the thin- 
walled, prismatic epidermal cells (Fig. 254) of the spermoderm^ often 
100 /j. high, are unlike the epidermal cells found in the apple or pear. 
In surface view they are isodiametric. The crooked hairs (Fig. 253, t) 
of the epicarp resemble those of the raspberry, while those of the suture 
(Fig. 253a) are of three forms. 


See General Bibliography, pp. 671-674: Berg (3); Planchon et Collin (34); 
Tschirch (39). See also p. 329: Garcin; Howard. 
Bordzilowski: Ueber die Entwicklung der beerenartigen und fleiscbigen Friichte. 

Arb. Kiewer Naturf. Ges., 1888, 9, 65. 
Godfrin: Etude histologique sur les tegument seminaux des Angiospermes. Soc. 

d. Sci. d. Nancy, 1880, 109. 


Although the almond is commonly known as a nut, it is properly a 
drupe with the outer pericarp removed, or in common parlance, a "stone." 
The almond tree (Prunus amygdalus Stokes) is so closely related to the 
peach that some botanists regard it as but a variety of the latter developed 
by cultivation. According to Focke it is a native of Turkestan and middle 
Asia, but it is now cultivated not only in the Orient, but in southern Europe, 
northern Africa and California. 

The cultivated varieties fall into two classes: the sweet almonds (var. 
dulcis) including the hard and the paper-shelled varieties, and the bitter 

ALMOND. 333 

almonds (var. amara), the latter containing a glucoside, amygdalin, which 
through the agency of emulsin, another constituent, splits up into dex- 
trose, hydrocyanic acid, and oil of bitter almonds. In all the varieties, 
the outer pericarp at maturity is not fleshy as in the peach, but thin and 
leathery, splitting away from the stone along a longitudinal groove on one 
side of the fruit. The stone or unshelled almond is flattened, pointed at 
one end, of a buff color, and has a dull surface with numerous shallow pits. 
The outer part of the endocarp is not so hard as the inner, and is more or 
less separated from the latter by a zone containing the nbro-vascular 
bundles. Paper-shelled almonds, owing to the thin endocarp, are partic- 
ularly suited for table use. 

Although the ovary contains two ovules, only one of these usually 
develops into a seed. The latter is suspended in the cavity, being con- 
nected with a large bundle running between the two layers of the endo- 
carp. A conspicuous raphe passes from the hilum situated near the 
pointed or upper end of the seed to the chalaza at the lower or broader 
end, there separating into numerous branches. A thin brown spermoderm 
and a still thinner, colorless skin made up of perisperm and endosperm 
incloses the embryo, which consists of large cotyledons and a small radicle 
situated at the hilum end. 

The highly esteemed Jordan almonds from Malaga have long, narrow 
kernels, with light buff, smooth spermoderm. Other varieties, including 
Alicanti or Valencia almonds, have broadly ovoid, flattened kernels and 
a rough, dark-brown spermoderm. 


Endocarp. In the outer papery layers the ground tissue is made up 
of isodiametric, parenchyma and sclerenchyma cells with thickened walls 
pierced by circular pores. The bundles, which lie in a zone between this 
and the inner endocarp, contain numerous pitted vessels 10-15 I 1 broad 
and, rarely, spiral vessels. 

The inner or hard endocarp is thin, being but 0.5 mm. or less thick in 
paper-shelled, varieties. On the inner surface it is smooth but not lus- 
trous. The cells throughout are sclerenchymatized, but vary greatly in size 
and shape as well as in the thickness of the walls. Those in the outer layers 
are large, usually isodiametric, with walls only slightly thickened. Their 
circular or elliptical pores are small but very conspicuous. In the middle 
layers the stone cells are transversely elongated and rather narrow, with 
walls often thicker than the breadth of the lumen. Still narrower (seldom 

334 FRUIT. 

over 20 fi), elongated stone cells form the inner layers. They are for the 
most part longitudinally arranged and have walls so strongly thickened 
that the lumen is reduced to a narrow line. All have white or light yellow 
walls and colorless or light brown contents. 

The Spermoderm forms a thin brown skin with a finely granular outer 
surface. Cross sections should be examined directly in water and also 
after treatment with alkali, or, better still, with JaveHe water. 

1. Outer Epidermis (p. 335, I, ep and IT). Stone cells (60-400/;, 
usually over 100 pi) occur singly or grouped among the parenchyma cells. 
As seen in cross section (7, si) they are more or less rectangular, with 
moderately and uniformly thickened walls, commonly higher than broad 
and often elongated like trichomes. The outer end is free from pores 
but often cracked; the inner end is porous. Young finds in the paper- 
shelled almond, cells with rather thick walls but no stone cells. 

2. The Hypoderm includes two or three layers of brown polygonal 
cells without intercellular spaces. 

3. The Middle Layers (p) are of spongy parenchyma, through which 
pass the raphe and its branches, consisting of numerous spiral vessels, 
phloem elements, and crystal cells. 

4. Inner Epidermis (iep) . Although made up of small cells, this layer 
is distinct in cross section because of the brown contents. In surface 
view the cells are polygonal. 

Perisperm (N). From seeds soaked in water the perisperm and endo- 
sperm may be separated as a white inner skin. A hyaline layer of oblit- 
erated cells occurs in this as well as in the other common drupes. Treat- 
ment of sections with Javelle water brings out the outer layer of rect- 
angular cells with a cuticularized outer membrane. 

The Endosperm (E) consists of a single layer of aleurone cells with 
rather thick walls, and inner layers of obliterated cells. 

Embryo. The epidermal cells are elongated, the cells of the inner 
layers rounded. The small aleurone grains of the ground tissue are 
3-5//, the large solitary grains 10-15//, in diameter. Some contain 
crystalloids, others globoids, and still others, particularly the large soli- 
tary grains, calcium oxalate rosettes. 

Shelled Almonds. Kernels of the peach, apricot, and plum are com- 
mon substitutes, particularly in confectionery. The epidermal stone 
cells are larger and higher than in the apricot and plum. In cross sec- 

I and n Almond; III and IV Peach; V and VI Plum; VII and VIII Apricot. 

Left: Skin of Seed in Cross Section. S spermoderm consists of ep outer epidermis made up of paren- 
chyma and st stone cells, P ground tissue vnthfv fibro-vascular bundles and cr crystal, cells, and iep inner 
epidermis; N perisperm; R endosperm consists of al aleurone cells and * obliterated parenchyma. 

Right: Epidermis of Spermoderm in Surface View, st 1 stone cells with focus on outer wall; si 2 stone 
cells with focus on inner wall; st 3 chain of stone cells. 

X160. (K. B. Winton.) 

336 FRUIT. 

tion they are more or less rectangular, whereas in the apricot they are 
rounded and in the peach and the plum they taper. Further distinctions 
from the peach pit are the absence of a continuous layer of stone cells 
at the hilum (Hannig), of rows of small stone cells along the bundles, 
and of several layers of aleurone cells in the endosperm (Young), also 
the presence of cracks in the outer end of the stone cells (Hannig). The 
ends of the nerves do not have tree-like branches such as occur in apricot 
kernels (Hannig). Wittmack and Buchwald state that, although the 
stone cells of the almond and peach are commonly higher than broad, 
whereas in the apricot and plum they are broader than high, more de- 
pendence can be placed on the following physical characters : 

1. Almond. Agreeable taste, also strong odor on adding hot water char-* 
acteristic. Even bitter almonds lack disagreeably bitter taste. Spermoderm 
firm, leathery, light yellow-brown within. 

2. Peach. Kernels broadly ovoid, flatter than those of almonds, smaller 
than most almonds, sharply angled. Spermoderm very thin, brown within. 
Taste at first somewhat sweet, afterwards bitter. Odor, after treatment with 
hot water, sweet. 

3. Plum. Kernels rather long or broadly ovoid| thick, rounded at angles. 
Spermoderm as in peach. Taste like that of peach kernels, but bitter after-taste 
more disagreeable. Odor after scalding sweet, suggesting ripe plums. 

4. Apricots. Kernels broadly heart-shaped, flat. Spermoderm firm, leathery, 
within white and shining. Taste same as that of peach and plum kernels. Dis- 
agreeable, sweet odor on treatment with hot water. 

Almond Paste, consisting of the ground embryo, is used in preparing 
diabetic foods and macaroons. Pastes made from peach and apricot 
pits, often used as adulterants, usually contain fragments of the spermo- 
derm with the epidermal stone cells. 

Almond Cake, a by-product in the manufacture of almond oil, yields 
on grinding almond flour, used as a diabetic food, a cosmetic, and in 
Europe as an adulterant of ground spices and other powders. The 
tissues of the spermoderm, particularly the stone cells of the epidermis, 
are of chief importance in diagnosis. 

Almond Shells, like those of other fruit stones, are ground for adul- 
terating spices. The stone cells and vascular elements are easily found, 
but not so easily distinguished from similar elements of other shells. 


See General Bibliography, pp. 671-674: Berg (3); Collin et Perrot (9) ; Hanausek, 
T. F. (10, 16, 48); Meyer, Arthur (27); Moeller (29); Planchon et Collin (34); 
Vogl (45). See also pp. 329 and 332: Garcin; Godfrin. 

PEACH. 337 

Collin: Falsification des substances alimentaires par les coques d'amandes pul- 

v6ris6es. Journ. pharm. chim., 1905, 101. 
Garcin: Du noyau des drupes. Histologic et histogenese. Ann. d. 1. Soc. Bot. 

Lyon, 1890, 17, 27. 
Garctn: Contributions a l'etude des pericarpes charnus. Du noyau des drupes. 

Histologic et histologenese. Lyon, 1890. 
Hannig: Ueber die Unterscheidung der Mandeln von ahnlichen Samen. Ztschr. 

Unters. Nahr.-Genussm., 1911, 21, 577. 
Wittmack u. Buchwald: Die Unterscheidung der Mandeln von ahnlichen Samen. 

Ber. deutsch. bot. Ges. 1901, 19, 584. 
Young: A Study of Nuts, with Special Reference to Microscopical Identification. 

U. S. Dept. Agr., Bur. Chem., Bull. 160. 


Notwithstanding its specific name (Primus Persica Sieb. et Zucc), the 
peach is believed to be a native of China. It is a typical drupe, with 
a hairy epicarp, a fleshy mesocarp, and a dense, deeply furrowed stone 
or endocarp. The varieties in cultivation have yellow or white flesh, 
the outer portion, particularly in white peaches, often being suffused 
with red, as are often the fibrous layers adjoining the stone. The stone 
either clings to the flesh or is free. The seed is smaller than the almond 
and has a thinner spermoderm. 


Fresh or canned whole peaches may be hardened in alcohol for sec- 
tioning. The epicarp separates readily from the fully ripe fruit, espe- 
cially after scalding. Sections of the stone may be prepared with a 
strong razor, or by grinding on an oil-stone. 

Pericarp (Fig. 255). 1. The Epicarp (epi) elements are polygonal 
cells, stomata and numerous hairs (t), the latter forming a dense velvety 
coat. These hairs are exceedingly variable in length, many being mere 
papillae, while others exceed 1 mm. They are straight or slightly sinu- 
ous, 10-25 f- broad in the middle, tapering toward both ends, and are 
blunt pointed. Even the short forms are strongly devel&ped, the thick- 
ness of the walls usually exceeding the breadth of the lumen. The basal 
portions between the epidermal cells are exceedingly narrow (6-10 fi) . 
Separated from the epicarp, the hairs often appear double pointed. 

2. Hypoderm (hy).- Collenchyma cells in 4-6 layers. 

3. Mesocarp (mes). The cells are mostly large and sac-like. They 
often contain rosettes of needle crystals (cr 2 ). Smaller cells contain rosettes 



of the usual, oxalate type (cr 1 ). Reticulated, pitted, and spiral vessels 
occur in the bundles (fv) and, near by, rows of crystal rosette cells (cr 3 ) 
and elongated, thin-walled stone cells (st 1 ). Thick-walled fibers like 
those found in the apricot are rare. 

4. Endocarp. The hard, deeply furrowed shell of the peach stone 
is 3-8 mm. thick, of a light brown color. Although exceedingly hard 
throughout, it is easily split into halves by inserting a knife-blade through 
the suture, thus disclosing a prominent bundle entering the cavity near 
its upper end. A continuation of this bundle is the funiculus. There 

Fig. 255. Peach (Pmnus Pefsica). Isolated elements of pericarp, epi epicarp with 
t hairs; hy hypoderm; mes mesocarp cells with cr 1 oxalate crystal rosette and cr' 
rosettes of needle-shaped crystals; fv fibro-vascular bundle; cr 3 crystal cells and st 1 
stone cells accompanying bundle; sf- and st 3 stone cells of endocarp; iep inner laver 
of endocarp. X160. (K. B. Winton.) 

is no separation of the endocarp by a bundle zone into an outer and 
inner portion as in the case of the almond. 

The bulk of the stone consists of nearly isodiametric stone cells (si 2 ) 
often 50-75 fi broad, with thick, colorless, porous walls. The cell con- 
tents are usually brown, whereas in the plum they are colorless. Within 
0.5 mm. or less of the inner surface there is a layer 200-300 fi thick of 
narrow transversely elongated stone cells (sP) passing abruptly into an 
inner layer of narrow forms mostly longitudinally arranged (iep). 

Spermoderm (p. 335, 777 and IV). Hannig finds that the epidermal 
stone cells form a continuous layer at the hilum and that the outer wall is 


strongly thickened and free from pits and cracks. Wittmack and Buch- 
wald note that these stone cells taper toward the free end, whereas in the 
almond they are more or less rectangular. In addition to the large 
stone cells of about the same size as those of the almond, Young finds 
small ones (average 50 /x) in rows along the bundles (IV, st 3 ). 
Endosperm. Two or more layers of aleurone cells are present. 


The Pulp or flesh is not only eaten raw, but is dried and preserved 
whole, and is made into jam. It consists of thin-walled elements and 
bundles. The rosettes of needle crystals usually disappear on cooking. 
In preserves, even when made from the pared fruit, as is -almost always 
the case, fragments of the epicarp, or more commonly the detached hairs 
from this coat, are present in greater or less abundance. The hairs are 
characterized by their variable length, thick walls, and narrow base, 
whereas apricot hairs have a broad base. Apple pulp, and apple jelly, 
common adulterants, usually contain traces of gelatinized starch and 
sometimes tissues of the epidermis and core. 

The Endocarp in powder form consists largely of colorless stone cells 
with brown contents. 

The Seed is distinguished from shelled almonds as noted on p. 334. 


See pp. 329 and 337: Garcin; Godfrin; Hannig; Howard; Wittmack u. 

Buchwald; Young. 
Lampe: Zur Kenntniss des Baues und der Entwickelung saf tiger Friichte. Ztschr. 

Naturw.,"i886, 59, 295. 
Micko: Ueber den microskopischen Bau der Steinkerne von Amygdalus persica, 

Prunus armeniaca, domestica el avium. Ztschr. osterr. Apoth.-Ver. 1893, 31, 

2, 21. 


The apricot tree (Prunus Armeniaca L.), a native of central Asia, 
is cultivated in various parts of Europe, also extensively in California. 
The fruit is a drupe, very much like the peach in macroscopic structure, 
the chief difference being that the stone is nearly lenticular, about 20 cm. 
broad, and is merely roughened on the surface by shallow pits, whereas 
the peach stone is deeply furrowed. On the ventral suture is a promi- 
nent keel with a sharp edge, and either side of this keel a pronounced 
rib. Through the stone, beneath the suture, passes the bundle which 
enters the locule near the apex and passes into the funiculus. 



The more or less heart-shaped, flattened seed is but little elongated, 
the breadth often equaling or exceeding the length. 


Pericarp (Fig. 255a). The Epicarp hairs (t) are broadened at the base 
whereas those of the peach are narrowed. 

Mesocarp. The bundles and oxalate ro- 
settes are like those of the peach. Accompany- 
ing the bundles are characteristic thick-walled 
fibers (/). 

Endocarp. The stone cells have colorless 
or yellow contents. 

Spermoderm (p. 335). The epidermal 
stone cells are seldom over 100 ji broad and 
60 ijl high. The rounded outer walls are por- 
ous and somewhat thickened. Hannig notes 
the tree-like branching of the nerve ends. 


The epicarp hairs and mesocarp fibers are 
characteristic. The latter occur in preserves 
made with the removal of skin and pits. For 
Fig. 255a. Apricot (Pmnus distinctions of the seed from the almond, see 

Aimemaca). Epi epicarp 

with / hair; / mesocarp fibers p. 334. 

X160. (K. B. Winton.) ' 


See Bibliography of Almond, p. 337, and Peach, p. 339: Hannig; 
Micko; Wittmack u. Buchwald; Young. 



Numerous varieties of both the European plum (Primus domestica L.) 
and the Japanese species (P. trifiora Rxb.) are cultivated throughout 
the temperate zone. The European species includes red, blue, and 
yellow-green varieties, differing greatly in size and excellence. None of 
the Japanese varieties is blue or purple. 

Plums never have a hairy epicarp, thus differing from the peach and 
apricot. The stone is smaller than that of the apricot and more elon- 
gated, but otherwise is similar both in gross and minute structure. 


Pericarp. 1. Epicarp (Fig. 2556). The division of the mother cells 
into daughter cells is clearly evident. The walls are more or less dis- 
tinctly beaded. In the European plum the cells are seldom over 60 fi, 
in the Japanese varieties still smaller, rarely ex- 
ceeding 35 fi. The coloring matter of blue and 
red varieties is confined almost entirely to the 

2. Mesocarp. Characteristic are the strongly 
refractive masses accompanying the bundles 
which in making jam take up color from the 
epicarp. The bundles and neighboring thin- 
walled stone cells are like those of the peach; 
thick-walled fibers occur rarely. 

3. Endocarp. The stone cells have colorless FlG 2$sk pium {Pnmus 
contents. domestica). _ Epicarp in 

Spermoderm (p. 335, V and VI). The stone (K. b. Winton.) 
cells resemble those of the apricot, but the outer 

end is more strongly thickened, somewhat tapering, and has pits extending 
only part way through the walls. 

Endosperm. On the broad sides of the seeds there are 15-25 layers 
of aleurone cells, but on the narrow sides there is but one layer. 

Plums are commonly dried, or preserved in a wet way, with skins and 
stones, thus facilitating their identification. Prunes (dried plums), are 
sometimes used in coffee substitutes. The stone is smaller than that of 
the apricot, but similar in shape, external appearance, and anatomical 
structure. The absence of hairs on the epicarp furnishes a ready means 
of distinction from both the peach and apricot. 


See General Bibliography, pp. 671-674: Blyth (5); also see Bibliographies, 
pp. 337 and 339: Hannig; Howard; Micko; Wittmack u. Buchwald; Young. 
Bordzilowski: Ueber die Entwickelung der beerenartigen und fieischigen Friichte. 
Arb. Kiewer Naturf. Ges., 1888, 9, 65. 


The sweet or Mazzard cherry (Prunus avium L.), a native of Europe 
and western Asia, also the sour or Morello cherry (Prunus Cerasus L.), 

342 FRUIT. 

are both cultivated in numerous varieties, which are black, white,, or red, 
according to the nature of the coloring matter in the epicarp. 

Like the plum, the epicarp is smooth, but the cells are noticeably 
larger, seldom less than 35 //, often 100// in diameter; furthermore, 
the division of mother cells into daughter cells is not usually evident. 

Lampe: Zur Kenntniss des Baues und der Entwickelung saf tiger Friichte. Ztschr. 
Naturw. 1886, 59, 295. 


The fruits of the dog rose (Rosa canina L.) and other species are of 
some importance in Europe as drugs and as coffee substitutes. Rose 
fruits occur in American and Canadian screenings. 

The ovoid, lustrous, red, compound fruit, the size of a small grape, 
consists of a closed receptacle bearing on the inner hairy surface several 
dry drupes about as large as grape seeds, each with hard pericarp hairy 
at the base, thin spermoderm, inconspicuous endosperm, and large embryo, 
the structure resembling that of the strawberry nutlet. 


Receptacle. The polygonal outer epidermal cells with red contents ; 
and the hairs of the inner epidermis are the important tissues. The 
latter often reach the length of several millimeters, have thick walls and 
narrow lumen, and gradually taper toward the base so that when 
detached they are pointed at both ends. 

Pericarp. Sections are cut with a strong razor. 

1. The Epicarp Cells are longitudinally elongated, and are the only 
cells of the pericarp that are not sclerenchymatized. 

2. Hypoderm. One or more layers of longitudinally elongated (in 
cross section isodiametric), rather thin- walled cells form this layer. 

3. Large radially elongated Stone Cells constitute the middle layers. 

4. Longitudinal Fibers. These fibers are distinguished in cross sec- 
tion from the stone cells of the preceding layer by their small diameter 
and isodiametric form. 

5. Transverse Fibers in several layers are seen in cross section. Like 
the longitudinal fibers, they are exceedingly narrow. 

Spermoderm. Cross sections cut with the pericarp should be soaked 
for a time in Javelle water to expand and clear the tissues. Surface 
preparations are obtained by soaking in Javelle water and scraping. 


The Outer Epidermis is of polygonal cells (30-75 [i) in diameter, and 
the Inner Epidermis, of narrow (8-15 ft), transversely elongated cells of a 
brown color. The middle layers are either absent or obliterated. 

Perisperm. This is an obliterated tissue forming a hyaline mem- 
brane on the outer cells of the endosperm. 

Endosperm. One to several layers of cells containing aleurone 
grains, with often obliterated inner layers, constitute the thin endosperm. 

The Embryo tissues are like those of the strawberry (p. 347). 


The epidermal cells of the receptacle with red contents, the hairs 
pointed at both ends, the stone cells of the pericarp, and the thin-walled 
cells of the spermoderm are the chief diagnostic elements. 

See General Bibliography, pp. 671-674: Hanausek, T. F. (10); Villiers et Collin 


The varieties of strawberry cultivated in Europe are chiefly improved 
forms of Fragaria Chiloensis Ehrh., but some are said to be hybrids 
of this species with F. vesca L., or F. Virginiana Duchesne. In many 
parts of Europe, however, the small but delicious wood strawberry 
(F. vesca L.) is consumed in larger quantities, both fresh and preserved, 
than the cultivated sorts. 

In colonial times the wild strawberry (F. Virginiana), with its several 
varieties, was cultivated in American gardens, but of late years has been 
supplanted almost entirely by the numerous derivatives of the Chilian 
species, although wild strawberries are still gathered in considerable 
quantities in the meadows. F. vesca grows in the northern part of the 
United States, but it is not so common as the Virginian species. 

The cultivated strawberries (F. Chiloensis) are usually of large size 
(often 3-5 cm. in diameter), and bear the achenes in deep depressions. 

Berries of the wood species (F. vesca) are of small size (seldom over 
1 cm. in diameter) and bear the achenes in shallow depressions. 

Berries of the Virginian species are of about the same size as the 
wood strawberries, but like the cultivated berries, the achenes are deeply 
sunken in the receptacle. 

The receptacle, the edible part of the strawberry, consists of a some- 



what fleshy pith, a still more fleshy cortex, and between the two a narrow 
zone of fibro- vascular bundles, from which branches shoot off through 
the cortex to the achenes (Fig. 256, 7). 

On the surface, the receptacle has a tufted appearance, due to the 

Fig. 256. Strawberry (Fragaria Chiloensis). I aggregate fruit, X2. II achene, Xi. 
Ill achene, X8: Sty style; Sti stigma; B connecting bundle. IV achene in trans- 
verse section, X32: F pericarp; 5 spermoderm; R raphe; E endosperm; Em embryo. 

somewhat regularly arranged depressions occupied by the achenes. The 
epidermis is sparingly pubescent. 

The achenes are ovate, pointed, about i mm. long (Fig. 256, II and ///). 
Each is attached to the receptacle a little above its base, and contains 
a single anatropous seed, which is described as " exalbuminous," since 
the endosperm is not evident under the simple lens. The style (about 
2 mm. long) arises from the ventral side a little above the point of attach- 

The pericarp is hard and comparatively thick; the spermoderm soft 
and thin; the embryo minute (Fig. 256, IV). When the fruit reaches 
maturity the calyx is still green and leaf-like, and the stamens are also 
well preserved. The calyx, the stamens, and a portion of the pith are 
removed in preparing the fruit for the table. 


In microscopic structure the cultivated, the wood, and the Virginian 
strawberries are identical. 

Receptacle (Fig. 257). 1. The Epidermal Cells (ep) for the most 
part are polygonal and isodiametric, but those radiating from the base 
of each hair are usually irregularly diamond-shape, and often strongly 
elongated. The hairs are not numerous, but are often over a milli- 
meter long, tapering gradually from the widest part near the base to 


the point (h). In the basal portion the lumen is several times the thick- 
ness of the walls, but narrows somewhat abruptly further on, • and for 
fully three-fourths of the total length of the hair is but a narrow channel 

Fig. 257. Strawberry. Receptacle in surface view, ep epidermis with h hair and sto 
stoma; hy hypoderm; k glucoside (?) crystals. X160. (WlNTON.) 

hardly one-quarter as wide as the walls. The walls, on the other hand, 
are narrowest at the basal end. Stomata occur sparingly. 

2. Hypoderm or Sarkogen Layer {hy). Tschierske has shown that 
the fleshy receptacle of the strawberry owes its origin to a hypodermal 
layer of meristematic cells, which are mostly tangentially elongated, 
and are always without intercellular spaces. These cells, to which he 
gives the name "sarkogen layer," resemble the phellogen or cork- forming 
cells of other plants, but differ in that the new cells are formed centripe- 
tally and remain active during the whole period of growth, whereas the 
cork cells are formed centrifugally and die soon after formation. The 
cells increase in size in radial directions, and divide by tangential par- 
titions. After they have performed their mission they continue to increase 
in size, but hold to their original shape. 

3. Cortical Tissue. The daughter cells formed by the division of 
the cells of the sarkogen layer increase rapidly in size, become round 
in shape, and form intercellular spaces. This tissue forms the bulk 
of the ripe fruit. Each cell is rich in contents, which, on cooking or 
treatment with alcohol, yield a shriveled, opaque mass. 

4. Bundles. Spiral and annular vessels from 5-10 /x in diameter, 
and thin-walled, elongated cells, are the conspicuous elements of the 



5. Pith. Large berries often contain large intercellular spaces or 
cavities in the pith, formed by the tearing asunder of the cells during the 
rapid growth. 

Pericarp (Fig. 258). 1. Epicarp (epi). In surface view, the cells 
are polygonal, 15-50 /( in diameter, with thin walls. The cuticle is 
several times as thick as the radial walls of the cells. 

2. Mesocarp (mes). This layer 'is strikingly different from the meso- 
carp of most edible fruits in that it is not succulent, and consists of only 

Fig. 238. Strawberry. Achene in transverse section. F pericarp consists of epi epicarp, 
mes mesocarp, sp spiral vessels, k crystal layer, // outer endocarp with longitudinally 
extended fibers, and qj inner endocarp with transversely extended fibers; 5 spermoderm 
consists of ep epidermis with reticulated cells, and br elongated brown cells; N peri- 
sperm; E endosperm consists of a single layer of aleurone cells. X 300. (Wiirros.) 

one, or in some parts two, cell-layers. In cross section the cells have 
much the same appearance as the epidermal cells, but usually have 
smaller dimensions. On the inner side are numerous bundles, the branches 
of which run transversely about the achene. 

3. Crystal Layer (k). The cells are polygonal, 8-20 ,u in diameter. 
The monoclinic crystals are always simple. 

4. Outer Endocarp (If). This layer, forming the larger part of the 
pericarp, is made up of five or more thicknesses of sclerenchyma fibers 
longitudinally arranged. The cell-walls are distinctly porous and about 
as thick as the lumen. 

5. The Inner Endocarp (qj) consists of the same elements as the outer 
endocarp, but is only one or two cell-layers thick, and the cells are ar- 
ranged transversely. On the dorsal side some of the fibers of this layer 
extend radially through the outer endocarp, thus facilitating the rup- 
ture of the pericarp during sprouting. 



Spennoderm (Figs. 258 and 259). 1. The Epidermis (ep) is of thin- 
walled polygonal cells. The cell- walls are exceedingly thin, but are 
strengthened by spirally reticulated bands, which do not pass completely 
around the cell, but are wanting on the outer surface, so that in mounting 
a preparation the outer wall often collapses and the side walls fall down, 
presenting the appearance shown in Fig. 259. 

2. Brown Layer (br). The second layer of the spermoderm is com- 
posed of transversely elongated brown cells, often arranged side by side 

Fig. 259. Strawberry. Spermoderm 
and endosperm in surface view. 
ep reticulated epidermis of spermo- 
derm; br brown cells; E endosperm. 
X300. (WlNTON.) 

Fig. 260. Straw- 
berry. Style and 
stigma. X32. 

Fig. 261. Strawberry. 
Style in surface view, ep 
transparent epidermis; 
sp spiral vessels; k crystal 
cells. X 300. (Winton.) 

in rows. They vary up to 100 fi in length, and usually between 10- 
15 fi in width. 

Perisperm (N). This coat consists for the most part of obliterated 
cells forming a cellulose layer from 2-4 ft thick, but on the ventral side 
the cells are often well defined. 

Endosperm (E). This consists of a single layer of aleurone cells. 

Embryo. Two large cotyledons, each in cross-section semielliptical, 
make up the bulk of the embryo. The thin-walled cells contain pro- 
tein and fat but no starch. 

Style and Stigma (Figs. 260 and 261). The strawberry style is dis- 
tinguished from the styles of other edible rosaceous fruits by its constricted 
base and the large size and transparency of the epiderm cells. It is 
about 0.3 mm. in diameter in the middle part, but tapers somewhat toward 

348 FRUIT. 

the stigma, and very markedly toward the base, where it is less than 
o.i mm. in diameter. The epidermal cells (ep) are for the most part 
about 40 p. wide, 100-150 p long, and (as may be seen on the margins, 
by focusing) 50 ft thick. The central core appears darker than the 
transparent margins, owing to the greater density of the parts as well 
as to the greater thickness. Treatment with alkali discloses spiral and 
annular vessels, also rows of accompanying crystal cells (k), each con- 
taining a crystal rosette. 

Fungous growths often completely hide the papillae of the stigma, 
even after treatment with reagents or cooking. 


Styles and achenes may be readily picked out with forceps and exam- 
ined as to their size and shape under a lens. The styles (Figs. 260 and 
261), transparent in the fresh fruit, and rendered still more so by the 
boiling with sugar, may be studied under the compound microscope 
without further treatment. Their size (2 mm. long), narrow base and 
large transparent epidermal cells, are especially characteristic; but the 
spiral vessels accompanied by crystal clusters, and the stigma, .often 
bristling with fungous threads, further aid in the identification. Crystals 
are* clearly differentiated by the aid of polarizing apparatus. 

For the study of the pericarp and seed, cross sections (Fig. 258) should 
be prepared, holding the achene between pieces of soft wood or in a 
hand-vice during the cutting. Especially striking are the two crossing 
endocarp layers of sclerenchyma fibers, the endosperm of a single cell 
layer, and the relatively large embryo. The reticulated cells of the outer 
layer of the spermoderm are highly characteristic. 

The hairs (Fig. 257, h) of the receptacle are characterized by their 
length (often 1 mm.) and narrow lumen. 


See General Bibliography, pp. 671-674: Blyth (5). 
Keaus: Ueber den Bau trockner Pericarpien. Pringsh. Jahrb. 1866, 5, 83. 
Marpmann: Beitrage zur mikroskopischen Untersuchung der Fruchtmarmeladen. 

Ztschr. angew. Mikr. 1896, 2, 97. 
Tschierske : Beitrage zur vergleichenden Anatomie und Entwicklungsgeschichte einiger 

Dryadeenfriichte. Ztschr. Naturwissenschaft. 1886, 59, 594. 
Winton: Beitrage zur Anatomie des Beerenobstes. Ztschr. Unters. Nahr.-Genussm. 

1902, 5, 785. Conn. Agr. Exp. Sta. Rep. 1902, 288. 




Rubus Idaus L. occurs native in various part of the Old World and 
is the parent of the raspberries cultivated in European gardens. 

Bailey 1 states that the red raspberries cultivated in America are 
offspring of the native R. strigosus Michx., which, however, is closely 
related to the European raspberry R. Idaus L. The yellow varieties 
are but albino forms of these species. 

The raspberry, blackberry, and other bramble fruits (Rubus) are 
intermediate in both macroscopic and microscopic structure between 
the strawberry {Fragaria) and the stone fruits (Primus). They resemble 
the strawberry in that they are aggregate fruits with numerous indi- 
vidual fruitlets on a common receptacle (although unlike the straw- 
berrv, the cortex of the receptacle is not fleshy and bears the fruitlets 
on elevations, not in depressions); and they resemble the stone fruits 
in the structure of the pericarp and seed, each individual fruitlet 
being in fact a minature drupe. The resemblance between the rasp- 
berry drupelet and the peach is especially striking. In both the epi- 
carp is pubescent, the mesocarp is fleshy, the endocarp (Fig. 262, III 

Fig. 262. Red Raspberry (Rubus strigosus). I aggregate fruit, Xi. II cross section 
of a drupelet, X32: Epi epicarp; Hy hypoderm; Mes mesocarp; F outer endocarp; 
F' inner endocarp; 5 spermoderm; R raphe; E endosperm; Em embryo. Ill stone, 
Xi. IV stone, X8. (Winton.) 

and IV) is a hard stone with wrinkles on the surface and the united 
spermoderm and endosperm form a thin coat for the relatively large 
embryo. They are also very similar in minute structure, as is noted 
further on. 

1 The Evolution of Our Native Fruits. London, 1898, 287. 

35° FRUIT. 

The drupelets are crowded together on the top and sides of the recep- 
tacle, each having a convex top or exposed surface and four to seven 
facets on the sides formed by the pressure of the adjoining drupelets 
(Fig. 262, /). These facets are usually slightly convex or concave. Owing 
to their crowded arrangement the thickness of the flesh in the sides of 
the drupelets is much less than in the outer part. The exposed surface 
and the angles between the facets are pubescent, the facets themselves 
glabrous. In picking a raspberry the drupelets separate from the 
receptacle, clinging together in the form of a cup. Tschierske states 
that the individuals cling together, first because of the closely fitting 
adjoining facets, the slightly convex surface of one fitting into a cor- 
responding concave surface of another, and second because of the in- 
terlocking of the crooked hairs. The style is about 4 mm. long and 
arises from the upper edge of the exposed surface of the drupe, appear- 
ing to come from between the drupelets. 


Receptacle. 1. The Epidermis resembles somewhat the epicarp of 
the fruit, but the hairs are less numerous and usually thicker walled. 

2. Cortex. As no sarkogen layer is developed in the raspberry the 
cortex layer is thin, the bulk of the receptacle being pith. 

3. Bundles. It follows from what has been stated that the main 
bundles run near the surface of the receptacle. They are shorter and 
more strongly developed than in the strawberry, with larger and more 
numerous vessels. 

4. The Pith consists of round parenchyma cells, devoid of cell-contents, 
with intercellular spaces. 

Pericarp. 1. The Epicarp (Fig. 262, Epi; Fig. 263) on the facets of the 
drupelets consists entirely of polygonal cells, but on the exposed surfaces 
consists of polygonal cells and hairs, the hairs often being so numerous 
that they occur at two to four of the angles of the polygonal cells. Five 
or six cells frequently meet at the base of a hair, forming a rosette about 
it. The hairs vary greatly in length, up to 700 fi, and are seldom over 10 /t 
broad. Most of them have thin walls (0.5 to 1.5 ft) of nearly uniform 
thickness (h) ; but some of the longer forms have thick walls and a narrow 
lumen resembling the strawberry hair (h'). The thin-walled hairs are 
commonly sinuous. 

2. Hypoderm (Fig. 262, Hy). Two or more cell-layers of collen- 


chyma form the hypoderm, a water tissue serving to retard the evapora- 
tion of the fruit juice. 

3. Mesocarp (Fig. 262, Mes). The outer two or three layers of the 
mesocarp consist of isodiametric cells with intercellular spaces, inter- 
spersed with crystal cells; but further inward, at least in the thicker 
portion of the fruit, the cells are enormously elongated in radial directions 
and are without intercellular spaces. Tschierske points out that the 
succulent nature of the fruit results from the radial growth of cells, not 
as in the strawberry from the formation of numerous isodiametric cells by 
a meristematic layer. 

As in all the species of Rubus, cells with crystal clusters are common, 

Bto v 

Fig. 263. Red Raspberry. Epicarp with h' straight hair, h sinuous hairs, and sto stoma. 

X160. (WlNTON.) 

particularly near the base of the style. Reticulated cells occur in the 
inner layers adjoining the endocarp. 

4. Outer Endocarp (Fig 262, F; Fig. 264, //). Owing to the deep 
wrinkles, the thickness of this coat is exceedingly variable. As in the 
strawberry, the sclerenchyma fibers are longitudinally arranged and 
cross those of the inner endocarp at right angles. The fibers are a 
little narrower than in the latter fruit and in cross sections are usually 
elliptical polygonal, with the longer diameters in radial directions. 

5. Inner Endocarp (Fig. 262, F'; Fig. 264, qf). The fibers of this coat, 
of which there are four or more thicknesses, are the same as in the outer 
endocarp, but run transversely about the fruit. 

Spermoderm (Fig. 264, S). The seed coats of the bramble fruits 
resemble closely those of the stone fruits, the chief difference being that 
the epidermal stone cells are wanting. 

3S 2 


i. Epidermis (ep). The cells are polygonal in surface view, the average 
diameter being 35 [i and the maximum 70 /i. In transverse section they 
are cushion-shaped, with a cuticularized outer wall. 

2. Nutritive Layer (p). The cells in this layer, having fulfilled their 
mission, are empty and are often more or less collapsed. 

Fig. 264. Red Raspberry. Endocarp and outer portion of seed in cross section. End 
endocarp consists of If longitudinally extended fibers and }/ transversely extended 
fibers; 5 sperraoderm consists of ep epidermis, p parenchyma (nutritive layer), and iep 
inner epidermis; JVperisperm; E endosperm with k aleurone grains. X300. (\Vinton.) 

3. Brown Layer {iep). The inner layer of the spermoderm consists 
of cells of the same kind as in the outer epidermis, but only about half 
as large, the maximum diameter in surface view being 30 ,u and the average 
20 fi. These cells' are readily distinguished from those of the neighbor- 
ing layer by their thicker walls and yellow -brown color. 





Perispenn (Fig. 264, N). As in the strawberry, all that remains of 
this tissue is the layer of obliterated cells, which in section appears as the 
thickened outer wall of the endosperm. 

The Endosperm (Fig. 264, E) is made up of aleurone 
cells with remnants of other cells adjoining the embryo. 
On the two broader sides of the elliptical section there 
are five or six cell-layers, but the number diminishes 
toward both the ventral and dorsal sides, where there 
are only two or three. 

Embryo (Fig. 262, Em). The structure of the 
embryo is practically the same as in the strawberry. 

Style (Figs. 265 and 266). 1. The Epidermal Cells 
(ep) are much smaller than in the strawberry, and 
owing to numerous wrinldes on the surface are not so 
transparent. These wrinkles may be brought out 
clearly either by treating specimens with iodine as 
recommended by Tschierske, or better, by bleaching 
with Javelle water and staining with safranin. On the 
broadened basal portion of the style are scattering 
hairs like those of the epicarp. 

2. Bundles. After heating the style with dilute 
alkali, the vessels (sp) and accompanying isodiametric 
crystal cells (k) are clearly evident. 


Styles and stones (seeds with inclosing endocarp) 
are evident to the naked eye. 

The styles (Figs. 265 and 266) may be examined 
directly under the microscope as in the case of the 
strawberry, and are identified by their length (4 mm.), 
broadened base with hairs, and small, wrinkled epider- 
mal cells. Vessels and crystal cells are also striking 

The stones (Fig. 262, III, IV) are distinguished 
from seeds of other genera by their characteristic 
wrinkled surface and from blackberry stones by their 
smaller size. Cross sections (Fig. 264) show the two 
layers of endocarp, the spermoderm with cells of the 
outer epidermis twice the diameter of those of the inner epidermis, the 
endosperm of several cell layers, and the embryo. 


Fig. 265. Raspberry. 
Style and stigma. 
X32. (Winton.) 

354 FRUIT. 

The epicarp (Fig. 263), the hairs of which are mostly blunt, narrow 

(10 pi), thin-walled, and sinuous, also the crystal cells of the underlying 

mesocarp, may be readily found in mounts prepared 

iffli^yifflHi from the gelatinous portion of the product. The 

1 H hairs are easily distinguished from those of the 

'|af|p---k peach and apricot which are broad (10-25 /*)> 

m ' fffiSS— - sp nearly straight, and have walls thicker than the 

I^BB^^ breadth of the lumen. Vascular elements are almost 

entirely wanting, as the receptacle is not picked 
Fig. 266. Raspberry. . , , , . 

Style in surface view. With the fruit. 
ep epidermis; sp spiral 

vessel; k crystal cells. BIBLIOGRAPHY. 

X 300. (Winton.) See General Bibliography, pp. 671-674: Villiers et Collin (42). 

Marpmann: Beitrage zur mikroskopischen Untersuchung der Fruchtmarmeladen. 

Ztschr. angew. Mikr. 1896, 2, 102. 
Tschterske: Beitrage zur vergleichenden Anatomie und Entwickelungsgeschichte 

einiger Dryadeenfruchte. Ztschr. Naturwissenschaft. 1886, 59, 612. 
Winton: Beitrage zur Anatomie des Beerenobstes. Ztschr. Unters. Nahr.-Genussm. 
1902, 5, 785. Conn. Agr. Exp. Sta. Rep. 1902, 288. 


Rub us occidentalis L., a native of the northern United States, is 
the parent of the black varieties. It differs from the red raspberry 
chiefly in the smaller size of the drupelets and their deep purple-black 
color, due to the dark claret-red cell juice. The pits of both are about 
the same size and shape. 

The black raspberry has practically the same microscopic structure 
as the red species. 

Black raspberry jam or preserve is of a deep claret-red color and 
the seeds are stained the same color. 


Rubus jruticosus grows wild in various parts of Europe, but is sel- 
dom cultivated. 

In North America three native species are of importance: the tall 
blackberry (R. nigrobaccus Bailey), the short cluster blackberry (R. nigro- 
baccus var. sativus Bailey), and the dewberry, or running blackberry 
(R. villosus Aiton). These are not only common wild plants, but have 
given rise to numerous cultivated varieties. 1 

1 Bailey: The Evolution of our Native Fruits. London, 1898, 366, 379. 



In macroscopic and microscopic structure the berries of all the species 
named are practically alike. 

The blackberry agrees with the raspberry in general structure, but 
differs in the following details: (i) The drupelets are glabrous or, in 


Fig. 267. Blackberry (Rubus nigrobaccus). Outer layers of pericarp in surface view. 
epi epicarp with sto stoma; hy hypoderm; k crystal cells. X160. (Winton.) 

the case of the dewberry, sparingly hairy. (2) The drupelets are firmly 

attached to the receptacle by broad bases and do not separate from the 

latter on picking the fruit. There is really no 

epidermis of the receptacle as the surface is 

almost completely covered by the bases of the 

drupelets, the epicarp of one being continuous 

with that of the adjoining drupelet. (3) As may 

be seen from Fig. 268, the pits resemble those 

of the raspberry in shape and markings, but 

are much larger. (4) The styles (Fig. 269) are 

but 2 mm. long and commonly arise from a marked depression in the 

drupelet. They are free from hairs and do not broaden at the base. 

Fig. 268. Blackberry. 
Stone, X 1 and X 32. 


Receptacle. The structure of the receptacle differs in no essential 
detail from that of the raspberry. 

Pericarp (Fig. 267). 1. Epicarp (epi). The cells are for the most 
part elongated, the longer diameters extending in latitudinal directions 
on the sides of the drupelets, and in concentric circles about the styles. 
Stomata are always present, hairs never in R. nigrobaccus, seldom in 
R. villosus. 



2. Hypoderm (hy). As in the epicarp, the cells are commonly elon- 
gated, but are much larger and extend in longitudinal directions. 

3. Mesocarp. This layer is much the same as in the raspberry. 
Crystal clusters (k) are numerous, especially near the surface. 

4. Endocarp. As in the raspberry, the sclerenchymatized fibers of 
the endocarp have secondary and tertiary membranes and run longi- 
tudinally in the outer, and latitudinally in the inner 
layer. Both coats, however, are thicker than in the 
raspberry, the inner consisting of 6-10 cell-layers. 

Sperm oderm. It has been noted that the outer 
epidermis of the raspberry spermoderm is made up of 
polygonal cells with about twice the diameter of those 
in the inner epidermis. The reverse is true in the case 
of the blackberry, the spermoderm being much the 
same as a raspberry spermoderm turned inside out. 
The average diameter of the outer epidermal cells is 
about 25/1, the maximum 40 ji, whereas the average 
diameter of the inner epidermal cells is 40 /j. and the 
maximum 60 ,«. 

Style (Fig. 269). The epidermal cells are about 
the same size as in the raspberry, but are not wrinkled 
to any appreciable extent. Hairs are entirely wanting. 
Crystals and vessels are conspicuous in alkali prepa- 


Fig. 269.. Blackberry 
Style and stigma 
X32. (Winton.) 

Examination of blackberry preserves is made as 
h ! ! described under raspberry. Styles (Fig. 269) are less 

numerous than in the latter and are distinguished by 
their shorter length, and the absence of hairs and wrinkles. In cooked 
products it is not usually evident that the styles arise from a depression 
in the drupelet. The seeds (Fig. 268) are larger than in raspberries, but 
in histological structure are very similar. They are, however, distin- 
guished from the latter by the thicker inner endocarp and by the fact that 
the cells of the outer epidermis of the spermoderm are about half the 
diameter of those of the inner epidermis; whereas, in the raspberry the 
reverse is true. In blackberry preserves, unlike that made from rasp- 
berries, hairs are few or entirely absent; but tissues of the receptacle, 
notably the vascular elements, are present. 

Compared with the strawberry, the bundles are shorter but more 


strongly developed, with larger and more numerous vessels. Elongated 
epidermal cells and crystals clusters are also distinguishable. 

The loganberry, a cross between the raspberry and blackberry, has 
epidermal hairs similar to those of the raspberry, but with thicker walls. 
The style is of the blackberry type. 

See p. 332 (Godfwn) ; p. 339 (Lampe); and p. 354 (Winton). 


The bush fruits of this family yield many-seeded berries, wi h 
withered remains of the floral parts at the extremity. The epicarp is 
either smooth (red currant), glandular (black currant), or prickly (some 
species of gooseberry). Only in the currants is the endocarp sclerenchy- 
matized. The seeds are characterized by the large inflated epidermal 
cells, and the crystal layer of the spermoderm, the bulky thick-walled 
endosperm containing aleurone grains, and the minute embryo. 


Both the red and white garden varieties of currant are derived from 
the European species, Ribes rubrum L. 

The calyx tube is united with the ovary, and the fruit (a true berry) 
bears on the summit the shriveled remains of the floral parts (Fig. 270, 
/). The deeply five-cleft bell-shaped calyx tube bears in its throat five 
petals much smaller than the calyx lobes and alternating with them, and 
five stamens opposite the lobes. The short style, about half the length 
of the calyx, is deeply two-cleft. The midribs of each of the floral envelopes, 
ten in number, are continued in the fruit in the form of longitudinal veins, 
and are clearly seen through the transparent epicarp. The anatropous. 
seeds, one to eight in number, are borne on two parietal placentas (Fig. 
270, II). As a result of the crowded arrangement they are usually flattened 
on one or more sides. The outer spermoderm (Fig. 270, III, S) is gelat- 
inous and transparent, and through it may be seen the delicate thread- 
like raphe and the brown hard inner spermoderm. The minute embrya 
(Fig. 270, III, Em) is embedded in the base of the endosperm. 

358 FRUIT. 

Divested of the gelatinous c"oat the seeds are from 4 to 5 mm. long and 
from 3 to 4 mm. broad (Fig. 270, IV and V). 

Pericarp (Fig. 271). 1. Epicarp (epi). In parts the walls are thick- 
ened with narrow pores; in other parts the walls are not thickened at 


FlG. 270. Red Currant (Ribes rubrum). / f;uit, Xi. 7/ cross section of fruit with seeds, 
Xi. /// longitudinal section of seed, X8: 5 gelatinous epidermis of spermoderm; 
S' inner spermoderm; R raphe; E endosperm; Em embryo. IV seed deprived of 
gelatinous coat, Xi. V same as IV, X8. (Winton.) 

all, or only here and there. Frequently strongly beaded cells are divided 
by thin partitions into two daughter cells. Stomata are numerous. Cross 
sections show that the cells are considerably broader than thick. 

PlG. 271. Red Currant. Outer layers of pericarp in surface view, epi epicarp with sto 
stoma; hy hypoderm; B vascular bundle or vein seen through the transparent outer 
layers of the fruit. X160. (Winton.) 

2. Hypoderm (hy). Two or three cell layers of collenchymatous cells 
underlie the epidermis. In surface view they are polygonal with diam- 


eters twice or more those of the epidermal cells. Their collenchymatous 
character is seen in a cross section. 

3. Mesocarp. The cells are isodiametric (100 -300 /*), with thin 
walls and numerous intercellular spaces. Radiating from the bundles 
are elongated cells. Crystal rosettes abound in the inner layer. 

4. Endocarp (Fig. 272). Unlike the gooseberry, the currant has a 
sclerenchymatous endocarp. The long cells are arranged in groups, each 

Fig. 272. Red Currant. Endocarp in surface view. X160. (Winton.) 

group consisting of five to fifteen cells side by side. The cells of adjoin- 
ing groups may extend either in the same or different directions. Curious 
fan-shaped forms result from the junction of several groups. As a rule 
the cavity is much thinner than the walls and oftentimes is reduced to a 
mere line. Numerous pores connect adjoining cells and some pierce the 
walls separating these cells from the mesocarp. The cells range in length 
up to 500 p.; the thickness of the double walls is 5-20 p.. 

Spermoderm (Fig. 273, S). 1. Mucilage Cells (aep). The outer 
layer consists of large, thin-walled cells filled with gelatinous matter. 
They are about 90 p. in tangential diameter but often have a radial diam- 
eter of over 500 [i. On the outer surface they are usually convex. Owing 
to the great size of the cells, this coat, although but a single cell-layer 
thick, forms a considerable part of the bulk of the seed. 



2. Parenchyma (p). Beneath the mucilage cells are several layers 
of more or less flattened parenchymatous cells with intercellular 
spaces. The cells of the inner layers are smaller and flatter than in the 

3. Crystal Layer (Figs. 273 and 275, k). In surface view the deep 
brown, thick-walled cells of this layer are sharply polygonal with diam- 

FlG. 273. Red Currant. Seed in cross section. 5 spermoderm consists of aep gelatinous 
outer epidermis, p parenchyma (nutritive layer), k crystal layer, and iep brown layer 
(inner epidermis); 2V perisperm; E endosperm. X300. (Winion.) 

eters from 8 to 20 ,u. The middle lamella is colorless, the thick mem- 
brane, brown. Each cell contains a single monoclinic crystal, which 
nearly or completely fills the cell cavity. 

With crossed Nicol prisms these crystals appear as luminous spots in 
the black background, disappearing on addition of a drop of hydrochloric 
acid. In section it may be seen that only the radial and inner walls are 
thickened, and that as a consequence each crystal lies close to the thin 
outer wall. 

4. Inner Epidermis (Figs. 273 and 275, iep).. Like the crystal layer, 
the inner epidermis is of a deep-brown color, but this color is due to cell- 
contents, not to thickened cell-walls. The cells are longitudinally elon- 
gated, varying in length up to 150 p and in width from 4 to 9 /*. Both 
this layer and the crystal layer are readily separated from the endosperm 
by soaking in dilute alkali and scraping. 



Perisperm (Fig. 273, N). A cross section of the seed shows a cellulose 
band about 10 ft thick between the spermoderm and the endosperm, 
consisting of the obliterated cells of the nucellus. 

The Endosperm (Figs. 273 and 275, E) consists of thick- walled cells 
containing aleurone grains and fat. In the outer layers the cells are 
radially elongated, with walls of even thickness (2 fi), but in the center of the 
seed they are isodiametric, often with knotty thickened walls (Fig. 274). 


Cells of the endocarp (Fig. 272) are the most conspicuous and char- 
acteristic elements of preserves. Fragments of the epicarp and floral 
parts are also evident but are of less value in identification. The outer 
gelatinous coat of the seed is destroyed by cooking, but the crystal layer 
and the inner epidermis retain their 
original form and may be identified 
in surface mounts (Fig. 275) prepared 
by warming in dilute alkali and 

Fig. 274. Red Currant. Cross sec- 
tion of central portion of endo- 
sperm. X 300. (Winton.) 

Fig. 275. Red Currant. Surface view of K 
crystal layer, iep inner epidermis of spermo- 
derm, and E endosperm. X 300. (Winton.) 

scraping with a scalpel. Sections of the seed are sometimes useful, but 
as a rule an examination of the spermoderm in surface view is sufficient. 


See General Bibliography, pp. 671-674: Blyth (5); Villiers et Collin (42). 
Garcin: Recherches sur l'histogenese des pencarpes charnus. Ann. Soc. nat. Bot. Se"r. 

VII, 1890, 12, 175. 
Lampe: Zur Kenntniss des Baues und der Entwickelung saftiger Friichte. Ztschr. 

Naturwissenschaft. 1886, 59, 295. 
Wtnton: Beitrage zur Anatomie des Beerenobstes. Ztschr. Unters. Nahr.-Genussm. 

1902, 5, 785. Conn. Agr. Exp. Sta. Rep. 1902, 288. 




The Black Currant (Ribes nigrum L.), a native of the Old World, is 
cultivated both in Europe and America. 

In external appearance the fruit is distinguished from the red currant 
by its black color and by the longer floral parts. The seeds are some- 
what smaller and more numerous (about 15 in each berry) than in the 
red varieties. 

The calyx is about 7 mm. long, and the lobes are reflexed. On 
the outer surface and on the inner surface at the ends the lobes are 
clothed with numerous hairs; but the throat is smooth, as are also the 
petals and the style. The latter is entire for at least three-fourths its 
length, but two-lobed at the end. 

The cells of the Epicarp (Fig. 276, epi) are beaded and of about the 
same size as in the red currant. Here and there are bright-yellow disc- 

Fig. 276. Black Currant {Ribes nigrum) . epi epicarp with d gland, in surface view. X160 


shaped glands (d) which often exceed 170 ,« in diameter. Meyen noted 
that they occur in still greater numbers on the leaves, and that they agree 
in structure with the glands of the hop. Each gland consists of a single 
layer of cells in the form of a disc, joined in the middle to the epicarp 


by means of a short several-celled stalk. The yellow oily secretion to 
which the plant owes its characteristic odor and flavor is contained in 
the reservoir formed by the separation of the outer cuticle from the cells. 

The Mesocarp, Endocarp, and Seed have the same general structure 
as the same parts of the red currant. 

Under the microscope the calyx hairs have the same appearance 
as those on the epicarp of the raspberry. They are crooked, blunt- 
pointed, thin-walled, and vary in length up to 600 a. 


Black currant preserves, jams, etc., have a red-black color, and the 
characteristic spicy flavor of the fresh fruit. They are further distinguished 
from similar products made from red currants by the glands on the epi- 
carp (Fig. 276,) the longer floral parts, the hairs on the outer surface of 
the calyx, and the smaller seeds. 

The mesocarp, endocarp, and seed tissues of the red and black cur- 
rant are the same in structure. 


Lampe: Zur Kenntniss des Baues und der Entwickelung saftiger Friichte. Ztschr. 

Naturw. 1886,. 59, 295. 
Meyen: Secretionsorgane d. Pflanzen. Berlin, 1837. 
Winton: Beitrage zur Anatomie des Beerenobstes. Ztschr. Unters. Nahr.-Genussm. 

1902, 5, 785. Conn. Agr. Exp. Sta. Rep. 1902, 288. 


The European or prickly gooseberry (Ribes Grossularia L.) is one 
of the most valuable small fruits cultivated in Great Britain and the 
Continent,- but is seldom grown in America owing to the mildew to which 
it is there, subject. The varieties cultivated in the United States are 
largely derived from a smooth fruited native species, R. oxyacanthoides L. 

The fruit has much the same general structure as the currant, but is 
larger (1 to 2 cm. in diameter), the calyx and style are longer (6 mm. in 
length), and are pubescent, and the smooth or prickly pericarp is thicker 
(Fig. 277). The gelatinous coat of the seed is thicker (often 2 mm. 
thick on the raphe side), but the seed freed from this coat is about the 
same size as in the currant, although somewhat narrower and more nearly 
terete. Except for the prickles, the European and American gooseberry 
are identical in structure. 

3 6 4 



Pericarp, i. The Epicarp Cells are polygonal and more 
beaded like those of the red currant. 

The Prickles have a broad base and are often over i mm. long 
have a blunt point, others, a head of globular 
form. Both forms are shown in Fig. 278. 

The Epidermal Cells of the prickles are elon- 
gated, and are arranged end to end in longitudinal 
rows. At the base they pass into the isodia- 
metric cells of the epicarp. 

2. The Hypoderm is the same as in the red 

or less 

Fig. 277. American Gooseberry (Ribes oxyacan- 
thoides). I whole fruit, Xi. 77 transverse sec- 
tion of fruit with seeds, X 1. 777 seeds deprived 
of gelatinous coat, X 8. (Winton.) 

Fig. 278. European Gooseberry 
{Ribes Grossularia). Prickles 
with and without globular head. 
X32. (Winton.) 

3. Mesocarp. This layer is composed of extraordinarily large cells 
(often 500 fi in diameter), which are evident to the naked eye and are 
separated from each other by a network of cells hardly 50 fi in diameter. 
In the inner layers the small cells are less numerous or entirely lacking. 
Crystal clusters are abundant, particularly in the inner layers. 

4. The Endocarp consists of a layer of parenchyma cells with walls 
so thin that they are studied with difficulty, and is quite different from 
the sclerenchymatous endocarp of the currants. 

Spermoderm, Endosperm, and Embryo. The microscopic structure of 
the seed is practically the same as that of the currant seed. 

Floral Parts (Fig. 279). The remains of the floral parts are usually 
deep brown, and can be studied to advantage only after bleaching, prefer- 
ably with Javelle water, and staining. A prominent midvein runs from' 
the base almost to the apex of each of the calyx and corolla lobes. 
About four secondary veins branching near the base, partly from the 
calyx midrib, partly from the corolla midrib, also run nearly to the- 



apex of the calyx lobes. Lateral branches from the midribs are numer- 
ous in the corolla, less so in the calyx. 

The epidermal cells of the calyx are for the most part slightly elon- 

FlG. 279. Gooseberry. Floral parts. X5. 

Fig. 280. Gooseberry. Epider- 
miSj from margin of calyx, with, 
hairs. X160. (Winton.) 

gated, and are arranged end to end in longitudinal rows. Near the ends 

of the lobes they have wavy outlines. The outer surface of the calyx 

and the upper part of the inner surface bear only a 

few scattering hairs. The calyx throat, however, is 

densely pubescent. These hairs are all thin-walled, 

and vary in length up to i mm. or more, the longest 

being in the calyx throat (Figs. 280 and 281). 

The deeply parted styles are covered with epider- 
mal cells, for the most part quadrilateral and arranged 
end to end in rows, and on the lower half bear 
numerous thin- walled hairs 1 mm. or more in length. 


The epidermis, mesocaip, and seed have the same 
structure as the corresponding parts of the currant, 
but the endocarp is not sclerenchymatized and is 
not evident in preserves. The floral parts (Fig. 279) 
are of about the same length as in the black currant 
(6 mm.), but the calyx throat and the styles bear Fig. 281. Gooseberry. 
numerous long hairs (Fig. 281), whereas these parts in tr^oaT^calyx/with 
the black currant are smooth, or only sparingly hair - X I(5 °- (Wm- 

366 FRUIT. 


See General Bibliography, pp. 671-674: Blyth (5). 
Garcin: Recherches sur l'histogenese des pencarpes charnus. Ann. Soc. nat. Bot. Ser. 

VII, 1890, 12, i 7S . 
Marpmann: Beitrage zur mikroskopischen Untersuchung der Fruchtmarnieladen. 

Ztschr. angew. Mikr. 1896, 2, 97. 
Winton: Beitrage zur Anatomie des Beerenobstes. Ztschr. Unters. Nahr.-Genussm, 

1902, 5, 785. Conn. Agr. Exp. Sta. Rep. 1902, 288. 


The fruits are either several-celled berries, each cell containing a 
number of seeds (cranberry, blueberry), or ten-celled drupes (huckle- 

The smooth epicarp bears short triangular calyx teeth. Groups of 
stone cells occur in the mesocarp of the huckleberry, but are lacking in 
the mesocarp of the other species. The endocarp in the cranberry is 
of thin- walled elements; in the blueberry, of thin- walled cells interspersed 
with groups of stone cells; in the huckleberry, of a dense mass of stone 
cells. The spermoderm of the cranberry and blueberry is characterized 
by the elongated, thick-walled, porous cells. 


Bailey 1 states that the cranberry {Vaccinium macrocarpon Ait.), the 
most unique of American horticultural products, was first cultivated, 
or rescued from mere wild bogs, about 1810. The varieties now known 
are over a hundred, all having been picked up in bogs, and the annual 
product in the United States is more than 800,000 bushels. 

The cowberry, or mountain cranberry, Vaccinium Vitis-Idcsa L., is 
gathered in great quantities in Canada, where it is used for sauces. It 
is also a native of Europe, where it is much prized as a culinary fruit. 

Different varieties of the cultivated cranberry vary in shape (spherical, 
oval, pear-shaped), in color (pink, red, maroon, mottled), and in size 
(diameter up to 15 mm.). 

The epicarp is smooth, and bears on the summit four short tooth- 
like calyx lobes, which are usually bent inward. Between the calyx lobes 

1 The Evolution of Our Native Fruits. London, 1898, 414, 424. 



is a circular spot with a dot in the center, formed by the dropping of the 
floral parts (Fig. 282, I). 

The berry is four-celled, each cell containing on a central placenta 
a number of seeds which fill only a small part of the otherwise empty 
cavity (Fig. 282, II). 

In the nearly ripe fruit only the epicarp is colored, the other parts 
being white; but in the fully ripe fruit all the tissues are usually red. 

FlG. 282. Cultivated Cranberry (Vaccinium macrocarpon). I berry seen from above, 
Xi. II cross section of berry, Xi. /// seed, X8. IV cross section of seed, X15: 
5 epidermis of spermoderm; S' inner spermoderm; R raphe; E endosperm; Em 
embryo. (Winton.) 

The yellow short-beaked seeds have a thick spermoderm and a bulky 
endosperm in the axis of which is an elongated embryo of moderate size, 
consisting chiefly of the radicle (Fig. 282, III and IV). 

The mountain cranberry has practically the same macroscopic structure 
as the cultivated species, but is much smaller. 


The following description applies to both the cultivated and the moun- 
tain cranberry, the two being nearly, if not quite, identical in microscopic 

Pericarp. 1. The Epicarp (Fig. 283) is very simple in structure, 
with cells as seen in surface view from 20 
to 50 [i in diameter, and cell-walls 3 /i thick. 
Cross sections show that this layer is about 
25 [i thick and that the cuticle is strongly 

2. The Hypoderm (Fig. 283) is for the 
most part only one cellrlayer thick, and the 
cells are more or less isodiametric in cross- 
section. Evaporation is largely prevented by 
the thick cuticle, rendering a more strongly 
developed hypoderm unnecessary. 

3. The Mesocarp cells are mostly isodiametric, and range up to 

Fig. 283. Cultivated Cranberry. 
Epicarp and hypoderm. X160. 

368 FRUIT. 

200 n in diameter, but in the partitions between the fruit cavities they are 
somewhat smaller. 

4. Endocarp (Fig. 284). The cells are for the most part longitudi- 
nally extended and are more or less curved or wavy in outline. The in- 

FiG. 284. Cultivated Cranberry. Endocarp with stoma. X160. (WlNTON.) 

distinctly porous cell- walls are somewhat thicker than those of the meso- 
carp, but unlike those in some Vaccinium species are not conspicuously 
thickened. Although stomata are entirely lacking in the epicarp, they 
occur in considerable numbers in the endocarp. 

Spermoderm. 1. Epidermis (Fig. 285, ep; Fig. 286). Of all the 
tissues, this is the most characteristic and remarkable. The cells in the 
mature seed range in width up to 100 ji, and in length up to 400 n, but 
in abortive seeds are much smaller. As is seen in cross section, the 
outer walls (Fig. 285, ep) are thin and convex, but the deep-yellow or 
brown inner and radial walls are sclerenchymatously thickened (double 
walls often 20 p.), and in addition the radial walls and sometimes the 
outer and inner walls have a transparent mucilaginous layer of distinctly 
stratified structure which nearly fills the cell cavity. Treated with chlor- 
zinc iodine the mucilaginous formation is stained blue, the cell-walls 


3 6 9 

proper remaining yellow. In V. Vitis-Idcea the outer and inner walls 
often have a swollen layer (Fig. 287). The sclerenchymatous radial 

— ep 

— m 

— B 

Fig. 285. Cultivated Cranberry. Seed in cross section, ep epidermis of spermoderm 
with sclerenchymatized and mucilaginous layers; m inner spermoderm; E endosperm. 
X160. (Winton.) 









Fig. 286. Cultivated Cranberry. Epidermis of spermoderm in surface view. X160. 


and inner walls are pierced with numerous pores which, in the immature 
or abortive seeds, are nearly circular, but in the fully ripe seeds are usu- 
ally much elongated. 

37° FRUIT. 

2. Inner Layers (Fig. 285, m). The remainder of the spermo- 
derm consists of two or three layers of large thick-walled porous cells, 
the innermost layers being more or less collapsed. In dried or cooked 
specimens, all of these cells are collapsed. 

The Endosperm (Fig. 285, E) contains aleurone grains but no starch. 

The Embryo is not remarkable. 


Fragments of the epicarp (Fig. 283) and endocarp (Fig. 284), 
bundles from the mesocarp, and seeds, may be found in preserves. The 

large porous epidermal cells of the spermo- 
derm, with sclerenchymatized and mucilage 
layers are characteristic and may be studied 
in surface preparations (Fig. 286). In un- 
ripe or abortive seeds these cells are smaller, 
Fl °- 28 7-. M ^ nt H^ ran r^ thinner-walled, and have pores more nearlv 

(Vaccmium Vttts-idcza). Cross > in- 

sertion of spermoderm. x 160. round than in the mature seeds. Isolated 

stone cells detached from the spermoderm 

of immature seeds by cooking, sometimes occur in the gelatinous portion 

of the preserve. 


Wnsriox: Beitrage zur Anatomie des Beerenobstes. ZtschrL Unters. Nahr.-Genussm. 
1902, 0, 785. Conn. Agr. Exp. Sta. Rep. 1902, 288. 


Vaccinium Myrtillus L. grows over an extended area in Europe, and 
the berries are used both as food and as medicine. 

Among the American species yielding edible berries similar to those 
of the European species are the tall or swamp blueberry (V. corymbosum 
L.) and two dwarf species (V. Pennsylvanicum Lam. and 1'. Canadense 
Kalm.), all of which are being introduced into cultivation. 

The berries of all the species named are black with a -gray-blue bloom, 
globular, 1 cm. or less in diameter, and are crowned by five calyx teeth. 
Except for the bloom they are hardly distinguishable in external appear- 
ance from the huckleberry, which they further resemble in flavor, but 
in internal structure the two fruits have little in common. The dense 
endocarp tissue of the huckleberry is represented in the blueberry by 
a thin and soft, although partially sclerenchymatized, tissue; furthermore, 



the locules of the former fruit contain but one seed, whereas in the latter 
they are several -seeded. On the other hand, the blueberry and cran- 
berry, although strikingly different in color and flavor, are very similar 
both in gross and minute anatomy. 


The important European and American species have practically the 
same structure. 

Pericarp. 1. The Epicarp consists of polygonal cells like those of 
the cranberry, but the contents are dark violet instead of red. 

2. The Hypoderm of collenchyma cells is of no special interest. 

3. Mesocarp (Fig. 288). The cells are for the most part thin-walled, 
but here and there, especially near the bundles, the walls are sclerenchy- 

Fig. 2 

Blueberry (Vaccinium Myrtillus). Endocarp and mesocarp in surface view. 
(R. Muller.) 

matized without being greatly thickened. Thick-walled stone cells, such 
as occur in the mesocarp of the huckleberry, are entirely wanting. Crystal 
clusters abound in the inner layers. 

4. Endocarp (Fig. 288). This tissue, consisting of a single thin layer 
of loosely united stone cells, is intermediate between the parenchyma- 
tous endocarp of the cranberry on one hand, and the thick stone -cell tissue 
of the huckleberry endocarp on the other. These stone cells separate 
readily from one another and are remarkable for their diversity of size 

1 Based largely on R. Miiller's exhaustive paper on the histology of the European 

37 2 FRUIT. 

and shape. Elongated cells, 15-50 ji in breadth, usually predominate, 
although isodiametric forms are also common. Among the elongated 
cells are distorted L-, S-, and Y-shaped, as well as various grotesque, 
forms. Quite as variable are the isodiametric cells, which are triangular, 
quadrilateral, rounded, or exceedingly irregular with curious horn-like 

Spermoderm. 1, The Outer Epidermis (Fig. 289) is of large elon- 
gated cells, the inner halves of which are strongly sclerenchymatized 

Fig. 289. Blueberry. Epidermis of spermoderm in surface view. (R. MtJuEH.) 

and porous. Except for the absence of the mucilaginous inner layers of 
the walls, the structure is like that of the corresponding coat of the cran- 

2. The Ifiddle Layers are of parenchyma cells, and 

3. The Inner Layers of obliterated elements forming in cross section 
a hyaline band. 

Endosperm and Embryo contain aleurone grains and fat. 


The epidermis of polygonal cells, the curious stone cells of the endo- 
carp (Fig. 288), and the whole seeds with the sclerenchymatized epider- 
mis (Fig. 289), are easily found in preserves and similar products. The 
absence of large stone cells in the mesocarp and of a dense endocarp in- 
closing each seed, as well as the structure of the seed itself, distinguishes 
the fruit from the huckleberry, while the dark color of the cell-contents 
and the presence of the curious endocarp stone cells furnish a ready 
means of distinction from the cranberry. 




Garcin: Recherches sur l'histogenese des pericarpes charnus. Ann. Soc. nat. Bot. Ser- 

Vn, 1890, 12, 175. 
Lampe: Zur Kenntniss des Baues und der Entwickelung saftiger Frtichte. Ztschr. 

Naturw. 1886, 59, 295. 
Muixer v Blau: Fructus Myrtilli. Pharm. Post, Wien. 1902, 35, 461. 


This wild berry (Gaylussacia resinosa Torr. and Gray) is abundant 
in the northern United States, and furnishes large quantities of fruit for 
the market. 

The fruit is globular in form, blue-black in color, and 1 cm. or less 
in diameter (Fig. 290, / and II). It is not a true berry, but a ten-celled 
drupe, the hard coverings of the so-called seeds 
being the inner walls of the pericarp cells. The 
epicarp is smooth and the fruit is crowned 
with five-pointed'calyx lobes much like those 
of the cranberry. In the center, between these 
lobes, is a small depression, the scar of the 
style. The pits are closely crowded about 
the axis, and as a consequence are wedge- 
shaped (Fig. 290, III and IV). Under the 
hand lens they have a rough granular appear- 

Within the thick endocarp is the seed with 
a thin spermoderm and a bulky endosperm; 
in the axis of the endosperm is an elongated 

Fig. 290. Hucklebenv {Gaylus- 
sacia resinosa). 1 fruit seen 
from above, Xi. II cross 
section of fruit, Xi. Ill 
stone, X8. IV cross section 
of stone, X 8: End endocarp; 
5 spermoderm; £ endosperm; 
Em embryo. (Winton.) 


Pericarp. 1. Epicarp (Fig. 291, epi). Surface mounts show the 
cells of this layer to be much the same in form and size as those of the 
cranberry epicarp; cross sections, however, show that the cuticle is much 

2. The Hypoderm (hy) is several cell layers thick, and thus furnishes 
a protection against evaporation, which is not necessary in the case of 
the cranberry, owing to its thick cuticle. 



3. Mesocarp (mes). Owing to the presence of numerous stone cells 
(s/) this layer is strikingly different from the mesocarp of the other com- 

f — epi 


FIG. 291. Huckleberry. Cross section of outer portion of the pericarp, ept epicarp; 
hy hypoderm; mes mesocarp; st stone cells. X160. (WlNTON.) 

Fig. 292. Huckleberry. Cross section of endocarp and seed. End endocarp with large 
isodiametric stone cells and // narrow longitudinally extended fibers; 5 spermoderm; 
N perisperm; £ endosperm. X160. (Winton.) 

mon small fruits, but resembles that of the quince and pear, although 

the stone cells are thinner-walled and the parenchyma cells about them 



are not strongly elongated, and are not arranged in a marked radiating 
pattern. These stone cells are angular or elliptical and vary in diameter 
up to 200 jx. The walls (20 ft or less thick) are pierced with numerous 
small pores. They occur either singly or in groups throughout the 
mesocarp, and may be readily separated from the soft tissues by 

4. Endocarp (Fig. 292, end). Most of the elements of this hard 
coat are stone cells, about the same size and shape as those of the meso- 
carp (although usually thicker-walled), but in the wall adjoining the 
mesocarp there is a group of narrow sclerenchyma fibers running parallel 

Fig. 293. Huckleberry. Spermoderm in surface view. X300. (WiNTON.) 

with the axis of the fruit and similar fibers form the inner layer of the 

The pits of the huckleberry crush more readily between the teeth than 
those of the bramble fruits, owing to the larger size of the stone cells and 
the relatively larger cell cavities. 

376 FRUIT. 

Spermoderm (Fig. 292, 5). There is but one layer of cells in this 
coat, which may be removed after cutting off the endocarp and studied 
in surface view (Fig. 293). Most of the cells are of fantastic form with 
wavy outline, and often reach a length of 200 p. The walls are beauti- 
fully reticulated, the nearly circular pores being 4 ,u in diameter. This 
coat is highly characteristic. The raphe is not conspicuous. 

The Endosperm (Fig. 292, E) and Embryo are much the same in 
structure and form as those of the cranberry. 


The characteristic elements of the huckleberry which may be found 
in preserves are the large stone cells of the mesocarp (Fig. 291) and 
endocarp (Fig. 292), and the reticulated cells (Fig. 293) of the spermo- 
derm. Stone cells of the mesocarp are distributed throughout the pre- 
serve, but those of the endocarp are obtained in transverse sections of 
the "seeds." The spermoderm is best seen in surface preparations. 


WrNTON: Beitrage zur Anatomie des Beerenobstes. Ztschr. Unters. Nahr.-Genussm. 
1902, 5, 785. Conn. Agr. Exp. Sta. Rep. 1902, 288. 


The fruits of this family are many-seeded berries differing in size 
and flavor but much alike in structure. The following detailed descrip- 
tion of the orange suffices for an understanding of the group. 


The orange {Citrus Aurantium L.) is the most valuable citrus fruit 
and may be styled the apple of subtropical regions. It was introduced 
into Europe from the Far East at an early period and thence into America 
in colonial times. Before the days of rapid transportation the fruit was 
unknown in cooler regions except as a greenhouse product; now, how- 
ever, it is on sale throughout the civilized world. 

Two marked varieties are recognized, the common sweet orange 
(var. Sinensis Engler) and the bitter orange (var. amara L.). 

The fruit is a berry with normally 10 two-seeded locules, but as a result 
of cultivation the number of locules varies from 6-1 2 and the number of 
seeds also varies, being entirely absent in the navel varieties. The outer 



rind is of a deep orange color and consists of epicarp, hypoderm, and 
outer mesocarp. In this tissue are numerous cavities, often over i mm. in 
diameter, in which is secreted an 
essential oil consisting largely of a ter- 
pene, limonene, with small amounts 
of citral and other substances. The 
pimples on the surface of the fresh 
fruit, becoming depressions on drying, 
mark the position of these cavities. 
The inner rind or inner mesocarp is 
white and of much the same texture 
as blotting-paper. Each of the seg- 
ments of the fruit is covered by a 
membranous skin, the endocarp, 
while the fleshy part is made up of 
club-shaped vesicles springing from 
the inner surface of that portion of 
the endocarp adjoining the rind. 
Each of the seeds consists of two or 
more (maximum 12) embryos in- 
closed within a skin consisting of 
spermoderm, perisperm, and rem- 
nants of endosperm. Owing to the 
mucilaginous outer layer of the spermoderm the seeds are slimy 

Fig. 294. Orange (Citrus Auranliuni). 
Cross section of outer layers of peel from 
an unripe fruit. Ep epicarp with st stoma; 
scb oil cavity; gf fibro-vascular bundle; 
kr crystals of calcium oxalate; He lumps 
and crystals of hesperidin. (TsCHIECH 
and Oesterle.) 


Fresh ripe oranges are usually obtainable at all seasons and in all 
countries. Lacking these, alcoholic material may be used, and with the 
advantage that the tissues are hardened and the crystals of hesperidin are 
better defined. 

Pericarp (Fig. 294). Transverse and tangential sections of the rind 
and surface mounts of the skin covering the segments should be studied, 
also preparations obtained by crushing the isolated vesicles of the fruit 
pulp under a cover-glass. 

1. The Epicarp Cells {Ep) are rather thick- walled, sharply polygonal, 
and from 10-25 P- m diameter. Division of the mother cells into daughter 
cells is often evident. Beautifully formed stomata nearly circular in 
outline occur in considerable numbers; the epidermal cells about each 
stoma being more or less concentrically arranged. The color of the 



orange rind is due to chromatophores present not only in the epidermis 
but in the subepidermal layers and also in the vesicles of the pulp. 

2. Hypoderm. This tissue consists of rather small collenchyma 
cells in which ground tissue are the oil cavities (scb). These latter con- 
tain yellow drops of essential oil secreted by the delicate cells lining the 
cavity. In the cells of the ground tissue are numerous needle-shaped 
crystals of a glucoside, hesperidin (He), which, in alcoholic specimens, 
occur in dense spheroidal aggregates. Hesperidin is very abundant in 
the green fruit of all varieties, but diminishes in amount on ripening. 
The amount present at maturity in the sweet orange is, however, much 
greater than in the fruit of the bitter variety, a distinction of some value 
in the examination of marmalades. Cells here and there contain single 
monoclinic crystals of calcium oxalate (kr). 

3. Mesocarp (Fig. 295). The close tissue of the hypoderm passes by 
degrees into a colorless spongy parenchyma which makes up the white 

Fig. 295. Orange. Spongy parenchyma from inner layers of peel. (Berg.) 

tissue forming the larger part of the rind and the middle layers of the 
partition walls through which the segments separate. Owing to the large 
intercellular spaces and the narrow arms of the cells, this tissue presents 
a striking appearance in tangential section, and is also noticeable in 
the debris found in marmalades. 

4. Endocarp. The membranous skin or endocarp inclosing the seg- 
ments consists of greatly elongated, narrow cells transversely arranged. 
These are for the most part thin-walled, but individuals here and there 
have sclerenchymatized walls pierced by oblique pores, making the tissue 
especially noticeable in marmalades. 

5. Vesicles (Fig. 296). Tschirch and Oesterle find that in the 
green fruit two forms of multicellular hairs occur on that portion 



of the endocarp adjoining the rind; one, club-shaped with smooth sur- 
face, the other more or less knob-shaped with glandular epidermal cells 
forming an aggregate resembling a bunch of grapes. The former develop 
into the fruit vesicles, while the latter remain small and are not noticeable 
in the mature fruit. The vesicles are thread-like at the base, broadening 
into the distended and elongated bodies containing the fruit juice. The 
outer layer of these consists of narrow, fiber-like cells, the walls of which, 
although usually thin, occasionally are thickened like the sclerenchyma 
cells of the endocarp. In the inner portion of the vesicle the cells are 

Fig. 296. Orange. Multicellular hairs from inner surface of pericarp of an unripe fruit. 
These develop later into the fruit vesicles. (Tschiech.) 

larger and more isodiametric in form. The yellow color is due to 
chromat ophores. 

The Spermoderm may be studied in cross sections of the entire seed, 
also in preparations obtained by stripping off the outer and inner layers. 

1. Outer Epidermis. The sclerenchyma cells are 12-20 /: broad, 350- 
400 fi long, and 100-225 J" high> tne latter dimension not including the 
mucilaginous outer walls which often swell to a thickness of over 150 /z, 
forming a structureless hyaline lay er about the seed. Being elongated 
both longitudinally and radially, in surface view they appear like fibers, 
in cross section like palisade cells. The outer ends of the sclerenchy- 
matized portions are of various curious shapes, appearing in cross section 

3 8o FRUIT. 

like beaks projecting into the outer mucilaginous layer. The walls are 
narrower than the cavity and are distinctly porous. 

2. The Middle Spermoderm forms a close tissue in the layers adjoining 
the epidermis, passing into a spongy parenchyma further inward. 

3. Inner Epidermis. The cells are elongated and contain a brown 


Perisperm. Several layers of rather thick- walled cells form a tissue 
resembling the aleurone cells of various oil seeds. 

The Endosperm is either not evident at all or only as an obliterated 
structureless membrane. 

Embryo. According to Tschirch and Oesterle, only one of the several 
embryos is a product of the embryo sac, the others being formed in the 
outer layers of the nucellus at the end of the ovule without special fertiliza- 
tion. The nucellar embryos are none of them so well developed as the 
one formed in the embryo sac, only two at the most being capable of 
sprouting. The cells contain rounded aleurone grains from 2-10 /i in 
diameter, with numerous globoids. 


Orange Marmalade usually contains slices of the rind. Under the 
microscope we note the sharply polygonal epidermal cells, also the 
cells of the hypoderm containing numerous orange-colored chromato- 
phores. Needle-shaped crystals of hesperidin are often found distributed 
in the outer rind, especially if the marmalade was made from the common 
or sweet orange. After soaking for some time in alcohol they are 
evident as spherical aggregates as well as isolated raphides. The oil 
cavities (Fig. 294, scb) are macroscopic objects. 

The spongy parenchyma (Fig. 295) of the inner mesocarp, char- 
acterized by the narrow arms of the cells and the large intercellular 
spaces, is easily found in the de"bris, notwithstanding the thinness of the 
walls and the absence of color. 

Other characteristic elements are the fiber-like cells of the endocarp, 
some of which are sclerenchymatized, and the elongated epidermal cells 
of the vesicles, united into a thread at the base. 

Orange seeds are occasionally found in marmalades. Their shape, 
the presence of more than one embryo and otiier macroscopic characters 
usually suffice for their identification. Under the microscope the scleren- 
chymatized epidermal cells, both radially and longitudinally elongated, 
are the most conspicuous features. In cross section the outer beak- 


like extremities extending into the swollen, apparently structureless, 
mucilaginous layer, identify them beyond doubt as seeds of a citrus 

An examination of orange marmalade should include a search under 
the microscope for the pulp of cheaper fruits and vegetables. All the 
common citrus fruits have practically the same structure. Adulteration 
of one with the other is improbable. 


See General Bibliography, pp. 671-674: Blyth (5); Hanausek, T. F. (16); Hassall 
(19); Planchon et Collin (34); Tschirch u. Oesterle (40). 
Moeller, H. J.: Unterscheidung von Cortex Aurantii fructus und Apfelsinenschalen. 

Arch. Ph. og. Ch. 28, 369. 
Strasburger: Das Botanisches Practicum. 


The lemon {Citrus medica L. var. Limon L.) differs from the orange 
in color, shape, and flavor, but not in microscopic structure. The seed 
seldom contains over three embryos and often only one. 


Biermann: Beitrage zur Kenntniss der Entwickelungsgeschichte von Citrus vulgaris 

Risso und anderen Citrus-Arten. Arch. d. Pharm. 1897, 235, 19. 
Ross: On the structure and development of the lemon. Bot. Gazette, 1890, 15, 262. 


The citron (Citrus medica L. var. genuina Engler) is much larger 
than the lemon, being often 15-18 cm. long and 8-10 cm. broad. TFhe 
thick rind of the green fruit (2-4 cm.) is candied for use in cakes and 

In cross section the cells are nearly circular, forming a loose paren- 
chyma tissue with oil cavities near the outer surface. The epidermal 
cells are the same as those of the orange and lemon. 

Possible substitutes are the rind of the water-melon and other 

382 FRUIT. 


The Old World grape (Vitis vinijera L. order Vitacea), a native of 
the East, has been cultivated since time immemorial in Europe, and 
within the past half century has been successfully introduced into Cali- 

There are innumerable varieties differing in size, shape, and color of 
the berries, as well as in their flavor, acidity, and wine value. Aside from 
their use for wine production, the fresh berries are among the most de- 
licious of table fruits and the dried berries or raisins are everywhere 
common sweetmeats. 

Xanti currants are the dried seedless berries of a grape (V. vinijera 
var. apyrena L.) grown in the Ionian Islands and neighboring regions. 

Excepting those raised in the Pacific States, American grapes are 
largely derivatives of V. Labrusca L., V. oestivalis Michx., V. rotundijolia 
Michx., and other native species, although some are hybrids with 
V. vinijera. The northern fox grape (V. Labrusca) is the parent of the 
Concord, Hartford, and others of the most valuable varieties. Berries 
of the American varieties are more valuable as table fruit and for 
preserves than for wine-making. 

The morphology of both the fruit and the tissues is practically the 
same in all the European and American grapes, excepting the Xanti 
currant and other seedless varieties. The berry has a smooth epicarp 
(often with a bloom), a pulpy mesocarp, but lacks a conspicuous endo- 
carjD. Each of the two locules normally contains two seeds, but often 
only one, or in the case of the Xanti currants, none at all. The seeds 
(Fig. 297, A) are pear-shaped, 5-8 mm. long. On the ventral side are two 
longitudinal grooves penetrating into the tissues of the endosperm. Be- 
tween these runs the raphe, extending from the hilum at the narrow end 
of the seed over the apex or broad end to the chalaza situated on the 
dorsal side near the apex, its position being marked by an oval depression. 
The reserve material is largely in the form of horny endosperm. In 
cross section, owing to the grooves on the ventral side, the endosperm 
is mushroom-shaped. The minute embryo situated in the narrow end 
of the seed may be isolated after soaking for some days in ij per cent, 




The Pericarp of the grape lacks throughout characteristic tissues, 
thus facilitating the identification of foreign matter with marked character- 
istics. Sections are easiest prepared from fully formed but not fully 
mellowed berries, hardened in alcohol. 

1. Epicarp. The cells are polygonal, 15-40 fi in diameter, without 
any characteristic features. Cross sections show that the outer wall is 
about 7 ft thick with a roughened cuticle. 

2. The Hypoderm Cells are tabular and increase in size from with- 
out inward, passing finally into the pulp cells of the mesocarp. 

3. The Mesocarp or fruit flesh consists of thin-walled pulp cells and 
.fibro-vascular bundles. Howard notes that needle-shaped crystals are 

present, also crystal fibers attached to 
the bundles. The vascular elements of 
most of the bundles are entirely spiral 
vessels, but the larger bundles, par- 
ticularly of the European grape, often 
contain in addition pitted elements.. 

4. Endocarp. There is no sharply 
differentiated endocarp, the cells being 
thin- walled with the same general char- 
acters as those of the mesocarp. 

Spermoderm (Fig. 297). Seeds of 
any variety of European or American 
grape or of raisins may be studied, as 
observations indicate that all are the 
same in structure. Surface mounts are 
prepared of the outer and inner spermo- 
derm and cross-sections of the entire 
seed. The latter should be bleached 
with Javelle water and stained with 
safranin to bring out the inner layers 
of the spermoderm. 

1. Outer Epidermis (B, ep). Seen 
in surface view, the somewhat elon- 
gated cells are from 20-60 fi broad, 

Fig. 297. Grape {Vitis vinifera). A, I 
seed, ventral side with chalaza, natural 
size; II dorsal side with hilum, X2. 
B cross section of spermoderm show- 
ing ep outer epidermis, pa parenchyma 
with ra raphides, sc sclerenchyma layer 
and iep inner epidermis. C, D, scleren- 
chyma layer of Malaga grape in surface 
view and cross section. (T. F. Hanatj- 

and have thin colorless walls. Cross sections show that the outer wall is 
thickened and cuticularized. 

384 FRUIT. 

2. A Parenchyma (B, pa) of thin- walled cells forms a subepidermal 
coat, which over most of the surface is from 2-6 cell-layers thick, but 
in the grooves is thicker. Many of the cells contain bundles of beauti- 
fully formed raphides, evident both in cross sections and in surface 
mounts. The inner layers are often colored brown. 

3. Stone-cell Layer (B, se; C; D). This exceedingly hard coat 
makes up by far the greater part of the spermoderm. It varies in thick- 
ness from less than 75 ft to over 500 //. In the grooves it bends sharply 
and extends much deeper into the endosperm than does the parenchyma. 
Here, however, the layer is thin, often less than 75/4, whereas the paren- 
chyma over it is thicker than in other parts of the seed. At first sight 
the dense brown tissue appears to consist of a single layer of enormously 
elongated radially arranged cells forming a palisade layer, but on careful 
examination it is clear that only in the thinner portions is there but a 
single layer, the thicker portions consisting of an aggregate of moderately 
elongated or even isodiametric stone cells arranged end to end in radial 
rows. All of these cells have strongly thickened walls and narrow cavities. 

4. Lattice Cells. This cell-layer is obtained with some difficulty by 
cutting open the seed, picking out the endosperm, and scraping the inner 
surface of the spermoderm with a scalpel. The cells are for the most 
part longitudinally elongated, exceedingly narrow (6-10 /z), and have 
numerous small but very distinct spiral reticulations, giving them a lat- 
ticed appearance. In cross section the layer appears like a thin brown 
line of a darker color than either the stone cells or the inner epidermis, 
but on bleaching with Javelle water and staining, the reticulations are 

5. Inner Epidermis. Quite as remarkable as the lattice cells and 
much easier to find, are the cells of this layer. They are polygonal, 
12-35 I- 1 m diameter, and have yellow, porous radial walls, which in surface 
view are 4-5 /j. broad and very distinctly beaded. 

Perisperm. A hyaline band of obliterated cells is evident in cross 

Endosperm. The cells are rather small, seldom exceeding 40 p., 
and have moderately thick but distinct walls. Sections mounted in tur- 
pentine serve for the study of the remarkable aleurone grains which have 
been described by Tschirch, Liidtke, and others. The large, irregularly 
spherical, solitary grains reach 25 fi in diameter, and inclose either an 
oxalate rosette 5-10 n in diameter, or a large globoid. The numerous 
small grains are 3-6 /< in diameter. 

GRAPE. 3 8 5 

The Embryo is so minute and so encased in hard tissue that it is 
difficult to study. It has no characters of diagnostic importance. 


Grape Preserves contain either the whole fruit or only the skin and 
fruit flesh, both of which lack distinctive characters. The epidermal 
cells are polygonal, resembling those of the currant, plum, and many 
other products, and the pulp cells are not characteristic. Most of the 
vascular elements of the bundle are spiral vessels. Calcium oxalate 
raphides occur in greater or less abundance. 

The seeds (Fig. 297, A) are recognized by their pear-shaped form, the 
two grooves on the ventral side and the hilum depression on the dorsal 
side near the apex. Cross sections of the endosperm are mushroom- 
shaped. The characteristic tissues of the spermoderm (B) include the 
crystal-bearing parenchyma, the brown stone cells, the lattice cells, and 
the yellow, beaded inner epidermis. The soli- 
tary aleurone grains of the endosperm and the 
oxalate rosettes and globoids are also worthy 
of notice, the rosettes appearing most distinct 
after the proteid matter has been dissolved in 
dilute alkali. 

Raisins are used in cakes, sweetmeats, etc., 

either whole or chopped, with or without the 

seeds. The cellular elements are the same as 

Fig. 298. Kaism. Section of 

have been noted under preserves. Sugar crystals fruit flesh showing crystals 
(Fig. 298) often separate in the cells, and are ° sugan <■ OGL -' 
seen after mounting in alcohol or some other medium in which they are 
not soluble. 

Xanti Currants contain the same elements as the grape and raisin, 
except that they lack fully developed seeds. Brown abortive seeds are 
always present. 

Grape Pomace and other refuse from the wine-presses have been 
utilized in various ways, both as food for the lower animals and as adul- 

Ground Grape Seeds serve as adulterants of coffee and possibly of 
other products. They are easily identified by the characters already 


See General Bibliography, pp. 671-674: Hanausek, T. F. (10, 16); Villiers et Collin 
(42); Vogl (45)- 

3 g 6 FRUIT. 

Howard: Microscopical Examinations of Fruits and Fruit Products, U. S. Dept. Agr, 

Bur. Chem., Bull. 66. 103. 
Lampe: Zur Kenntniss des Baues und der Entwickelung saftiger Friichte. Ztschr. 

Naturw. 1886, 59, 295. 
Schuler: Studien tiber den Bau und die Zusammensetzung der Traubenbeere. - Die 

Weinlaube, 1880, 34. 


According to De Candolle, the fig tree (Ficus Carica L. order Arto- 
carpea) grew wild in prehistoric times in a subtropical belt extending 
from Syria on the east to the Canaries on the west. It was cultivated 
in very early times in Egypt, Palestine, Greece, and Rome, and at later 
periods was introduced into France, Spain, Persia, India, and finally, 
in the eighth century, into China. Its culture in America dates from 
Colonial times, and is now an important industry in California and some 
of the southern states. 

The numerous minute flowers are borne on the inner surface of a 
fleshy pear-shaped receptacle, communication with the outer air being 
through an opening or eye in the broad end. They are of four kinds : 
1. Staminate flowers with five-parted perianth and four stamens, pro- 
duced in considerable numbers only in the wild fig (caprifig, goat fig, 
Latin, caprijicus). 2. Fertile pistillate flowers, also known as seed flowers, 
with three- to five-parted perianth and a long style. The inflorescence 
of the Smyrna fig and other cultivated sorts is largely or entirelv of these 
flowers, caprification (fertilization) being effected only bv the pollen of 
the wild fig, which is carried to the fertile flowers by a wasp breeding in 
the latter variety, hence the time-honored practice of tying a flowering 
branch of a caprifig to the cultivated tree during the flowering season. 
3. Gall flowers, that is abortive pistillate flowers which do not develop 
seeds, but serve as a breeding place for the wasp, are instrumental in effect- 
ing caprification. They are found chiefly in the wild fig, and have short 
styles of such a length that the wasp is able to introduce its eggs into 
the ovary by means of its ovipositor. 4. Abortive flowers useless alike for 
the reproduction of the fig or of the wasp. In English they are known 
as mule flowers, and are the only ones present in numerous varieties, 
without perfect seeds. 

Two or even three crops of figs are produced by some varieties. The 
first crop ("Fichigrossi," " fiori," or "orni" figs) is borne early in the 
spring on the old wood. Later in the season " joniiti " figs are produced 



in the axils of the leaves on the lower portions of the new shoots, and 
"cratiri" figs on the upper portion. 

The ripe fig is not a true fruit but an aggregate of small fruits or drupe- 
lets in a fleshy receptacle. In this respect it is like a strawberry, but 
the fruitlets are borne on slender stems over the inner surface, not sessile 
in depressions over the outer surface of the receptacle. The numerous 
yellow, pear-shaped "seeds," about 2 mm. long, found in ripe figs, whether 
fresh or dried, are the seeds proper invested by the hard inner pericarp 
The fruit, strictly speaking, is a drupe. 


If fresh figs are not obtainable, the preserved fruit or even dried figs, 
soaked up in water, will answer for laboratory work. 

Receptacle. The fleshy receptacle forms the larger part of the fig. 

1. The Epidermal Cells (Fig. 299) are small, usually less than 20 ft 
in diameter, and have thick walls. Here and there they form rosettes, 
in the center of which are stout hairs (h) 
with globular bases up to 20 fi in diam- 
eter. Usually the hairs are short, some- 
times scarcely twice as long as broad, but 
occasionally they reach a length of 300 fi. 
In the dried fruit they are often detached, 
although the scars with rosettes of cells 
about them are always evident. 

2. Hypoderm. Several layers of small 
cells with thick walls underlie the epider- 
mis. They contain rosettes of calcium 

3. Fruit Flesh (Fig. 300). Proceeding 
inward, the cells increase in size but 
diminish in wall thickness, the bulk of the 
tissues consisting of loosely arranged, irreg- 
ular cells usually about 100 fi in diameter. 
Their content* are largely sugar, which in the dried fruit is crystalline. 
Branching but not anastomosing latex cells (m) ramify in great num- 
bers through the outer layers of the fruit flesh, also sparingly through 
the inner layers. They are remarkable for not only their numbers, but 
their size, reaching 50 /j. in breadth. The walls are delicate but distinct. 
Numerous minute granules which are colored intensely yellow bv iodine 

Fig. 299. Fig (FicusCarica). Epi- 
carp in surface view, h hairs and 
hair scars. X160. (Moeller.) 

388 FRUIT. 

solution are suspended in the milky contents. On warming, the latex 
coagulates, forming large drops. The fibro-vascular bundles occurring 
in the middle layer have small spiral or reticulated vessels usually only 
15 j« broad, seldom over 25 [i. 

4. The Inner Epidermis is of delicate-walled cells, which are not 



FlG. 300. Kg. Longitudinal section of fruit flesh showing p parenchyma, K crystals, m 
latex tubes and g vessels. X160. (Moeller.) 

easily found in the ripe fruit. Hairs occur on this as well as on the 
outer epidermis. 

Pericarp (Fig. 301). The inner surface of the receptacle is thickly 
beset with fruitlets inclosed by the perianth and borne on delicate stems. 
The perianth and stems are of thin-walled tissue of no special interest. 

1. The Epicarp Cells are thin-walled, more or less radially elongated. 

2. The Mesocarp of two or more layers is also of thin -walled, incon- 
spicuous elements. Tschirch and Oesterle have shown that in removing 
the so-called seeds (inner pericarp and seeds proper) the tissues separate 
through this layer, part of the cells adhering to the oufter layers, part 
to the inner. 

3. Outer Sclerenchyma (sc). This consists of exceedingly small stone 
cells 15 /x in diameter in a single layer. 

4. The Endocarp (st) or inner sclerenchyma is composed of one or 
more layers of rounded angular stone cells about 50 n in diameter. They 



have narrow lumen and thick walls with distinct rings and numerous 
branching pores. They are readily distinguished from the smaller cells 
of the outer sclerenchyma. 

Spermoderm (Fig. 302). The seed, which as a rule does not com- 
pletely fill the locule, is enveloped by a brown spermoderm, consisting of 
two or more layers of thin-walled, polygonal, isodiametric or somewhat 
elongated, often compressed cells (a, i). 

The Endosperm (Fig. 302, E) makes up about half the bulk of the 

Fig. 301. Fig. Elements of peri- 
carp (shell of nutlet) in surface 
view, sc outer sclerenchyma layer; 
st stone cells of endocarp. X 1 60. 

Fig. 302. Fig. Elements of seed in surface view. 
Spermoderm consists of a colorless outer epidermis 
and * brown inner layers; E endosperm; e embryo. 
X160. (Moeller.) 

seed. The cells are thick-walled, polygonal, about 50 n in diameter, 
and contain proteid matter and fat. 

The Embryo (Fig. 302, e) is curved so that cotyledons and radicle 
almost meet. Small thin-walled cells without marked characters make 
up the tissues. 


Preserves. Whole figs preserved in syrup or cordial are easily iden- 
tified by their form, taste and the numerous "seeds." If, however, they 
are cooked to a pulp the microscope should be brought into service. 
As the fig is one of the cheapest fruits in southern Europe, it, like the 
apple in America, is used as an adulterant of preserves purporting to 
be made from more valuable fruits. Marpmann has found tissues and 
seeds of the fig in numerous samples of strawberry, raspberry, and currant 

Fig Coffee, consisting of the dried, roasted, and ground figs, is a popular 
coffee substitute in various parts of Europe. It is adulterated with 
cereal products, legumes, chicory, and even, so it is stated, with foreign 

39° FRUIT. 

seeds; on the other hand, it may itself serve as an adulterant of genuine 

The microscopic identification of figs, whether in preserves or fig 
coffee, requires a knowledge of the tissues of both the receptacle and 
seed. The important elements are the outer epidermis of the recep- 
tacle with hairs (Fig. 299), the oxalate crystals of the hypoderm, the 
latex tubes (Fig. 300, m), often 30-50 p. broad (in chicory usually less 
than 10 / u), and finally the "seeds" (drupelets). The macroscopic appear- 
ance of the latter, also the peculiar manner in which they crush between 
the teeth, usually suffices for their identification, but in doubtful cases 
should be supplemented by an examination of surface preparations (Figs. 
301 and 302) and cross sections. The strawberry and fig nutlets are 
remarkably similar in macroscopic appearance, and a careful microscopic 
examination may be necessary in some cases to distinguish them. The 
crystal layer of the pericarp and the reticulated epidermis of the spermo- 
derm are characteristic tissues of the strawberry nutlet, with no counter- 
parts in the fig. 


See General Bibliography, pp. 671-674: Hanausek, T. F. (10, 16); Mace" (26); 
Moeller (29); Planchon et Collin (34); Schimper (37); Tschirch u. Oesterle (40); Vil- 
liers et Collin (42); Vogl (43, 45). 
Marpmann: Beitrage zur mikroskopischen Untersuchung der Fruchtmarmeladen. 

Ztschr. angew. Mikr. 1896, 2, 97. 
Nevinny: Zur Verfalschung des Feigenkaffees. Ztschr. Nahr.-Unters. Hyg. 1887, 1, 85. 


The date palm (Phcenix dactylifera L. order Palnuz) flourished in 
the gardens of the East long before the Christian era. At the present 
time it is cultivated in all the countries bordering on the Mediterranean, 
particularly in North Africa and Palestine, and also in Arabia and 
Persia, the fruit being the chief article of diet in -many regions. The 
Arabs of the desert depend on this tree for both food and shelter, and 
regard it with special veneration. 

Dates are of many varieties, differing in size (4-8 cm.), form, and 

The mesocarp is about 1 cm. thick and contains a high percentage 
of sugar. A hard endocarp like that of the cocoanut and oil palm is 
lacking; on the other hand, the seed (2-3 cm. long and 0.5 cm. broad) 

DATE. 39 l 

consists almost entirely of hard endosperm resembling that of the ivory- 
nut. On the dorsal side of the seed midway between the two ends, a 
rounded cavity contains the minute germ, while a groove extends the 
entire length of the ventral side. The spermoderm forms a thin brownish 
coat about the seed or stone. 


Pericarp. "Lacking fresh or alcoholic specimens, the dried dates of 
commerce may be soaked in water and finally hardened in alcohol. As 
noted by Braun, cross sections show five layers. 

i. The Epidermal Cells are of isodiametric form (10-30 /*) and color- 

2. The Hypoderm consists of two or more layers of cells (20-50 /*), 
with yellow or brown contents. 

3. Stone Cells, mostly radially elongated, form a layer of variable 

4. The Mesocarp Cells, proceeding from without inward, pass from 
tangentially elongated forms first into isodiametric and finally into radi- 
ally elongated forms. 

5. An Endocarp of colorless, longitudinally elongated, collapsed ele- 
ments forms a white silky-fibrous coat readily sep- 
arable from the stone. 

Spermoderm. Stones from dried dates are easily 
cut with a strong razor. 

1. The Epidermis (Fig. 303) is a single layer 
of narrow, elongated porous sclerenchyma elements, 
ranging in length up to 100 [i or more. On the 
middle of the dorsal side their longer diameters run 
parallel with the axis of the stone, but in other 
parts they are often transversely or diagonally ar- 
ranged. They also occur side by side in groups, 

5 ' \ 6 F» FlG . 303. Bate (Phoenix 

recalling the endocarp of the currant. dactylifera). Epider- 

2 . The Middle Layer (Fig. 304, g). All the &2j*E£K 
cells are tangentially elongated. Directly under the surface view. X160. 
epidermis, thick-walled porous elements occur here 

and there, but in the remaining two or more layers the cells are 
thin-walled, with side walls in interrupted contact, resembling the tube 
cells of cereals. These tube cells are often 20-30 ft wide and have 
brown contents. As a rule the outermost cells are extended in the same 



direction as the epidermal cells; those in the inner layer however are 
often at an angle. 

3. Inner Layers. One or two layers adjoining the endosperm are 
distinguished from the remainder, both in cross section and surface 
view, by their smaller dimensions and darker color. 

Endosperm (Fig. 305). The reserve material of the stone is largely 
in the form of thickened cell-wall, the structure of which closely resembles 
that of the ivory-nut. Although varying greatly in thickness, the double 
walls are, on the average, 15 /x and seldom exceed 30 fi. Conspicuous 
pores, broadest towards the middle lamella, add to the striking appear- 
ance of these cells. In the outer layers they are radially elongated, in 
the heart, isodiametric. Oil is the only visible cell-contents. 


The Fruit Flesh enters into many pastries, sweetmeats, and candies. 

The epidermis, hypoderm, and stone cells are readily found, but are 
not very characteristic. 

Date Stones are ground as a substitute or adulterant for coffee. Al- 
though both seeds have reserve material largely in the form of cellulose, 

Fig. 304. Date Stone. Parenchyma 
of spermoderm and g tube cells 
in surf ace view. X160. (Moeller.) 

Fig. 305. Date Stone. Endo- 
sperm with thickened cell walls. 
X160. (Moeller.) 

it is needless to say that date stones lack the valuable constituents of 

Sections should be cut for the identification of this material. The 
thick walls (Fig. 305) with distinct pores are readily distinguished from 
the knotty thickened walls of coffee. The double walls seldom or never 


exceed 30 ft in thickness, whereas in the ivory-nut they average 35 ft. 
Tissues of the spermoderm (Figs. 303 and 304) are radically unlike any 
in coffee, and quite different from those of the ivory-nut. 


See General Bibliography, pp. 671-674: Hanausek, T. F. (10, 16); Mace (26); 
Moeller (29); Planchon et Collin (34); Villiers et Collin (42); Vogl (45). 
Braun : Ueber das Vorkommen von Spharokrystallen aus Traubenzucker in den yer- 

schiedenen Drogen. Ztschr. allg. osterr. Apoth.-Ver. 1878, 16, 337. 
Hanausek, T. F.: Ueber die Anatomie der Dattelkerne. Chem. Ztg. 1886, 10, 701. 
Sachs: Zur Keimungsgeschichte der Dattel. Bot. Zeit. 1862. 
Zabuckie: Notes on the Structure of the Fruit Stone of the Date; Phoinix dactylijera 

L. Jour. N. Y. Micr. Soc. 1892, 8, 107. 


The banana tree (Musa sapientum L. order Musacea) is a native 
of the Old World, but is very extensively cultivated in tropical America. 
It is said to produce more food in a given area than any other plant. 
Throughout the tropics the banana is a staple article of diet in many 
regions, being of more importance than all other foods taken together. 
It is eaten either raw or cooked. ' Bunches of bananas are also shipped 
green in enormous quantities to Europe and the United States, where 
they are ripened in well-ventilated lofts. 

The elongated berry is either red or yellow, more or less angular, and 
varies in length from less than 10 to over 20 cm. It separates readily into 
a tough rind and a pulpy fruit flesh turning brown on exposure, the 
latter showing in cross section three indistinct locules with minute brown 
abortive seeds. The plantain (M. sapientum var. paradisiaca Hort.) 
has a larger fruit, which, like some varieties of the banana, is picked 
green and eaten cooked. 


A green banana will be found much easier to section than one fully 
ripe. Transverse, longitudinal, and tangential sections should be pre- 
pared, also mounts of the isolated fibers and abortive seeds. 

Pericarp. The rind, or so-called peel, containing most of the bundles, 
is easily stripped from the fruit pulp, the separation being through the 
delicate tissues of the outer mesocarp. 

1. The Epicarp Cells are small, polygonal, and thick- walled. Tan- 
gential sections show an indistinctly striated cuticle. 

394 FRUIT. 

2. Hypoderm. The cells of the outer layers of ground tissue are 
small, rather thick-walled, and closely arranged; but proceeding inward, 
the cells increase in size, the walls decrease in thickness, and the arrange- 
ment becomes more loose and spongy. T. F. Hanausek notes that some 
of the cells contain bundles of calcium oxalate raphides. The numerous 
bundles running through this ground tissue consist in the outer layers 
entirely of bast fibers, in the inner layers of the usual fibro-vascular ele- 
ments. Especially noticeable are the extraordinary size of the spiral 
vessels (often 50 p. in diameter) and their loosely wound spirals. Ac- 
companying each bundle are one or more chains of very conspicuous 
brown-walled, rounded, giant cells about 250 fi broad, resembling the 
oil-ducts of umbelliferous seeds. 

3. Mesocarp. The fruit flesh is a mass of rounded pulp cells which, 
in the outer layers, are nearly isodiametric, but in the inner layers are 
radially greatly elongated and readily separate as chains. Fibro-vas- 
cular bundles like those already described occur sparingly in the outer 
and also in the inner layers. The curiously shaped starch grains (Fig. 
306) are much elongated, mostly 20-40 n, occasionally 75 /* long, and 

Fig. 306. Banana Starch. X300. (Moeller.) 

have an excentric hilum, mostly in the broader end, and very distinct rings. 
Among the grains are fusiform, cigar-shaped, ovoid, rod-shaped, and 
other striking forms. Tschirch and Oesterle lay particular stress on the 
"sickle-shaped" forms, consisting of two curved grains united end tc 
end. The fleshy partitions contain numerous bundles accompanied by 
chains of brown giant cells like those in the hypoderm. E. Munrot 
Bailey has shown that the starch largely disappears during ripening 

4. Endocarp. The inner layer of the pericarp is made up of thin- 
walled cells mostly radially elongated. 

The Seeds are abortive, of a brown color, and lack distinctive elements. 



Dried Bananas are used whole as a confection and ground as a coffee 

Banana Flour. The ground dried pulp of the green fruit consists 
largely of starch and cellular debris. The starch grains, the broad, loosely 
wound spiral vessels and the chains of giant cells are characteristic. 

Guiana Arrowroot or Banana Starch. See p. 658. 


Hanausek, T. F.: Ueber Bananenmehl und seine mikroskopische Bestimmung. 

Ztschr. Unters. Nahr.-Genussm., 1910, 20, 215. 
Jahkel: Ueber Anatomie und Mikrochemie der Bananenfrucht und ihre Reifungs- 

erscheinungen. Diss. Kiel, 1909. 


The pineapple, one of the most delicious of tropical fruits, is the 
product of a herbaceous, endogenous plant (Ananassa saliva Schult. f., 
order Bromeliacece), a native of the West Indies and other regions of 
the New World. Like oranges and bananas, pineapples are now shipped 
to cooler regions in large quantities, but in Europe have not entirely 
supplanted the greenhouse product, which is said to have a finer flavor. 

The fruit consists of numerous fleshy berries, each with a single fleshy 
bract, united with an axis, forming a conical composite fruit shaped 
like a pine cone, hence the name pineapple. Surmounting the fruit is 
a tuft of sword-shaped saw-toothed leaves. The tapering, more or less 
appressed extremities of the bracts are toothed. The chartaceous, per- 
sistent perianth lobes form a close, dome-like structure covering a cavity 
in which are the remains of the styles and stamens. 


Bracts. 1. The Outer Epidermal Cells are small with wavy outline. 
The secondary walls are greatly thickened except for a spherical cavity 
scarcely one-third the diameter of the cell, which is entirely filled by a 
silicious body. 

2. Outer Hypoderm. One or more layers of very thick, sclerenchy- 
matized, porous-walled cells underlie the epidermis. Cross sections show 
that these cells are thicker than broad, and tangential sections, that they 
are somewhat elongated. 



3. Mesophyl. The hypodermal cells pass into a thin-walled but por- 
ous mesophyl, which, in the fleshy portions, is the same as the fruit flesh. 

4. Inner Hypoderm. Beneath the inner epidermis is a second layer 
of sclerenchyma elements. 

5. Inner Epidermis. This characteristic layer is composed of thin- 
walled, nearly square cells with sharply zigzag outline. They resemble 

somewhat the outer epidermal cells, but lack the 
silicious contents. 

Pericarp. No sharp distinction can be 
drawn between pericarp, perianth tube, and 
fleshy portion of bract, as they all unite to form 
the fruit flesh. 

1. An Epicarp is present only in the disc sur- 
rounding the style. The cells are much like 
those of the hypoderm of the bracts, but are 
more distinctly porous and consequently in tan- 
gential section appear beautifully beaded. 

2. Mesocarp. The cells of the fruit flesh are 
mostly isodiametric, and although thin- walled, 
are often distinctly porous. Beautiful raphides 
(Fig. 307), often over 100 p. long, occur in large 
numbers both singly and in bundles. The 
fibro-vascular bundles consist in large part of 

Fig. 307. Pineapple {Ana- ^zst fik ers with broad lumen and round pores, 

nassa saliva). Cross sec- 
tion of fruit flesh showing and broad spiral vessels often 25 fi in diameter. 

raphides. X160. (WintonJ ^ £w(W ^ The inner two Qr three layers 

are of tangentially elongated cells, those in the innermost layer, or endo- 
carp proper, being very narrow, usually only 10-20 ji broad. The walls 
are thin throughout. 


In preserves the chief elements are the cells of the parenchymatous 
fruit flesh, containing large raphides (Fig. 307), and the fibro-vascular 
bundles, consisting chiefly of bast fibers with broad lumen and round pores, 
also large spiral vessels. Occasionally one finds fragments of the bracts and 
other outer parts, of which the characteristic elements are: first, the small, 
square epidermal cells with zigzag walls and, in the case of the outer 
epidermis, with silicious contents; ar.d second, the thick- walled, some- 
what elongated, sclerenchyma elements. 



A number of the common vegetables are seeds and fruits picked while 
immature. The mature forms of some of these are described with the 
legumes (peas, bean, Lima bean), cereals (green corn), and spices 
(peppers) but identification of the vegetables by these descriptions is 
often difficult owing to the undeveloped condition of the tissues and 
starch grains. 

The vegetables here described include most of the fruits used 
minced or pulped in commercial products, such as pickles and catsups; 
the common roots and tubers used for culinary purposes, cattle feeding, 
starch manufacture and adulterating food products; and certain edible 

CUCURBIT FRUITS {Cucurbttacete.y 

The fleshy mesocarp of these fruits contains curious branching latex 
tubes. Thin-walled stomata occur in great numbers on the epicarp. 
The numerous flattened seeds are borne within the three large locules 
on three double-central placentas, but as these placentae extend to the 
outer wall before branching, thus forming false partitions, the seeds 
appear to be borne on parietal placentas. 

Several characteristic tissues are found in the seed, of which the thin- 
walled, ribbed palisade cells of the epidermis (Figs. 309 and 310, ep) and 
the sclerenchyma cells of the third layer (scl) are much alike in all the 
important economic species. 


See General Bibliography, pp. 671-674: Bohmer (6); Collin (8); Hanausek, 
T. F. (17); Harz (18); Planchon et Collin (34); Villiers et Collin (42). 
Barber: Comparative Histology of Fruits and Seeds of Certain Species of Cucur- 

bitacese. Bot. Gaz., 1909, 47, 263. 
Braemer: De la localisation des principes actifs des Cucurbitacees. Compt. rend. 

1893, 117, 753- 
Carles: Nouveau cas de fraude de conserves alimentaires. J. Pharm. chim., 

1885, 11, 547- 

1 The descriptions of cucurbit fruits are by Kate Barber Winton. 




Fickel: Anatomie u. Entwickelungsgesch. der Samenschalen einiger Cucurbitaceen. 
Bot. Ztg. 1876, 34, 737. 

Fischer: Ueber das Siebrohren System der Cucurbitaceen. Leipag, 1884. 

Godfrin: Etude histologique sur les tegument seminaux des Angiospermes. Soc. 
d. Sci. d. Nancy, 1880, 109. 

Hartwich: Semen Cucurbits. Arch, pharm. 1885. 

v. Hohnel: Morpholog. Untersuchungungen iiber die Samenschale der Cucurbi- 
taceen. Sitzungsber. Wiener Akad. 1876, 73. 

Kosutany: Die Kiirbiskernkuchen. Landw. Vers.-Stat. 1893, 43, 264. 


Wittmack, in his investigation of prehistoric remains in Peru, has 
secured evidence that the pumpkin {Cucurbita Pepo L.) is an American 
plant and not, as formerly believed, a native of the Old World. This 
belief is further substantiated by the statements of early explorers that 
the pumpkin was grown in maize fields by the aborigines just as is 
practiced to-day by American farmers. 

The pumpkin is the largest of all cultivated fruits, in extreme cases 
reaching the prodigious weight of nearly 100 kilos. It is apple-shaped, 

Fig. 308. Pumpkin (Cucurbita Pepo). Epicarpin 
surface view. X300. (Barber.) 

Fig. 308a. Pumpkin. Cross section 
of mesocarp showing am starch 
grains, and lot latex tube. X160. 

smooth, and of an orange or green-orange color. The fleshy rind, con- 
sisting of receptacle and pericarp, is several centimeters thick, and is 
highly esteemed in America for making pies as well as for feeding. About 
the seeds is a tangle of gelatinous, mesocarp fibers, such as occur in 
the melon and some other cucurbitaceous plants. Pumpkin seeds are 
1.5-2.5 cm. long, elliptical, strongly flattened, and have a narrow 
border on both sides. The embryo consists of two flattened cotyle- 
dons and a minute radicle. 




Receptacle and Pericarp, i. The Epicarp Cells (Fig. 308) are pris- 
matic, forming a palisade layer upward of 50 fi thick. In surface view 

FIG. 309. Pumpkin. Seed in cross section. 5 spermoderm consists of ep ribbed palisade 
cells of epidermis containing am starch grains, hy pitted subepidermal cells, scl scleren- 
chyma layer, m 1 pitted mesocarp cells, m 2 reticulated spongy parenchyma, p 1 parenchyma, 
p 2 spongy parenchyma, and p 3 inner epidermis; N perisperm; E endosperm consisting 
of aleurone cells; C cotyledon containing al aleurone grains. X160. (Barber.) 

they are for the most part polygonal and do not exceed 14 ft in diameter, 
but about the stomata they are somewhat elongated and curved. Their 
walls are bright yellow, whereas those of the stomata are colorless. 

40 o 


2. Hypoderm. Exceedingly small cells in several layers form the 

3. Mesocarp. The noteworthy elements of the fruit flesh are the 
strongly developed spiral vessels of the fibro-vascular bundles, often 60 ft 
broad, some with single strands and turns wide apart, others with 2-4 
strands and turns close together; also branching and anastomosing latex 
tubes (Fig. 308a, lat). The ground tissue is of large, rounded cells, 
containing starch grains up to 10 // in diameter {am). 

4. Endocarp. This is evident on the seeds as a thin membrane. 
Spermoderm (Figs. 309 and 310). Either fresh or dried seeds may 

Fig. 310. Pumpkin. Seed elements in surface view, ep ribbed palisade cells of epider- 
mis; ep 1 branching rib from epidermal cell; hy pitted subepidermal cells; scl scleren- 
chyma layer; m l pitted mesocarp cells; m 2 reticulated spongy parenchyma; p l paren- 
chyma; p 2 spongy parenchyma; p 3 inner epidermis of spermoderm; N perisperm; 
£ endosperm. X160. (Barber.) 

be used for making preparations, which should include transverse and 
tangential sections. 

1. The Palisade Epidermis (ep) is remarkable not only for the great 
height of the cells (often over 200 /x), but also for the longitudinal ribs 
with branches at the outer ends which strengthen the radial walls. In 
cross section these might easily be mistaken for the walls themselves, 
but in tangential section they are seen to be circular rods on a thin cell- 
wall. These cells contain small starch grains (am). 

2. Pitted Subepidermal Cells (hy). The small polygonal cells with 
numerous minute pores are arranged in 3-6 cell-layers. 

PUMPKIN. ' 401 

3. Sclerenchyma (scl). Cross sections of the cells are often oval, 
showing thick walls pierced by numerous pores. In surface view the 
cells are elongated with wavy outline, and are arranged end to end in 

4. Pitted Mesocarp Cells (m l ). These resemble the cells of the sub- 
epidermal coat, but form only one distinct layer. 

5. Reticulated Spongy Parenchyma (m 2 ). One or more layers of curi- 
ously reticulated cells with large intercellular spaces . form the most 
remarkable tissue of the seed. Their appearance is alike striking in 
cross section and surface view and reminds one of a prickly pear cactus. 

6. Parenchyma (p 1 ). The cells are large, of the usual type. 

7. Spongy Parenchyma (p 2 ). The parenchyma passes by degrees 
into a remarkable spongy tissue with a large ring evident, in surface 
view, in the center of nearly every cell. 

8. The Inner Epidermis (p 5 ). The cells resemble those of the pro- 
ceeding layer but are smaller. The protuberance in the center of each 
cell forming the ring seen in surface view is evident in cross section. 

Perisperm (N). This consists of a few layers of thin- walled cells 
more or less compressed. 

Endosperm (E). A single layer of well-defined aleurone cells forms 
the endosperm. 

Embryo (C). In sections examined in turpentine, we find numerous 
small aleurone grains 3-6 fi in diameter. 


Pumpkin Pulp is not only used for making pies, but also for adulterat- 
ing tomato catsup, jams, and other fruit products. 

The microscopic elements of the pulp of chief value in diagnosis, 
are the broad vessels, the latex tubes, the yellow epicarp (Fig. 308) with 
colorless stomata, and the reticulated spongy parenchyma of the seeds. 
These are best found in the coarser material obtained by straining through 
a sieve. 

Pumpkin-seed Cake is obtained in limited amount as a by-product 
in the manufacture of pumpkin-seed oil. The characteristic tissues of 
the spermoderm (Fig. 310) include the ribbed palisade epidermis (ep), 
the pitted parenchyma of the second layer (hy), the sclerenchyma cells 
with wavy outline (scl), and the reticulated spongy parenchyma (m 2 ). 




Fruits of numerous varieties of the winter squash (Cucurbita maxima 
Duch.) are put to the same uses as the pumpkin. They are widely dif- 
ferent in macroscopic characters, and according to Harz are somewhat 


— am 


Fig. 31012. Crook-necked Squash (Cucurbita Pepo var. verrucosa). Pericarp in cross sec- 
tion, epi epicarp with t hair and sto stoma; hy hypoderm; st outer mesocarp (stone- 
cell layer) with x spherical cavity; mes middle mesocarp with/» bundle and am starch 
grains. X160. (Barber.) 

different in histological structure. In the main, however, their structure 
corresponds closely with that of the pumpkin. 

Of the summer squashes the crook-necked (C. Pepo. var. verrucosa 
Naud.) and the turban squash (var. Melopepo L.) are the best known- 


The structure of the crook-neck squash (Fig. 3100) differs from that 
of the pumpkin chiefly in the persistence of jointed (i) and glandular 
hairs until maturity and the presence of a dense stone cell layer (st) in 
the outer mesocarp. The epidermal ribs of the seed branch along then- 
whole length, whereas in the pumpkin they branch only at the end. 


The cucumber or gherkin (Cucumis sativus L.) is a native of the 
East Indies, whence in ancient times its culture spread over various 
parts of Asia and Europe. 

The succulent fruit picked green is prized not only as a fresh vege- 
table eaten either raw or cooked, but also for pickling. 

Although variable in shape, it is usually elongated, in section rounded 
triangular, and has numerous warts on the surface, each capped by a 
short, blunt spine, which readily becomes detached on handling. The 
fleshy pericarp is green in the outer layers, but white further inward. 
Numerous flattened seeds are embedded in a gelatinous substance within 
the three locules. The cream-colored seeds are seldom over 2 mm. thick 
even when fully ripe, and are not, as in the case of the pumpkin seed, 
provided with a distinct border. 


Cucumbers, are often picked for pickling at such an early stage in 
their development that they do not show very marked differentiation 
of the tissues. When, however, they reach a diameter of 3 cm. or more, 
the structure both of the pericarp and seed is sufficiently characteristic 
to permit their identification with some degree of certainty. 

Pericarp (Fig. 311). A description of the full-grown fruit follows: 

1. Epicarp (epi). The cells are prismatic with thickened outer and 
radial walls. They reach the height of 75 fi or more and vary from 
7-20 fi in breadth. They do not contain chlorophyl grains. Stomata 
are absent. 

The warts have the same structure as the outer layers of the pericarp. 
Each bears an emergence (Fig. 311) consisting of large cells with thickened 
sparingly pitted walls. Attached to the apex of the emergence is a broad,, 
jointed (up to 10 cells) conical hair (/). The cross walls and the inner 
wall of the sunken foot cell are not only thickened but pitted. Occasionally 
a second hair, similar in structure but smaller, develops at the side of 



the terminal one. The hairs usually disappear in the early stages of 
growth, but the emergence, unless rubbed off, persists as a hyaline spine. 

Fig. 311. Cucumber (Cucumis sativus). Pericarp in 
cross section, epi epicarp with emergence bearing 
t hair; hy hypoderm; st sclerenchyma cells at 
base of emergence, X55. (Barber.) 

Fig. 3 1 10. Cucumber. Seed in cross 
section. 5 spermoderm consists 
of ep epidermis, sub subepidermal 
layer, scl, sclerenchyma, p l stel- 
late parenchyma, p 2 spongy par- 
enchyma; N perisperm; E en- 
dosperm; C cotyledon consists 
of ep epidermis and mesophyl 
with al aleurone grains. X160. 

Fig. 311&. Cucumber. Isolated subepidermal cell Fig. 311c. Cucumber. One-half of 
of spermoderm in surface view. X300. (Bar- isolated cell of sclerenchyma layer 

ber.) in surface view. X300. (Barber.) 

In addition to the wart hairs, numerous, small capitate hairs, with- 
a four-celled head and jointed stalk, cover the immature fruit, but dis- 
appear early, leaving no scars. 


2. Hypoderm (hy). During the growing stages the several layers of 
small, rounded cells contain numerous chlorophyl grains, to which the 
fruit owes its green color. Beneath each emergence is a group of pitted 
sclerenchyma cells (st). 

3. The Mesocarp, or fruit flesh, is a mass of loose parenchyma, with 
isolated sieve tubes, latex tubes, and fibro-vascular bundles. 

The Spermoderm (Fig. 311a) is best studied in seeds taken directly 
from a ripe cucumber, as those obtained from a seedsman often lack 
the outer epidermis. 

1. The Palisade Epidermis (ep) is thickened by broad, tongue-like 
sclerenchymatized rods. The prismatic cells reach a height of 160 n 
on the sides of the seed and over 250 ji at the edge. 

2. Subepidermal Layer (sub). These cells have thick porous walls 
and are arranged end to end in rows. Numerous small intercellular 
spaces are evident in surface view (Fig. 3 116). The layer reminds us of 
the epidermis of oat chaff, except that only elongated cells are present. 

3. Sclerenchyma (scl). In surface view this layer is very striking 
even in green cucumbers, owing to the branching, sclerenchymatized 
cell-walls (Fig. 311c)- 

4. Spongy- Parenchyma. In the outer layers (Fig. 311a, p l ) the cells 
are star-shaped, in the inner layers typical spongy parenchyma (p 2 ) . 

The Perisperm, Endosperm, and Embryo lack distinctive features. 


Not only whole cucumbers, but quite small pieces are recognized 
by the warts on the surface, the thin elliptical seeds, and other macro- 
scopic characters. 

The microscopic elements of value in diagnosis are the palisade ■ 
epidermal layers of both the fruit and the seed, the emergences with scler- 
enchymatized cells at the base, and the sclerenchyma layer of the seed. 


The muskmelon (Cucumis Melo L.) is a native of southern Asia and 
tropical Africa. 

The hollow fruit is spherical or slightly elongated with 8-12 narrow 
longitudinal grooves. The surface is yellow-green with brown reticulations. 

40 6 



Pericarp (Figs. 311^ and sue). 1. Epicarp (epi). On the ribs the 
cells are very thick-walled with a flask-shaped lumen and a thick cuticle. 
The reticulations are of cork tissues (su) which break through the epi- 
carp similar to lenticels. In the grooves the epidermal cells have thinner 
walls. Curious stomata (sto) and jointed hairs (t) are present. 

2. Hypoderm (hy). Moderately thick-walled pitted cells form this 

Fig. 3iid. Muskmelon (Cucumis Melo). Pericarp in surface view, epi epicarp with t 
hair and sto stoma; Ay hypoderm. X160. (Barber.) 

3. Mesocarp (mes). Bundles and latex tubes are scattered through 
a mass of loose parenchyma. 

Spermoderm (Fig. 311^). 1. The Palisade Epidermis (ep) is strength- 
ened by slender rods without evident branches. 

2. Subepidermal Layer (sub). Pitted cells with thickened walls form 
several layers. 

3. SclerencKyma (scl). The cells are large with thick branching walls 
resembling those of the cucumber. Fig. 311^ shows how the cells fit 

4. Spongy Parenchyma (p 1 , p 2 ) . This consists of 4-5 layers of slightly 
thickened porous cells intermediate in characters between the corre- 
sponding cells of the pumpkin and the cucumber. 

Perisperm, Endosperm, and Embryo are like those of the cucumber. 


The watermelon (Citrullus vulgaris Schrad.) comes to us from Africa, 
where it is eaten by the natives and the larger animals. 





Fig. 3iie. Muskmelon. Rib of pericarp in cross section, epi epicarp; su cork; hy 
hypoderm; mes mesocarp. X50. (Barber.) 

Fig. 311/. Muskmelon. Epicarp in 
tangential section. X160. (Bar- 

Fig. 3 1 ih. Muskmelon. Isolated scleren- 
chyma cells of spermoderm. X300. 
1 -I.) 


Fig. 3iig. Muskmelon. Seed in cross sec- 
tion. _ 5 spermoderm consists of ep epi- 
dermis, sub subepidermal layer, scl scler- 
enchyma, p 1 sclerenchymatized spongy 
parenchyma, p 2 spongy parenchyma; 
N perisperm; E endosperm; C cotyle- 
don with ep epidermis and mesophyl 
containing al aleurone grains. X160. 



The large fruit is ellipsoidal with a dark-green surface, often mottled 
with light green. The rind or outer portion of the fruit flesh is white 
or light green, of firm texture; the inner portion is red, pink or yellow 


FlG. 312. Watermelon (Citrullus vulgaris). Pericarp in cross section, ept epicarp with 
sto stoma; hy hypoderm; st outer mesocarp (stone-cell layer); x parenchyma between 
groups of 'stone cells; mes middle mesocarp. X160. (Barber.) 

Fig. 3120. Watermelon. Pericarp in surface view. Epicarp with sto stoma; hy hypo- 
derm. X 160. (Barber.) 

of looser texture, with numerous bundle fibers. Embedded in the inner 
pericarp are the black or light-brown, flat, lustrous seeds. 

Pericarp (Figs. 312, and 312a). 1. Tlie Epicarp (epi) consists of 
cells with thickened outer and radial walls and stomata with thin-walled 
accompanying cells. 



2. Hypoderm (hy). This is made up of 10-12 layers of indistinctly 
pitted cells. 

3. Stone Cells (st) in one or more layers form a distinct zone in the 
mature fruit. During the earlier stages of development these stone cells 
occur in groups, but later the groups become almost continuous. 

Fig. 3125. Watermelon. Seed in cross-section. 5 spermoderm consists of ep epidermis, 
sub subepidermal layer, scl sclerenchyma, p 1 sclerenchymatized parenchyma, p 1 inner 
parenchyma; JV perisperm; E endosperm; C cotyledon with ep epidermis and ai 
aleurone cells. X160. (Barber.) 

4. Mesocarp (mes). This tissue consists of parenchyma cells with 
moderately thick, porous walls and intercellular spaces; among these 
ramify bundles and latex tubes. 

Spermoderm (Fig. 3126). 1. The Epidermis (ep) consists of pris- 
matic cells strengthened by slender, often forked rods. 


2. Subepidermal Layer (sub). A broad band, several cells thick, 
consists of pitted cells of various sizes and shapes. 

3. Sclerenchyma (scl). Unlike the other economic cucurbitaceous 
seeds, the cells are nearly isodiametric and irregularly arranged. 

4. Spongy Parenchyma, and 5. Inner Epidermis complete the sper- 

Perisperm, Endosperm, and Embryo are similar to the corresponding 
layers of the cucumber and the muskmelon. 


This family yields a number of important products, of which the 
potato (p. 414) is a tuber, the eggplant and tomato are fleshy fruits, and the 
garden peppers are dry fruits. Cayenne pepper and paprika, the latter 
being but a variety of our garden peppers, are described under spices 
(p. 515). The structure of the tomato is of special interest because of 
the adulteration of tomato products. 


There is good evidence that the tomato (Solatium Lycopersicum L., 
Lycopersicum esculentum Mill.) was cultivated in Peru long before the 
discovery of America.. A plant believed to be the original form of the 
species grows wild in Peru, also on the Pacific coast of Mexico and Cali- 
fornia. Numerous varieties are now grown as garden vegetables through- 
out the civilized world, except in the coldest regions. 

The fleshy fruit varies in the different varieties from the size of a 
currant to the size of a cocoanut. Its color is red, pink, or yellow, accord- 
ing to the color of the fruit flesh; the smooth, lustrous skin, however, is 
bright yellow in all the varieties. Normally the fruit is bilocular, but 
as a result of cultivation is multilocular. Numerous seeds (Fig. 313) 3-4 
mm. long, inclosed in a gelatinous mantle, partly fill the locules. Freed 
from this substance they are dull yellow, ovoid, flattened, 3-4 mm. long 
and thickly beset with short, silky hairs. The spirally coiled embryo 
with elongated radicle and cotyledons, each about 3 mm. long, is em- 
bedded in the endosperm. 


The ripe fruit should be hardened in alcohol before cutting sections. 
The skin is separated by plunging the fruit for a moment in boiling 



water. Soaking the seeds in a very dilute alkali facilitates the removal 
of the gelatinous material, after which they may be held between pieces 
of pith and sectioned. 

Pericarp. The skin which separates from the fruit 
flesh consists of epidermis and hypoderm, the walls 
of both being characterized by their golden yellow 

1. Epicarp (Fig. 314, epi). The cells, as seen in 
surface view, are polygonal, 16-35 f- m diameter. 
Their yellow radial walls are thick, 6-8 /£, and dis- 
tinctly beaded. At the corners they are often collenchy- 
matously thickened. 

2. The Hypoderm (Fig. 314, hy) consists of a 
single layer of cells larger than those of the epicarp, FlG 3I3 Tomato 
but like the latter with thick, yellow, porous walls. {Solanum Lycopersi- 

J cum). Seed in cross 

3. Mesocarp. The rounded pulp cells of the ground section. (Moel- 
tissue have no distinctive characters. The vascular LER- ' 
elements of most of the bundles are spiral vessels, seldom over 20 fi in 
diameter, but those in the strongly developed bundles near the stem 

Fig. 314. Tomato, epi epicarp and hy hypoderm of pericarp (skin), X300; ep outer 
epidermis of spermoderm with I ribs, from below. X 1 60. (Winton.) 

are partly pitted vessels. Bast fibers accompany these latter bundles, 
but are lacking elsewhere. 

4. Endocarp. This layer is of thin-walled, polygonal elements hardly 
distinguishable from the pulp cells. 

Spermoderm (Fig. 314; Fig. 315, S). 1. The Outer Epidermis (ep) 
is highly characteristic owing to the pronounced ribs (t) on the delicate 
radial walls, the latter being evident only under the most favorable con- 
ditions. These ribs have hitherto been mistaken for hairs. They vary 



up to over 500 p. in length. Seen from below the inner walls of the 
epidermis are sinuous and strongly thickened. 

2. The Middle Layers consist of several layers of small, brown, oblit- 
erated cells, which in the ripe seed do not 
assume their original form even after treatment 
with reagents. 

The Perisperm (Fig. 315, N), after treat- 
ment of cross sections with Javelle water, is 
seen to consist of a distinct layer of thin-walled 

Endosperm (Fig. 315, E). The cells have 
rather thick, rigid walls. They contain minute, 
rounded aleurone grains seldom over 6 p in 
diameter, and fat. 

The Embryo consists of typical embryonic 
tissues with contents the same as those of the 

Whole Tomato Products. Under this head 
are included canned tomatoes, tomato pre- 
serves, and other preparations of the whole 
fruit, from which the skin has been removed 
by scalding. The chief microscopic elements 

Fig. 315. Tomato. Seed in are rounded pulp cells, vascular elements 
cross section. 5 spermoderm . . , , 

consists of / epidermal ribs, (chiefly small spiral vessels) and seeds with 

N perisperm; E endosperm " hair-like epidermal ribs (Figs. 314 

also layers of compressed cells; i-i. 

N perisperm; E endosperm 

and Ra radicle, both contain- and 3 1 5, t). Fragments of the skin with 

(Winton. 1 ) 116 grainS ' * °' golden yellow porous cells of the epicarp (Fig. 

314, epi) and hypoderm (hy) are frequently 

present in small amount as an accidental impurity, even in products 

made from the pared fruit. The adulterants are dyes, preservatives, 

foreign pulp and, in the case of preserves, agar-agar, starch-paste, and 

other gelatinous materials. 

Tomato Catsup, or Ketchup, a popular sauce in the United States, is 

manufactured in enormous quantities, and sold in bottles. Properly 

made it consists of a mixture of tomato pulp, freed from seeds, with 

sugar, vinegar and spices; but much of the catsup on the market is made 

from decomposed tomatoes artificially colored, and preserved with sodium 

TOMATO. 413 

benzoate. Adulteration with pumpkin and apple pulp and possibly 
with other foreign pulps, is also practiced. The coal-tar dyes usually 
employed in tomato products do not remain in solution, but are taken 
up by the protoplasmic contents of the cells, which ordinarily have little 
or no color. Their detection is best effected by Arata's wool test l and 
other chemical methods. Preliminary to the usual chemical tests for 
salicylic and benzoic acids, Lagerheim's sublimination test (p. 320) should 
be employed. 

For the detection of foreign pulps it is advisable to examine the coarser 
material, consisting of seeds, fragments of skin, and vascular elements, 
obtained by washing on a sieve with 1 mm. mesh in a stream of water. 
The vessels of the pumpkin are larger than those of the tomato; the 
yellow epicarp cells (Fig. 308) are smaller (14 p), non-porous and are 
interspersed with colorless stomata. The branched and jointed latex 
cells of the mesocarp occur in considerable numbers, but require care 
in identification. Of the greatest value, although of less frequent occur- 
rence, are the reticulated spongy parenchyma cells of the mesocarp. The 
carrot (Fig. 322) is characterized: (1) by the elongated epidermal cells; 
(2) by the polygonal cells of the cortical parenchyma containing chro- 
moplasts; and (3) by the elements of the bundles, of which the rather 
large'' vessels (Often 50 fi broad) with closely crowded reticulations, are 
quite different from the vessels of the tomato. The vessels of the beet 
(Fig. 321) are mostly 50 /j. broad (sometimes 50-100//), with very large 
and open reticulations. A noteworthy peculiarity of the reticulated 
vessels of the turnip (Fig. 323), are their short joints, often broader than 
long. The meshes are smaller than those of beet vessels. 


See General Bibliography, pp. 671-674: Mace" (26); Villiers et Collin (42). 
Beiosi e Gigli: Intorno alia struttura anatomica ed alia composizione chimica del 

frutto del Pomodoro (Lycopersicum esculentum Mill.). Rendic. delle sess. della 

R. Acad, delle scienze dell'Ist. di Bologna. 1889, 59. 
Carles: Nouveau cas de fraude de conserves alimentaires. Journ. pharm. chim. 

1885, 11, 547. 
Hockauf: Ueber bisher wenig berucksichtigte Merkmale der Solanaceen-Samen. 

Ph. Centralh. 1905. 
Marpmann: - Beitrage zur mikroskopischen Untersuchung der Fruchtmarmeladen 

Ztschr. angew. Mikr. 1896, 2, 97. 

'Ztschr. anal. chem. 1889, 28, 639; Jour. Am. Chem. Soc. 1900, 22, 582. 




Of the vegetables produced underground some are tubers (potato, 
artichoke), others, true roots (beet, carrot, turnip, sweet potato), and 
others still, bulbs (onion). Those here described include some that are 
used minced or pulped in food products. 

The potato and the beet are not only important vegetables, but the 
former is a raw material for the manufacture of starch and alcohol, and 
the latter is the source of a large part of the world's supply of sugar. 

The potato and sweet potato are identified by the starch grains; 
the beet, carrot, and turnip by the vessels. 


The potato (Solanum tuberosum L. order Solanacem), a native of 
South America, was introduced into Europe in 1560-1570, and was 

Fig. 316. Potato {Solanum tuberosum). Fig. 317. Potato. Cork tissue in surface 
Cross section of tuber showing cork view. X160. (Moeller.) 

cells and starch parenchyma. X160. 

first cultivated on a considerable scale in Italy and Holland. For the 

past hundred years it has been one of the most valuable of cultivated 

plants throughout the temperate zone, the tubers serving as a vegetable- 

1 The descriptions of tubers and roots are by Prof. J. Moeller. 


and for the manufacture of starch, glucose and alcohol. The tubers 
differ in form and size, also in the texture, color and flavor of the flesh. 
They bear numerous "eyes" or buds in depressions on the surface. 


Cork. The protective coat on the surface is a cork tissue (Fig. 316), 
with large cells, which in surface view are polygonal (Fig. 317). 

Parenchyma. The outer layers are tangentially elongated, and con- 
tain proteid matter in the form of small aleurone grains. Further in- 
ward the cells are large, isodiametric, with intercellular spaces. They 
are filled with starch grains, most of which are large, irregularly pear- 
shaped, with distinct rings and an excentric hilum located in the small 
end (See p. 659). 


The starch grains (Fig. 581) are highly characteristic. 

See General Bibliography, pp. 671-674: Moeller (29); Planchon et Collin (34). 


Under this name are known the tubers of an Asiatic plant (Stachys 
Sieboldii Miq., order Labiatiz). They are 2-5 cm. long, 1 cm. thick, 

Fig. 318. Japanese Potato (Stachys Sieboldii). Epidermis of tuber in surface view. 


and are divided into joints by constrictions, in each of which are two 
opposite membranaceous leaves. 



The Epidermis (Fig. 318) consists of irregularly polygonal cells and 
a few stomata. 

Between the Fibro-vascular Bundles are numerous small sieve tubes. 

The Parenchyma of the flesh consists of unusually small cells, con- 
taining a soluble carbohydrate, stachyose. In tubers dug in the spring, 
starch is present. 


The tubers of Helianthus tuberosus L. (order Composilce), a North 
American plant, are of some importance as food for both man and cattle. 
They are red-brown, elongated, often pear-shaped, and bear small roots, 
warty sprouts, and transverse rings. The flesh is white or red. 


The bark is scarcely 1 mm. thick. 

1. The Epidermis (Fig. 319), which is easily removed, consists of 
large, polygonal, slightly thickened cells, and here and there cork tissue 
with large cells. 

2. Cortex (Fig. 319). The cells are quadrilateral, and often trans- 

Fig. 319. Jerusalem Artichoke {Helianthus tuberosus). Epidermis and one of the pareu 
chyma layers of tuber in surface view. (Moeller.) 

versely elongated. Some of them have somewhat thickened, scleren* 
chymatized walls. 

3. The Bast contains balsam ducts, but no bast fibers. 

4. Xylem. Within the indistinct cambium are irregular groups of 
vessels, often in radial rows. The cavity is narrow; the walls have thick 



reticulations. Large, rather thick-walled cells containing inulin con- 
stitute the medullary rays. 


The balsam tubes, the quadrilateral stone cells of the cortex and the 
narrow reticulated vessels serve for identification. 


The roots of the common beet (Beta vulgaris L., order Chenopodiacea), 
and particularly the exhausted residue from the beet-sugar factories, are 
used both as cattle foods and as adulterants of chicory. 


The Cork (Fig. 320) forms a thin outer zone of large cells with thick 
walls. By far the 
larger part of the root 
consists of Parenchyma 
(Fig. 321, p), the cells 
of which are about 
2 50 fi in diameter, with 
walls 5 fj. thick. T. F. 
Hanausek finds the 
presence of crystal 
sand cells the only prac- 
ticable means of dis- 
tinction from chicory. 

Fig. 320. Beet (Beta vuU Fig. 321. Beet. Longitudinal section of root, p paren- 

garis). Cork layers of root chyma; g reticulated vessels; I bast fibers. X160. 

in surface view. X160. (Moeller.) 


The Vessels (Fig. 321, g) are mostly 50 /*, occasionally up to 100 p t 
the reticulations forming broad meshes. 


See General Bibliography, pp. 671-674: Hanausek, T. F. (16); Mace 1 (26); 
Moeller (29); Planchon et Collin (34); Vogl (45, 48). 


Occasionally the carrot (Daucus Carota L., order Umbellijercs) is em- 
ployed as an adulterant of chicory. 

The Cork and Parenchyma are similar to those of the beet, but the 

Fig. 322. Carrot {Daucus Carota). Longitudinal section of root showing parenchyma 
and reticulated vessels. X160. (Moeller.) 

parenchyma consists of smaller cells, which contain yellow chromoplasts 
suspended in the cell sap. 

The Vessels (Fig. 322, g) are seldom over 50 /i broad, and are charac- 


terized by their narrow elongated pores, resembling those in the vessels 
of the dandelion root. 

See Bibliography of Beet. 


The white turnip {Brassica Rapa L., order Crucijerce) serves as a 
food for man and beast, also as an adulterant of coffee, horseradish, etc. 


The cork is similar to that of the beet, but the cells are smaller. More 
characteristic are the cells of the Parenchyma (Fig. 323, p), which are 

i^S 9 , 

Fig. 323. White Turnip (Brassica Rapa). Longitudinal section of root, p parenchyma; 
g reticulated vessels; a starch grains. X 160. (Moeller.) 

exceptionally large (commonly 500 ft) and thin-walled (2 fi). They con- 
tain small aleurone grains, and here and there crystal sand (calcium 

The Vessels (g) consist of short joints, and have narrow, rounded 
pores resembling those of chicory. 

See Bibliography of Beet. 


Edible fungi when whole and fresh may usually be distinguished by 
their gross appearance. Only in the examination of the dried material 

1 The descriptions of the individual fungi are by Prop. J. Moellek. 


or food products containing sliced or minced fungi is the microscope 

The common species found on the market belong in the following 
subclasses and orders : 

Ascomycetes: Spores produced within sacs (asci.) 

i. Discomycetes : Asci borne on the outer surface of various 

shaped fructifications (e.g., Morel). 
2. Tuberaceae: Asci borne within a tuberous fructification (e.g., 
Basidiomycetes: Spores produced on the surface of sacs (basidia). 
i. Hymenomycetes : Basidia borne within the (usually umbrella- 
shaped) fructification on gills (e.g., common mushroom), rods 
(e.g., Boletus), etc. 
2. Gasteromycetes : Basidia borne within the (often tuber-shaped) 
fructification (e.g. puff-balls). 
The descriptions which follow are designed merely to aid in detect- 
ing adulteration and not to distinguish edible from poisonous species. 


Fungi belonging to the order Tuber acea of the Ascomycetes develop 
underground tuberous fructifications known as truffles. These bodies 
are black or dark brown, with pyramidal or shield-shaped, polygonal 
warts. Cross sections show cavities or channels lined with masses of 
hypha? tissues (hymenium), in which are borne club-shaped elements 
(asci), each containing 1-4 (seldom more) unicellular spores (Fig. 325). 
The size, form, color and markings of the spores furnish the best means 
for identification of the species. They are obtained for study either by 
cutting sections of the inner tissues, or by scraping the inner surface. The 
following are the common species. 

1. French or Perigord Truffles {Tuber brumale Vitt.) because of their 
fine flavor are the most highly prized of the group. They grow mostly 
under oaks in France, Northern Italy, and Southern Germany. The fruit 
bodies vary from the size of a hazelnut to that of an apple. On the 
surface they are black, with well-defined warts ; within they are dark 
violet or red-black. The spores are coffee-brown, elliptical, 25-45 n 
long, thickly beset with prickles (Fig. 326, d). The true perigord truffle 
(var. Melanospermum) has dark, very aromatic flesh, and almost black, 
often large spores (Fig. 326, c). 


2. German or Hanover Truffles {Tuber astivum Vitt, also var. mesen- 
tericum and uncinatum) are less aromatic than the preceding. They are 

Fig* 324. German Truffles (Tuber (estivum). Vertical section showing rind, air passages 
dark veins of compressed hyphae, and masses of asci. Natural size. (Tttlasne.) 

obtained from Northern Italy, France, Germany, Switzerland, and 
Bohemia. The flesh is lighter than that of French truffles, and the 

Fig. 325. French Truffles {Tuber brumale). Section showing hyphae and spore-bearing 

asci. X400. (Tulasne.) 

yellow or coffee-brown spores (Fig. 326, a, b) are characterized by then- 
broad reticulations. 


Whole truffles cannot be successfully adulterated, but in the dried 
condition other fungi are often substituted. Truffled pate's frequently 
contain these substitutes. They are detected by their color and the 
characters of the spores, although it is difficult or impossible to determine 
the exact species. 



The following are the common substitutes: 

i. White Truffles (Choiromyces maeandrijormis Vitt.) are found in 
^England and middle Europe. They are light yellow-brown, and re- 
semble potatoes in external appearance. The flesh is white to brown, 
with brown veins, and is but slightly aromatic. The small (15-20 fi) 
globular spores are light brown, beset with numerous prickles of unequal 
length (Fig. 326, e). 

2. False Truffles (Scleroderma vulgare Hornem. — Gasteromycetes) are 
aerial, tuberous bodies about the size of genuine truffles, with a 
skin 2-3 mm. thick. Within, the tissues are at first white, later gray to 

Fig. 326. Spores of Truffles and Substitutes, a and b German Truffles; c and d French 
truffles; e white truffles; / false truffles {Scleroderma); g false truffles (Khizopogoti). 


black. The small spores are globular, black, with prickly warts (Fig. 
326,/). They can only be used green, in which state they have a dis- 
agreeable flavor quite unlike that of real truffles. 

3. Species of Rhizopogon (Gasteromycetes) develop under ground 
tuberous bodies, externally similar to those of Scleroderma. They have 
a membranous or leathery periderm difficultly separable from the 
flesh, and very small, ellipsoidal, smooth, almost colorless spores (Fig. 

3 26 > g)- 

4. Species of Elaphomyces are closely related to real truffles. Their 
fruit bodies develop underground, and on ripening are converted into a 
powdery mass. They are not edible. 




The morels belong to the order Discomycetes, of the sublcass Ascomy 
cetes. The fleshy, club-shaped or globular head is borne on a stalk 
The hymenium (Fig. 327) covers the reticulated outer 
surface of the head, and consists of a palisade-like 
layer of asci and paraphyses, each of the former con- 
taining eight smooth, mostly ellipsoidal spores. 

The following species are of importance : 

1. The Common Morel (Morchella esculenta Pers.) 
has a hollow stalk, yellow to brown head, and ochre- 
colored spores. 

2. The Spring Morel (Gyromitra esculenta Ft.) has 
a hollow stalk, hollow or collapsed coffee-brown head, 
and white spores. 

3. The Autumn Morel (Helvella Infula Schaffer) 
has a thin brown head united only in the middle with 
the stalk, and white spores. 

All the species are edible, although the spring 
morel and some others must be first treated with 
hot water to remove a poisonous principle, which 
also disappears slowly on drying. 

Fig. 327. Common 
Morel (Morchella 
esculenta). Cross 
section through 
hymenium, show- 
ing asci and para- 
physes. (Mez.) 


These are umbrella-shaped, and bear the hymenium on the under 
surface of the head. They belong to the order Hymenomycetes of the 
subclass Basidiomy cetes. 

1. The Field Mushroom (Psalliota campestris Fr., Agaricus cam- 
pestris—AgaricinecB) has when young a globular head, which later becomes 
spreading, reaching 15 cm. in breadth. The upper surface is brownish; 
the flesh is white. On the under surface are numerous spore-bearing 
gills, which are at first pink, but later are brown, as are also the elliptical 
spores (8 : 6 p) . The stalk is white, 6-8 cm. long, with a thick mem- 
branous ring (volva) near the center. 

Cross sections through the lamellae show in the middle a layer of 
broad hyphae (Fig. 329), flanked on both sides by small hyphae from 
which spring the basidia; also the sterile bodies known as paraphyses. 
The spores are borne on the surface of the basidia. 

The poisonous Amanita phalloides Quel (A. bulbosa Bull.) has a 



bulbous thickening at the base of the stalk, bordered by a sac-like mem- 
brane, also white spores. Cross sections of the lamellae show that the 

Fig 328. Field Mushroom (Psalliota (Agaricus) campestris). 1 Natural size, showing 
I lamellae 2 Cross section of a lamella, magnified. (Sachs.) 

Fig. 329. Field Mushroom. Cross, section of a lamella, strongly magnified. (Mez.) 

Fig. 330. Poisonous Amanita (-4. phalloides). Cross section of a lamella. (Mez.) 

middle - hypliEe layer is surrounded by hyphae spreading out in bows 
(Fig. 330). 


2. Boletus edulis Bul\.(B.bulbosus Schaff. — Polyporea) and other edible 
species of Boletus, are distinguished from the species of the AgaricinecB 
by the thick swollen stalk, and the dependent tubes on the under surface 
of the head. The brown head is at first semiglobular, later spreading, 
reaching 20 cm. Its flesh is white, and does not greatly change in color 
on exposure. The tube layer, which is easily removed from the under 
side of the head, is at first white, later yellow or green-yellow. The 
spores are spindle-shaped, smooth, yellow or brown. 




Savage and civilized nations alike are addicted to the use of alka- 
loidal as well as alcoholic stimulants. The American aborigines long before 
the discovery of the continent by Columbus were acquainted with the 
virtues of the cocoa bean and the tobacco leaf, and the natives of West 
Africa have for centuries chewed the cola nut. The products here 
described include those containing caffein, theobromin and nicotine, also 
certain substitutes free from alkaloids. Opium and other more potent 
alkaloidal products are considered in works on pharmacognosy. 


Coffee, next to sugar the most important product imported from 
the tropics, is the seed of a small tree or shrub, Cofjea Arabica L. (order 
Rubiacea), a native of Abyssinia and other parts of Africa. In the fifteenth 
century the tree was introduced into Arabia, where the beverage became 
popular with all classes, notwithstanding the opposition of the Moham- 
medan priests. Coffee drinking was soon taken up by all the Saracenic 
races and later by the European nations. 

For over two hundred years the culture of the coffee tree was limited 
to Arabia, but in the latter part of the seventeenth century it was suc- 
cessfully undertaken by the Dutch in Java, and somewhat later in Surinam, 
and the industry soon spread over Sumatra, India, Ceylon, Western 
Africa, and other parts of the Eastern Hemisphere, as well as over the 
West Indies and the tropical parts of South America. To-day Brazil 
leads the world in coffee production, although the choicest grades come 
from Arabia (genuine Mocha coffee) and Java. 

The white and delightfully fragrant flowers of the coffee tree are 
produced in the axils of the leaves. The fruit (Fig. 331) is about the 
size of a small cherry, and is red or purple when fully ripe. It normally 

1 The descriptions of tea, tobacco, and all other leaves, also of chicory, dandelion, 
guarana, and cola nut are by Prof. J. Moeller. 




contains two cells, each with a single plano-convex seed (Figs. 331 and 
332) so situated that the flat surfaces of the two seeds adjoin one another, 


, Em 

Fig. 331. Coffee (Coftea Arabicd). I cross section of berry, natural size. Pk outer peri- 
carp; Mk endocarp; Ek spermoderm; Sa hard endosperm; Sp soft endosperm. II 
longitudinal section of berry, natural size; Dis bordered disc; Se remains of sepals; 
Em embryo. Ill embryo, enlarged: cot cotyledon; rod radicle. (Tschirch and 

but in the so-called peaberry coffee, one of the ovules is abortive, the other 
developing into a rounded seed filling the single cavity. The outer portion 
of the fruit is dark colored and pulpy, lined by a buff, parchment-like 
endocarp. The seeds, which before roasting are yellow or light green, 
have a longitudinal cleft on the flattened side due 
to the folding of the endosperm. A papery spermo- 
derm, known as the silver skin, covers not only 
the outer surface but penetrates also the cleft. 
The minute embryo (Fig. 331, .77 Em, III) is 
situated in the endosperm near the base of the 

Various processes, some dry, others wet, are 
employed for removing the pericarp and spermo- 
derm from the seed. In the West Indies and South 
America, the larger part of the fruit flesh is first 
Fig. 332. Coffee. Cross- removed by a pulper, after which the pulp still 
section of bean showing adhering is loosened by a fermentation process and 

folded endosperm with J k 

hard and soft tissues, washed away by water. After drying, the spermo- 
derm and endocarp are broken away from the seed 
and separated by winnowing. The spermoderm is also removed from the 
surface but not from the cleft. Roasting swells the seed greatly, changes 
its color to dark brown, and develops the characteristic odor and flavor 
of roasted coffee by the formation of caffeol and other substances. 





As fresh material is not obtainable in the temperate zone except from 
botanical gardens, alcoholic or dried specimens must be used for histo- 
logical studies. 

Coffee beans, as found on the market, whether unroasted or roasted, 
consist only of the endosperm, embryo, and that portion of the spermo- 
derm within the cleft, although occa- 
sionally fragments of the pericarp 
occur with the beans as an acci- 
dental impurity. The pericarp may 
be sectioned dry, the endosperm 
after soaking in water. 

The Pericarp after drying is of 
a dark color about 0.5 mm. thick. 
As the outer layers are soft and 
the endocarp hard, no little difficulty 
is experienced in preparing sections. 
For cutting transverse sections, the 
dry material freed from the seed 
may be embedded in hard paraffine 
and cut with a strong razor or 
microtome knife, taking care that 
the palisade cells and endocarp, 
which are liable to separate from the 
outer layers, are not lost. Staining 
with safranin, naphthylene blue or 
methylene blue is recommended. 

1. The Epicarp Cells (Figs. 333 

and 334, ep) are 15-35 ," broad, 

sharply polygonal, occasionally four- Fig. 333. Coffee. Cross section of hull and 

•j j -ix. i_ 11 j bean. Pericarp consists of I epicarp, 2,3 

Sided, With brown walls and con" layers Q f mcsocarp with 4 fibro-vascular 

tents. Stomata with two accom- bundle, 5 palisade layer, and 6 endocarp; 

ss spermoderm consists of 8 sclerenchyma 
panymg cells Similar to the guard and" g parenchyma; end endosperm. 

cells in form occur here and there. ( TscHIRCH and Oesterm.) 

2. Mesocarp (Figs. ^3> 334, and 335). Proceeding inward, the 
cells increase in size until they reach a maximum of about 100 pt. Their 
walls are thick and either brown or yellow. Brown amorphous masses 
and occasionally large crystals are noticeable in the outer layers. In 



the innermost part of the mesocarp, through which ramify the fibro- 
vascular bundles, the cells are commonly compressed. The strongly 
developed bundles contain bast fibers up to i mm. long and 25 /* broad, 
with thick walls and narrow lumen, spiral vessels mostly narrower than 
the bast fibers, but with noticeably thick spirals, pitted vessels, and other 
less conspicuous elements. 

3. Palisade Layer (Fig. 333, 5). These cells are greatly elongated 
in radial directions and have walls of mucilaginous structure which swell 

FlG. 334. • Coffee. Surface view of ep epicarp Fig. 335. Coffee. Elements of pericarp in 
and p outer parenchyma of mesocarp. surface view, p parenchyma; bp paren- 

X160. (Moellek.) chyma of nbro-vascular bundle; 6 bast 

fiber; sp spiral vessel. X160. (Moeixer.) 

in water. Because of these peculiarities, as well as the difficulties of 
cutting so soft a tissue when adjoining a hard coat like the endocarp, 
special care must be exercised in preparing sections. Safranin stains 
the swollen wall carmine, but does not affect the yellowish contents. 
Vogl states that naphthylene blue colors both the walls and contents blue- 

4. Endocarp (Fig. 333, 6; Fig. 336). Closely united with the palisade 
layer is the thin, but hard, buff -colored endocarp resembling in macro- 
scopic and microscopic structure the endocarp of the apple. The fibers 
cross one another at various angles, but in the outer layers their general 
direction is longitudinal, while in the inner layer it is transverse. The 
fibers of the inner layer are thin-walled, whereas those of the other layers 
are thick-walled and conspicuously porous. 

Spermoderm. Although the spermoderm is removed from the sur- 
face of most of the seeds in preparing them for market, fragments suff; 



cient for study may often be obtained from unroasted coffee. Within 
the cleft the spermoderm is almost always intact, even after roasting, 

Fig. 336. Coffee. Sclerenchyma fibers of endocarp. X160. (Moeixer.) 

and may be readily removed in one piece after soaking the seed for some 
hours in water. 

1. Sclerenchyma Cells (Fig. 333, 8; Fig. 337, st) form the character- 
istic outer layer. In the early stages of development the coat is uninter- 

Fig. 337. Coffee. Spermoderm in surface view, st sclerenchyma; p compressed paren- 
chyma. X 160. (Moeller.) 

rupted, but in the mature seed, as a result of more rapid growth of adjoin- 
ing tissues, they are more or less detached, occurring singly, in pairs or 

43 2 


in groups, either widely separated or with only small intercellular spaces 
between them. They vary from less than ioo n to over i mm. in length 
and from 15-50 n in breadth. The longer cells, occurring in groups 
within the cleft, are straight and narrow, resembling bast fibers, while 
the medium and shorter cells, occurring both on the surface and in the 
cleft, are broader and more irregular in outline, vermiform and club- 
shaped forms predominating, although triangular and various fantastic 
shapes are not uncommon. Great variations in the thickness of the 
walls and the size and number of the pores are also noticeable. 

2. Parenchyma Cells (Fig. 333, p; Fig. 337, p), more or less obliter- 
ated, form the remainder of the spermoderm. Occasionally cells with 
beaded walls are distinguishable, but in most parts the cells are not 
clearly evident, the tissue appearing like a structureless membrane. 
Through this tissue in the cleft runs the raphe, with narrow spiral vessels, 
which are best seen after treatment with alkali or chloral hydrate. 

Endosperm (Figs. 333 and 338). Coffee, like the date stone and the 
ivory-nut, contains only the minutest traces of starch, the carbohydrate 


Fig. 338. Coffee. Cross section of outer layers of endosperm showing knotty thickenings 
of cell walls. X160. (Moeller.) 

reserve material being largely in the form of cellulose stored up in the 
cell-walls of the endosperm. In sections, the cell-walls, except in the 
outer layers, appear to be knotty-thickened, owing to the large pores 
by which they are pierced, the double walls in the knots ranging up to 
20 (i in thickness. The cells are smallest in the cuticularized outer layer, 
where they are 15-50 p in diameter, but in the inner layers they often 
reach 100 fi. To the naked eye the central portion of the endosperm 
(Fig 33 2 ) has a somewhat different appearance from the remainder, due 
to the presence of an interrupted scries of tangentially elongated cells, 

COFFEE. 433 

the walls of which, excepting the middle lamella, are composed of a 
mucilaginous substance, and consequently disappear on treatment with 
water. It is in this mucilaginous tissue near the base that the minute 
embryo is embedded. Tschirch regards this soft tissue as useful in facili- 
tating the absorption of the reserve material by the sprouting plantlet. 

Treatment with various reagents and stains, such as chlorzinc iodine, 
iodine-sulphuric acid, naphthylene blue, and safranin, show that the thick- 
ened cell-walls consist of cellulose. Reagents also serve for the identi- 
fication of the cell-contents. For example, concentrated sulphuric acid 
produces a fine, red color showing the presence of sugars, iron salts give 
a green color due to tannic acid, various reagents show the presence 
of proteids, sometimes in the form of aleurone grains, while numerous 
micro-tests given by Tschirch and Oesterle confirm the presence of caf- 
fein. Vogl notes that sections are colored an intense yellow by caustic 
potash and soda, and a green-yellow changing to green by ammonia. 
Heating with chloral hydrate imparts a blue-green coloration to the 
contents, but this reaction, as well as some of the others, is not distinct 
in the case of roasted coffee, and is therefore of no practical value. 

The. Embryo (Fig. 331, III) may be obtained by cutting a bean, previ- 
ously soaked overnight in water, through the cleft and carefully splitting 
open the endosperm through the mucilage cells. 
After longer soaking in water or in dilute alkali, 
the embryo bursts through the endosperm at the 
basal end. The blunt radicle is 3-4 mm. long, 
the heart-shaped cotyledons 1-2 mm. long. After 
clearing with alkali, or better with Javelle water Fig. 339. Coffee. Tis- 
or chloral hydrate, the cotyledons are seen to have ZL ^^(MceT- 
three pairs of sparingly branching nerves. The LEE -) 
small cells and procambium bundles filled with protoplasm and fat are 
of little diagnostic importance (Fig. 339). 


Coffee reaches the consumer either "green" (unroasted) or roasted, 
and in the latter case either whole or ground. Roasting, as ordinarily 
conducted, changes the color of the bean to a rich brown which renders 
most' of the microchemical tests of little value, but does not seriously 
obscure the structure of either the spermoderm or endosperm. 

Whole Coffee, also known as "coffee beans" and "coffee berries," 
is characterized by the form and horny texture of the endosperm, and the 


presence of the spermoderm or "chaff" in the cleft. The spermoderm 
without special preparation is readily identified under the microscope by 
the more or less isolated sclerenchyma cells; the endosperm, in section, 
by the knotty-thickened walls, and the absence of more than the faintest 
trace of starch. 

The adulteration of genuine coffee with beans previously used for 
the manufacture of coffee extract cannot be detected by microscopical 
examination, although the coating of these beans, as well as of inferior 
grades of unextracted coffee, with various pigments, is sometimes evident 
in microscopic sections. 

Ground Coffee varies in fineness from coarsely crushed beans to a 
powder passing a i mm. sieve. Usually there is an abundance of frag- 
ments large enough to section with a razor, either dry or after soaking, 
thus permitting an examination of the cell-walls of the endosperm (Fig. 
338). The papery flakes of spermoderm (Fig. 337) may be picked out 
with forceps. 

If a handful is stirred with cold water, true coffee, except for a few 
over-ruaa^a tra^menrs; 3oats; whereas the common adulterants, including 
peas and other legumes, cereal grains, chicory and other roots, imitation 
coffee, etc., sink rapidly to the bottom, their nature being determined by 
microscopic examination. Artificial coffee made from oil-seed products 
is said to float. 

Outer Coffee Hulls, consisting of the epicarp, the mesocarp, and 
traces of the palisade layer, are utilized by the Arabians in the prepara- 
tion of a fermented liquor, "Kischer" or "Gischr." These hulls are 
also exported from coffee- growing regions under the names "Sultan 
coffee," and "sacca-coffee," as an adulterant of coffee, the fact that they 
are a product of the coffee tree and the claim that they contain a certain 
amount of caffein and other valuable constituents being offered as excuses 
for their use. These claims are not worthy of consideration, as the 
product is even more worthless than most of the common substitutes. 

The hulls occur in small amount in genuine coffee, but when the 
amount is considerable, adulteration is indicated. They are of a black 
color, with a small ring about 2 mm. in diameter at the upper end, in 
the middle of which is the scar of the style. Highly characteristic ele- 
. ments being absent, it is often difficult to identify the material in pow- 
der form. The epicarp (Fig. 334, ep) and brown mesocarp resemble 
the corresponding tissues of the carob bean, though the epicarp of coffee 
may be distinguished by the stomata with two adjoining cells and the 

COFFEE. 435 

thicker-walled mesocarp, the contents of which do not give the blue or 
violet color on warming with alkali. 

Inner Coffee Hulls, consisting of endocarp with particles of the ad- 
hering palisade layers, are parchment-like in texture and of a buff color. 
Although they have scarcely more value than sawdust, they have been used 
in the United States as an adulterant of wheat bran and other cattle foods. 
Charred hulls have recently been detected by the writer in ground pepper. 
This material is characterized by the groups of crossing fibers (Fig. 336). 

Artificial Coffee Beans moulded from dough, sometimes with the 
admixture of chicory and other materials, resemble genuine roasted 
beans in form and color, but are distinguished by the exact correspon- 
dence of beans from the same mould, the shallow cleft, the absence 
of chaff in the cleft, the granular texture, and other physical charac- 
teristics which can be learned only by experience. As usually prepared, 
they sink at once in cold water. Under the microscope, starch and other 
elements of the constituents are identified. 

Artificial Broken Coffee similar to the artificial beans, but made in 
irregular lumps, not moulded in the forms of beans, resembles closely 
broken coffee beans and serves as an adulterant both for whole and ground 
coffee. Another form of artificial coffee much used in America consists 
of pea hulls, cereal matter, and molasses, made into small pellets. 

The Fruits and Seeds used most commonly as substitutes or adulter- 
ants of coffee are wheat, rye, barley, maize, and other cereals, also cereal 
products, such as bran, middlings, bread, etc.; peas, beans, lupines, 
cassia seeds, astragalus seeds, Parkia seeds, chick peas, soja beans, pea- 
nuts, and other leguminous seeds; dried figs, prunes, pears, bananas, and 
carob bean pods; date stones, ivory nuts, acorns, grape seeds, fruit of the 
wax palm, cola nut (Mussaende-Kaffee), and false flax. 

Roots. Chicory is by far the commonest root used in coffee. It is 
gummy, sweet to the taste, colors cold water a deep yellow, and is identi- 
fied by the vessels and latex cells. Other roots used are dandelion, 
beet, turnip, and carrot, all of these being adulterants of chicory. 

Coffee Substitutes (European). Among the hundreds of proprie- 
tary articles sold in Europe as substitutes for coffee are the following: 
"Kanon" (rye, coffee, chicory); "Datel Kaffee" (wheat, chicory, figs, 
and coffee); "Homeopathischer Gesundheitskaffee " (wheat, chicory, 
and cocoa shells); "Hygienischer Nahrkaffee" (cereals and acorns); 
"German Soda Coffee" (cereals, chicory, and sodium carbonate); 
"Jamaika Kaffee" (barley); " Mokka-Sakka- Kaffee " (barley and other 


constituents); " Saladinkaffee " (maize); " Malto-Kaffee " (malt or 
mixtures of malt and other cereals); " Kraft-Kaffee, " " Frucht-Kaffee " 
and "Allerwelts Kaffee" (lupine seeds); "Mogdad," "Neger," and 
" Stephanie-Kaffee " (seeds of Cassia occidentalis and C. sophora); 
"Sudan- Kaffee" (seeds of Parkia Ajricana and P biglobosa); "Schwe- 
dische Kontinental- Kaffee" (seeds of Astragalus boeticus); "Deutscher" 
or "Franzosischer Kaffee" (chick pea); "Ungarischer Kaffee" (coffee, 
lupines, and chicory); " Af ricanischer Nussbohnen Kaffee" (peanuts); 
"Bayrischer Kaffee" (beets, figs, rye, and legumes); "Mokara" or "Fei- 
genkaffee" (figs); "Figine" (figs and chicory); "Melilotin Kaffee" (coffee, 
chicory, and date stones); "Almond Coffee" (originally made of the 
tubers of Cyperus esculentus L., later of acorns, chicory, and dandelion 
root); "Frank Kaffee" (chicory); "Cafe" de Rheims" and "Rations 
Coffee" of the French army (coffee and chicory); "Domkaffee" 

Coffee Substitutes (American). Among the preparations made in 
the United States, the following have been found to consist of various 
preparations of cereals: "Ralston Cereal Coffee," "Grain-O," "Postum 
Cereal Coffee," "Ayer's Hygienic Substitute for Coffee," "New Era 
Hygienic Coffee," "Shredded Cereal Coffee," "J. W. Clark's Phosphi 
Cereal Nervine Coffee," and many others. Other preparations are: 
"Old Grist Mill Entire Wheat Coffee" (wheat, peas, and real coffee); 
"Fischer Mills Fresh Roasted Malt Coffee;" "Kneipp Malt Coffee" 
(barley or malt); "Kentucky Coffee" (Caesalpinia pidcherrima). 


See General Bibliography, pp. 671-674: Berg (3); Greenish (14); Hanausek, T. F. 

(10); Hassall (19); Leach (25); Mace (26); Moeller (29, 30, 31, 32); Molisch (^)\ 

Planchon et Collin (34); Schimper (37); Tschirch u. Oesterle (40); Villiers et Collin 

(42); Yogi (43, 45). 

Brunotte: A Pseudo-substitute of Coffee. Rev. internat. falsificat. 1896, 9, 48. 

Cazeneuve: Artificial Coffee Beans. Petit mon. de !a pharm. 1894, 1513. 

Coster, Hoorn u. M azure: Falsifications observers en Holland. Rev. internat. 
falsificat. 1887-88, 1, 162. 1890, 4, 7. 

Cribb: Note on (1) Samples of Coffee Containing Added Starch; (2) Sample of Artifi- 
cial Coffee Berries. Analyst. 1902, 27, 114. 

Draper: Detection of Coffee Adulterations. Phil. Mag. 34, 104. 

Dustan: Der sogenannte Mussaenda-Kaffee von Reunion. Ztschr. Nahr.-Unters. 
Hyg. 1890, 4, 13. 

Fricke: Sogenannter Congo-Kaffee. Ztschr. angew. Chem. 1889, 2, 121. 

COFFEE. 437 

Gawalowski: Ersatzmittel fur Kaffeebohnen. Ztschr. Nahr.-Unters. Hyg. 1896, 9, 

Greinert: Ueber Negerkaffee. Pharm. Ztg. 1889, 34, 192. 
Gundriser: Ueber ein Kaffeesurrogat aus den Samen der blauen Lupine (Lupinus 

angustijolius). Ztschr. Nahr.-Unters. Hyg. 1892, 6, 373. 
Hanausek, E.: Kunstliche Kaffeebohnen. Ztschr. Nahr.-Unters. Hyg. 1890, 4, 25, 

Hanausek, T. F.: Dattelkeme als Kaffeesurrogat. Chem. Ztg. 1886, 10, 701. 
Hanausek, T. F.: Kunstliche Kaffeebohnen. Ztschr. Nahr.-Unters. Hyg. 1889, 


Hanausek, T. F.: Die Entwicklungsgeschichte der Frucht und des Samens von Cofjea, 

arabica. Ztschr. Nahr.-Unters. Hyg. 1890, 4, 237, 257. 1891, 5, 185, 218. 1893, 

7, 85, 195. 
Hanausek, T. F.: Zum Bau der Kaffeebohnen. 66. Vers, deutsch, Naturf. u. Aerzte. 

Wien, 1894. 
James: Le cafe torrifii?, engrains, factice. Revue d'hyg. 1890, No. 12. 
Konig: Kunstkaffee. Chem. Centralbl. 1889, 20, 1, 51. 
Konig: Die Friichte der Wachspalme als Kaffeesurrogate. Centr.-Org. f. \Yaarenk. 

u. Techn. 1891, 1, 1. 
Kornauth: Communications diverses concernant les denrees alimentaires et les 

boissons. Rev. internat. falsificat. 1889-90, 3, 195. 
Kornauth: Beitrage zur chemischen und mikroskopischen Untersuchung des Kaffees 

und der Kaffeesurrogate. Hilger, Mitth. Lab. angew. Chem. Erlangen, III 

Heft. Munchen, 1890, 1. 
Kornauth: Zur Beurtheilungen der Kaffeesurrogate. Ztschr. angew. Chem. 1891, 


Mansfeld: Bericht iiber die Thatigkeit der Untersuchungsanstalt des Allgemeinen oster- 
reichischen Apothekervereines und des Wiener Apotheker-Hauptgremiums. Ztschr. 
Nahr.-Unters. Hyg. 1896, 10, 336. 

Mansfeld: Kaffeesurrogate. Jahresber. Unters. allg. osterr. Apoth.-Ver. 1901, 10. 

Moeixer: Ueber Mogdad-Kaffee. Pharm. Centralh. 22, 133. Dingler's Polytechn. 
Jour. 1880, 237, 61. 

Morpurgo: Eine einfache Methode zur Entdeckung kiinstlicher Farbungen der Kaffee- 
bohnen. Ztschr. Nahr.-Unters. Hyg. 1898, 6, 9. 

Nevtnny: Die Nahrungs- und Genussmittel Wiens. Ztschr. Nahr.-Unters. Hyg. 1887, 
1, 21. 

Nevinny: Zur Verfalschung des Feigenkaffees. Ztschr. Nahr.-Unters. Hyg. 1887, 

1, 85. 

Pade: Neue Falschungen des Kaffees. Chem. Centralbl. 1889, 20, 2. 
Portele: Kunstliche Kaffeebohnen. Ztschr. Nahr.-Unters Hyg. 1889, 3, 221. 
Raumer: Ein neues Kaffeesurrogate. Forschber. Lebensm. Hyg. 1894, 1, 293. 
Raumer: Ueber den Nachweis kiinstlicher Farbungen bei Rohkaffee. Forschber. 

Lebensm. Hyg. 1896, 3, 333. 
Reuter: Beitrag zur Kenntniss der Bestandtheile des Mogdad-Kaffees. Pharm. 

Centralh. 1889, 30, 494. 
RoHRiG: Afrikanischer Nussbohnenkaffee. Forschber. Lebensm. Hyg. 1895, 2, 15. 


Rtjfitn: Fabrikation, Veranderungen und Faischungen der Cichorien. Ann. chim. 

anal. 1898, 3, 114. 
Samelson: Ueber Kunstkaffee. Ztschr. angew. Chem. 1890, 482. 
Street: Coffee Hulls. New Jersey Agr. Expt. Sta. Bull. 160, 1902. 
Stutzer: Ueber Kunstkaffee. Ztschr. angew. Chem. 1888, 1, 699. 1890, 549. 
Trillich: Ueber Malzkaffee und Kaffeesurrogate. Ztschr. angew. Chem. 1891, 540. 
Trillich: Kaffee und Kaffeesurrogate. Ztschr. angew. Chem. 1896, 440. 
Trillich: Ueber Kaflee mit thranenformigen Tohnen. Ztschr. offentl. Chem. 1898, 

Waage: Ueber kiinstliche Kaffeebohnen. Apoth.-Ztg. 1890, 5, 219. 
Wolffenstein: Untersuchung einiger Kaffeepraparate. Ztschr. angew. Chem. 1890, 



Liberian coffee (Coffea Liberica Bull.) is found wild and cultivated in 
Liberia and the whole of the Guinea coast. The limited product is 
exported chiefly to England and the Continent. 

The fruit is extremely large, averaging 1 toi| inches in length, ellip- 
soidal, and pointed at both ends. Compared with C. Arabica the pulp 
is thicker, the parchment hard and brittle, never clear, and the spermo- 
derm or silver skin stronger, tougher and more tightly rolled into the 
deep, narrow furrow. The bean also is unusually large, peculiar in 
form, dark brown in color, and heavy in weight. Although coarser 
flavored, owing to its strength it is well adapted for admixture with better 

Hartwich notes that the embryo of C. Liberica is 7.5 mm. long, that 
of C. Arabica only 4 mm.; also that the stone cells of the spermoderm 
are 880 fi long and 51/4 broad in the former, while they are but 484 fi 
long and 41 [i broad in the latter species. 


Hartwich: Coffea liberica. Schw. Woch. Chem. Pharm 1896,34,473. 


The oldest and commonest substitute for coffee is the root of chicory 
(Cichorium Intybus L., order Composite), a native of Europe, where 
it is also extensively cultivated. The tap root is spindle-shaped, sparingly 
branched, while fresh, fleshy with a milky juice, after drying, shriveled, 
hard, horny, on the outer surface brown, and often spirally wrinkled. 

tMICORY. 439 

Cross sections examined under a lens show the radiating pnioem groups, 
the xylem elements with broad lumens, and the narrow radiating medul- 
lary rays. 

The reserve material is largely in the form of inulin. 



i. The Cork (Fig. 340) tissue consists of a few layers of rather flat 
cells, with thin brown walls. In surface view they are often ill-defined. 

2. Cortex (Fig. 341). The parenchymatous ground tissue contains 
numerous branching and anastomosing latex tubes 
(sch) 6-10 fi broad, with granular contents, which 
are especially conspicuous after staining. Inulin 
occurs in the parenchyma, but being soluble in 
water, is evident only in mounts of alcohol material, 
in which it forms sphasro-crystals. 

3. Bast (Fig. 341). The sieve tubes (s) are dis- 
tinguished from the latex tubes by their occur- 
rence in bundles, the absence of branches, and the 

,, . , . , -«.t • 1 1 Fig. 340. Chicory (Ci- 

callus of the sieve plates. Neither the cortex nor chorium Tntybus). Cork 

the bast contains any sclerenchyma elements what- £ssue °l i ^ ot "^i&j" 

ever. (Moeixer.) 

4. Wood (Fig. 342). The most conspicuous elements of the root 
are the vessels (g) made up of short (usually less than 200 ft), moderately 
broad, (usually 20-50 fi) members, with diagonal, porous or non-porous 
cross walls. The side walls are characterized by numerous moderately 
elongated transverse pores. Usually the vessels are in radial rows or 
in groups, seldom isolated. Fuchsin stains them an intense red. 

Of less diagnostic value are the thickly porous parenchyma cells and 
the rather thin- walled wood fibers (/), with diagonal clefts. The narrow 
medullary rays consist cf one or two (rarely three) rows of cells. 


Chicory as used in coffee is in irregular, soft, deep brown grains, 
with a sweetish taste. It sinks in water, imparting to it a yellow-brown 
coloration. The important elements are the vessels (Fig. 342, g) consisting 
of short joints, with moderately elongated, transversely arranged pores, 
and the branching latex tubes (Fig. 341, sch) with granular contents. In 
some fragments one finds numerous vessels, in others numerous latex tubes 
in a mass of brown parenchyma. 



Common adulterants are the roots of dandelion, carrot, beet, and 
turnip, as well as cereal matter. Dandelion (p. 441) and carrot (p. 418) 
are distinguished by the elongated narrow pores of the vessels. The 

m ! g 

1^. ,1 


rp - 

Fig. 341. Chicory. Bark of root in radial 
section, rp cortex parenchyma; sch latex 
tubes; s sieve tube; bp bast parenchyma; 
m medullary rays. X160. (Moellek.) 

Fig. 342. Chicory. Wood of root in 
tangential section, g pitted vessels 
with qu perforation; hp wood pa- 
renchyma; Zwood fibers; m medul- 
lary ray. X160. (Moelleiu) 

former root, like chicory, contains latex tubes. The vessels of the. white 
turnip (p. 419) have pores similar to those of chicory; latex tubes, how- 
ever, are lacking. Unusually broad meshes characterize the vessels of 
the beet (p. 417). 


See General Bibliography, pp. 671-674: Greenish (14); Hanausek, T. F. (10, 16); 
Hassall(io); Leach (25); Mace" (26); Moeller(2o); Planchonet Collin (34); Tschirch 
u. Oesterle (40); Villiers et Collin (42); Vogl (14, 45). 

See also Bibliography of Coffee, pp. 436-438. 


The root of the common dandelion (Leontodon Taraxacum L., order 
Composite) is often mixed with chicory. It is thicker and more branched 
than the latter, and has a more even fracture. The bark is white, with 
delicate concentric rings; the wood yellow, without rays. 




The bark elements (Fig. 343) are practically the same as those of 
chicory. The concentric rings are only evident in cross section. 

More characteristic is the structure 
of the wood (Fig. 344). The vessels 
(g) are irregularly distributed, not sep- 
arated by the medullary rays into distinct 
groups. They are somewhat broader 
(up to 80 n) than those of chicory, and 
have much longer pores, resembling those 
of scalariform vessels. Less noteworthy 
is the absence of wood fibers, as these 

Fig. 343. Dandelion {Leontodon 
Taraxacum) . Bark of root in longi- 
tudinal section showing latex tubes. 
(Tschirch.) . 

Fig. 344. Dandelion. Wood of root in longi- 
tudinal section, g reticulated vessels with qu 
perforation; hp wood parenchyma; m medul- 
lary ray. Xl6o. (MOELLER.) 

arc not easily found in chicory. The reserve material exists largely as 
inulin, which in alcohol material forms sphsero-crystals. 


The greater length of the pores in the vessels (Fig. 344 g) serves to 
distinguish this root from chicory. Latex tubes (Fig. 343) are present in 
both roots. 


See General Bibliography, pp. 671-674: Moeller (29, 32); Planchonet Collin (34); 
Tschirch u. Oesterle (40); Vogl (44, 45). 



Chocolate and Cocoa are products of the "beans" or seeds of several 
small trees, natives of tropical America, of which Theobroma Cacao L. 
(order Sterculiacece) is by far the most important. The value of cocoa 
beans was known to the aborigines, especially the Aztecs of Mexico and 
Peru, who prepared from them beverages and foods. They were brought 
to the notice of Europeans by Cortez and other explorers, but were not 
extensively imported into Europe until the seventeenth century, about 
the time tea and coffee were introduced from the East. Theobroma 
(food of the Gods), the generic name assigned by Linnaeus, suggests the 
high esteem with which people in his day regarded the seed. At present 
the world's supply comes chiefly from Venezuela, Guiana, Ecuador, 
Brazil, Trinidad, Cuba, Mexico, and other regions bordering on the 
Gulf of Mexico, being gathered in these regions from both wild and 
cultivated trees, and also to some extent from Java, Ceylon, Africa and 
other parts of the Old World, where the tree has been successfully culti- 
vated. Cocoa trees with their large dark-green leaves and clusters of 
fragrant red blossoms are among the most beautiful objects of the 
Tropics, and the fruit, borne on the trunk and old wood of the tree, is a 
never ending source of wonder to travelers. 

The yellow or brown cocoa fruit is from 12-18 cm. long, from 5-9 
cm. wide, and has 10 ridges passing from the base to the apex, giving 
the surface a melon-like appearance (Fig. 345, I and II). It contains 
from 35 to 75 seeds in 5 rows, embedded in a mucilaginous substance. 

The seeds after being removed from the fruit are dried at once in 
some localities, but the better grades are first subjected to a fermenta- 
tion process, which destroys certain bitter and acrid constituents. 

Cocoa beans (Fig. 345, III-VI) as found on the market consist of the 
anatropous seeds, often with more or less of the pulpy inner pericarp 
adhering. They are irregularly ellipsoidal, 15-30 mm. long, somewhat 
flattened, and vary from reddish brown to dark brown in color. The 
hilum at the broader end and the chalaza at the narrower end are con- 
nected by the raphe, which runs along one of the narrow sides and divides 
into numerous branches at the chalaza. The so-called "shell," consist- 
ing of spermoderm with portions of the inner pericarp adhering to the 
outer surface and the perisperm to the inner surface, is thin and brittle, 
readily breaking away from the cotyledons. There is no endosperm, 
the reserve material being entirely in the chocolate-colored embryo con- 



sisting of two thick and curiously folded cotyledons and a hard radicle 
about one-third the length of the seed situated at the hilum end. On 
crushing the seed the radicle separates and the cotyledons break into 

FIG. 345. Cocoa {Theobroma Cacao), /entire fruit, Xi; //fruit in cross section. Ill 
seed (cocoa bean), natural size; IV seed deprived of spermoderm; V seed in longitu- 
dinal section, showing radicle (germ) ; VI seed in cross section. (Winton.) 

angular pieces known as cocoa nibs, from which are prepared the choco- 
late and cocoa of commerce. 

Over 50 per cent of the dry embryo consists of fat, the remaining 
constituents being starch* proteids, theobromin, caffein, a tannin sub- 
stance known as cocoa red, and other substances in smaller amount. 


Cocoa beans, obtainable from any manufacturer of cocoa products, 
are suitable for microscopic study. Transverse sections are conveniently 
cut dry, depending on subsequent treatment with reagents to swell out 
the tissues. If sections of the shell are soaked for a few minutes in 
Javelle water, the collapsed cells, particularly those of the endocarp and 
the outer epidermis of the spermoderm, assume their normal form and the 
tissues, after washing in dilute acetic acid, are suitably cleared for stain- 
ing with safranin or some other dye. Sections of the cotyledons are first 
freed from fat by a suitable solvent and afterwards mounted either in 
glycerine or water. 

Pericarp. Adhering to the surface of most grades of beans is a thin 
coat consisting of the cells of the inner layers of the mesocarp or fruit 
pulp and the endocarp. 



i. Mesocarp (Fig. 346, mes). The cells are elongated, often branching, 
with large intercellular spaces. On soaking in water they become slimy 
and, together with the endocarp, separate easily from the spermoderm. 

2. The Endocarp (Figs. 346 and 347, end) is made up of narrow elon- 
gated cells running transversely or diagonally about the seed and forming 
the so-called cross-cell layer. These cells are about 15 // wide and often 
reach a length of 200-300 p.. 

Spermoderm. 1. The Outer Epidermis (Figs. 346 and 347, ep), con- 
sisting of longitudinally elongated, polygonal cells (30-50 /j. broad and 

Fig. 346. Cocoa. Cross section of outer portion of bean, mes inner layers of mesocarp; 
end endocarp; spermoderm consists of ep outer epidermis, muc mucilage cells, p spongy 
parenchyma, st stone cells and Ip nutritive layer; N perisperm consists of epidermal 
and obliterated layers; C cotyledon. (Tschirch.) 

up to 200 ft long), is clearly seen in surface preparations, underlying 
the cross cells of the endocarp. Owing to their collapsed condition, this 
layer is not distinct in sections mounted in water, but on treatment with 
Javelle water, the cells swell to their natural size and the thick cuticle 
becomes evident. 



2. Mucilage Cells (Fig. 346, muc) underlie the epidermis, forming 
what at first sight appears to be a broad hyaline coat. They do not, 
however, form a continuous coat, but a series of pockets separated by 
tissues of the third layer. Safranin stains the layer in cross section a 
clear rose color and makes the radial walls more distinct. 

3. Spongy Parenchyma (p). Numerous layers of spongy paren- 
chyma cells, through which pass the bundles of the raphe and its branches, 
form the third coat. Narrow spiral vessels readily separating from 
the other elements, characterize the bundles. 

4. Stone Cells (Fig. 346, st; Fig. 349, d). The cells of the next layer 
are thickened on the inner and radial walls. In surface view they are 
polygonal, often elongated, varying up to 25 fi long. The double walls 
are about. 5 /x thick. Here and there groups of these cells are not thick- 

FlG. 347. Cocoa. Outer elements of shell. 
ep epidermis of spermoderm; end endocarp 
(cross cells); p parenchyma of mesocarp. 
X160. (Moeller.) 

Fig. 348. Cocoa. Cross section of outer 
portion of cotyledon, showing hairs 
(Mitscherlichian bodies) and starch 
parenchyma. (Moeller.) 

ened at all, permitting, according to Tschirch and Oesterle, an exchange 
of cell liquids. 

5. Nutritive Layer (Fig. 346, lp). Several rows of cells of this layer 
contain in earlier stages of development cell-contents which later are 
employed in building up the seed, leaving at maturity only obliterated 


6. The Inner Epidermis is indistinct. 

Perisperm. (Fig. 346, N). The "silver" coat, formerly regarded 
as endosperm but later shown by Tschirch and Oesterle to be perisperm, 
envelops the seed and penetrates between the folds of the cotyledons. 

1. Epidermis A single layer of polygonal cells (15-30 fi) with distinct 
walls (double walls 3 ft) forms a coat similar to the aleurone cells of 
many seeds. The cell contents are yellow or white and consist of 
fatty matter in aggregates, and protein. This layer does not penetrate 
between the cotyledons. 

2. Obliterated Cells comprise the remainder of the perisperm. They 
contain fat in numerous large blade-shaped crystals, often in fan-like 
clusters, and also dense sphero-aggregates. 

Embryo. The bulk of the seed consists of the fleshy cotyledons con- 
taining over half their dry weight of fat. 

1. The Epidermis (Figs. 348 and 349) is made up of polygonal cells 
and remarkable several-celled hairs (tr) named in honor of their discoverer 
" Mitscherlichian bodies." These latter consist of a single row of cells 
near the base, but expand at the outer end into a club-shaped body often 
several cells broad. Vogl has rightly observed that these hairs occur less 
often on the surface of the cotyledon adjoining the perisperm than in 
the folds, and Tschirch and Oesterle, that they are still more abundant 
on the radicle. The perisperm, particularly that portion wkhin the 
folds of the cotyledons, often has these hairs adhering to its inner surface. 
Both the hairs and the other epidermal cells contain small brown bodies, 
which, according to Vogl, are colored blood-red by chloral, olive-brown 
by ferric chloride, and bright yellow by ammonia, the latter reagent also 
causing the grains to swell. These reactions are not always decisive. 

2. Ground Tissue (Fig. 348). The cells in the interior of the cotyle- 
dons either contain starch and aleurone grains embedded in fat, or a 
pigment varying from violet to brown in color. Fat, the chief constituent 
of the embryo, occurs either in rosettes of needle-shaped crystals or in 
compact masses. Starch is present in amounts varying up to 10 per 
cent, the rounded grains (4-12 ,«), each with a distinct hilum, resembling 
closely those of allspice and cinnamon. The grains occur singly, in 
pairs, or in triplets. They stain slowly with iodine, even after the re- 
moval of the fat. The aleurone grains are usually smaller than the 
starch grains and contain several globoids, but larger grains with crystal- 
loids are also found here and there. Both the starch and aleurone grains, 
the latter being the less abundant, are clearly differentiated by extracting 



sections with ether and mounting in chlorzinc iodine. Scattered among 
these cells are the pigment cells containing a substance varying from 
violet to brown in color known as cocoa red, which, together with theo- 
bromin, caffein and dextrose, is formed by the action of an enzyme 
on a glucoside originally present in the bean. Usually this substance 
becomes blood-red with concentrated sulphuric acid, gray-blue with 
ammonia, greenish -yellow with caustic soda, and olive with ferric chloride, 
although the color reactions vary greatly in different samples, owing 

A B 


FlG. 349. Cocoa. A perisperm (silver coat) consisting of epidermis and parenchyma: 
K and / crystals; tr adhering hairs (Mitscherlichian bodies) from epidermis of cotyledon. 
B elements of cocoa powder, showing c cotyledon tissues with fat cells and pigment 
cells, also p parenchyma, sp spiral vessels and d stone cell layer of shell (spermoderm). 
X160. (MOELLER.) 

possibly to lack of uniformity in the process of fermentation, roasting, 
etc. Tschirch and Oesterle describe methods for separating theobromin 
gold chloride and theobromin silver nitrate, but these, although of 
scientific interest, are of little value in diagnosis. Caffein also occurs in 
small amounts in the embryo, but its presence is best demonstrated by 
purely chemical means. 


Plain Chocolate. The first stages in the manufacture of both choco- 
late and cocoa are the same. 

After removing stones, chips and other impurities, the beans are 
roasted, thus developing a desirable flavor and facilitating the processes 


of separation from the shells and grinding. The beans are then crushed 
by machinery and separated from the shells. In some factories the hard 
"germs" (radicles) are also removed. 

The broken cotyledons, free from shells, known as "cocoa nibs," 
are next ground in the chocolate mill. The heat of grinding melts the 
fat which makes up about half the weight of the nibs, and the ground 
product runs out of the mill as a thin paste. This paste, after cooling 
in moulds, is plain or unsweetened chocolate, also known as cocoa mass. 

The most characteristic tissues of the embryo are the multi -cellular 
bodies of the epidermis (Fig. 349), but these are not numerous and are 
largely destroyed in grinding. Of chief value in identification are the starch 
grains (Fig- 348), which, although much like the grains of allspice and cin- 
namon, do not resemble those of any common adulterant. The violet or 
brown contents of the pigment cells are also of some diagnostic impor- 
tance, though the reactions are often misleading. Tissues of the spermo- 
derm (Fig. 347) are exceedingly rare in cocoa products made from care- 
fully shelled beans. Among the adulterants with definite microscopic 
characters found in plain chocolate are wheat flour, maize starch, peanut 
meal, peas, acorns, arrowroot, and cocoa shells. Other adulterants 
which can be identified only by chemical and physical methods are 
foreign fats, mineral make-weights, iron salts, various pigments, and 
coal-tar dyes. 

Sweet Chocolate is prepared by mixing pulverized sugar and flavors 
with the warm chocolate paste before moulding. Vanilla beans (or 
artificial vanillin) and cinnamon are most commonly employed as flavor- 
ing materials, less often cloves, nutmegs, mace, cardamoms, and Peru 
balsam. The adulterants are those noted under plain chocolate. 

Cocoa is obtained by removing a portion of the fat (cocoa butter), 
from warm cocoa mass by pressure and reducing the residue to a powder, 
with or without addition of vanilla flavor. 

Dutch Process, or "Soluble" Cocoa, is cocoa treated with an alkali, 
usually soda or ammonia, to hinder the fat from collecting on the sur- 
face of the beverage prepared from it. The microscopic elements are 
not altered by this treatment. Various starchy preparations and oil- 
seed products such as are noted under chocolate are used as adulterants. 

Cocoa Shells, obtained in large quantities in the manufacture -of 
chocolate and cocoa, are used to some extent in the preparation of a 
beverage, for the manufacture of theobromin, and in mixed cattle foods, 
but are most commonly added to cocoa products or spices as an adulterant. 


The striking histological elements are the cross cells or inner epider- 
mis (Fig. 347, end) of the pericarp, and the underlying tissues of the 
spermoderm, especially the outer epidermis (ep), the numerous narrow 
spiral vessels of the bundles, and the stone, cells. The shells contain a 
higher percentage of crude fiber than the cotyledons, but much less fat, 
starch, and theobromin. 

Compound Cocoa Products. Zipperer gives formulas or analyses of 
seventy-four preparations of chocolate or cocoa with other materials. 
He states, however, that this list is not complete and does not contain 
any of the medicinal chocolates. Some of the ingredients named are 
oatmeal, barley meal, malt, malt extract, wheat flour, potato flour, rice, 
peas, peanuts, acorns, cola nuts, sago, arrowroot, Iceland moss, gum 
Arabic, salep, dried meat, meat extract, peptones, milk powder, plas- 
mon (casein), eggs, saccharin, vanilla, various spices, and inorganic 
salts. Of the products named, only those of vegetable origin can usually 
be identified under the microscope. 

Malt Chocolate and Malt Cocoa more often contain malt extract than 
ground malt, only the latter being distinguishable under the microscope. 

Milk Chocolate, a popular mixture of sweet chocolate and milk powder, 
has no distinctive microscopic characters but "Plasmon Chocolate," 
"Plasmon Cocoa" and various similar preparations show under the 
microscope flakes of casein (Plasmon), which may be tested with reagents 
and dyes. 


See General Bibliography, pp. 671-674: Blyth (5); Fliickiger (n); Greenish 
(14); Hanausek, T. F. (16, 48); Hassall (19); Leach (25); Mace" (26); Meyer, A. 
(28); Moeller (29, 30, 31, 32); Planchon et Collin (34); Schimper (37); Tschirch 
u. Oesterle (40); Villiers et Collin (42); Vogl (43, 45); Weigmann (10). 
Bastings: Starch Grains in the Different Commercial Varieties of Cocoa Beans. 

Amer. Journ. Pharm. 1894, 66, 369. 
Beckurts und Hartwich: Beitrage zur chemischen und pharmakognostischen Kent- 

niss der Cacaobohnen. Arch. Pharm. 1890, 230, 589. 
Bernhard: Ueber Cacao und dessen Praparate. Chem. Ztg. 1888, 12, 445. 1889, 


Bernhard: Ueber die Untersuchung von Cacao und Chocolade. Vers. Schw. Chem. 

12. April, 1890. 
Beythien: Casseler Haferkakao. Jahresber. chem. Unters.-Amt. Dresden, 1900, 10. 
Beythien und Hempel: Chokoladenmehle. Ztschr. Unters. Nahr.-Genussm. 1901 

4 . 23- 

Coster, Hoorn et Mazure: Falsifications observers en Holland. Rev. internat. 
falsificat. 1887-88, 1, 161 . 


Eisner: Rep. analyt. Chem. 1884, 370; 1885, 5, 128, 211. 

Filsinger: Die Untersuchung der Kakaofabrikate auf Gehalt an Kakaoschalen. 
Ztschr. offentl. Chem. 1899, 5, 27. 

Fischer und Grtjnhagen: Untersuchung des Kakao und der Chokolade auf Kakao- 
schalen. Jahresber. chem. Unters.-Amt. Breslau, 1899-1900, 34. 

Fischer: Nachweis von Kakaoschalen. Jahresber. chem. Unters-Amt. Breslau, 
1901-02, 27. 

Hager: Ueber Eichelkakao und Chokolade. Pharm. Ztg. 1888, 33, 511. 

Hanausek, T. F.: Mikroskopische Untersuchung eines hollandischen Eichelcacaos. 
Ztschr. Nahr.-Unters. Hyg. 1887, 1, 247. 

Hanausek, T. F.: Beitrage zur Histochemie der Cacaosamen. Apoth.-Ztg. 1894, 

Hartwich: Ueber die Pigmentzellen des Cacaosamens. Arch. Pharm. 1887, 25, 958. 

Hartwich: Zur Nachweisung fremder Starkemehle in der Chokolade. Chem. Ztg. 

1888, 12, 375. 
Lagerheim: Nachweis von Kakaoschalen. Svensk Kemisk Tidskrift, 1901. 
Lagerheim: Om den mikroskopiska undersokningen af kakao och chokolad. Svensk 

Farmaceutisk Tidskrift 1902, No. 9. 
Legler: Cellulosegehaltes der Kakaobohnen. Rep. analyt. Chem. 1884, 4, 345. 
Legler: Zur mikroskopischen Untersuchung der Cacaobohnen. 14-17 Jahresber. 

Chem. Centralstelle. Dresden, 1886-88. 
Mansfeld: Kakao-Ersatzmittel. Jahresber. Unters. allg. osterr. Apoth.-Ver. 1901-02, 

14, 5- 

Michaelis: Eichelkakao, Eichelchokolade. Pharm. Ztg. 1888, 33, 568. 

Mitscherlich: Der Cacao und Die Chocolade. Berlin, 1859. 
Nothnagel: Untersuchung von Getreide-Kakao. Apoth.-Ztg. 1900, 15, 181. 
Payen: Action de l'iode sur l'amidon du cacao. Jour, pharm. chim. 1862, 41, 367." 
Pennetier: Recherche de la farines de bid dans le chocolat. Jour, pharm. chim. 

1887, 15, 141. 
Pfister: Eine neue Chokoladenfalschung. Forschber. Lebensm. Hyg. Pharmkgn. 

1894, 1, 543- 
Spath: Verfalschung von Cacao. Forschber. Lebensm. Hyg. 1894, 1, 344. 
Thiel: Zur Histologic und Physiologie der Kakaosamen. Forschber. Lebensm. Hyg. 

1894, 1, 219. 
Tichomirow: Ueber die Cacaocultur auf Ceylon. Pharm. Ztschr. f. Russl. 1892, 

31, 260. 

Trojanowsky: Beitr. z. pharmakogn. u. chem. Kenntniss des Cacaos. Inaug.-Diss. 

Dorpat, 1875. 
Tschirch: Untersuchungen der Eichel-Cacaosorten des Handels. Pharm. Ztg. 1886, 

32, 190. 

Tschirch: Ueber den anatomischen Bau des Cacaosamens. Arch. Pharm. 1887, 25, 

Tschirch: Entwicklungsgeschichtliche Studien. Schw. Woch. Chem. Pharm. 1897, 

35, No. 17. 
Welmans: Zur Untersuchung der Kakaofabrikate auf ihren Gehalt an Kakaoschalen. 

Ztschr. offentl. Chem. 1899, 5, 479. 



Zipperer: Ueber den Werth der mikroskopischen Untersuchung bei Bestimmung 
fremden Starkemehls in Chokolade. Chem. Ztg. 1888, 12, 26. 

Zipperer: Beitrage zur Mikrochemie des Thees und des Cacao. VII. Vers. d. freien 
Vereinig. bayr. Chem. Speyer, 1888. 


The seed of Paullinia sorbilis Mart, (order Sapindacea), like coffee 
and the kola nut, contains caffein, and is used in Brazil as a stimulant. 
The dried paste in the form of dark brown, 
sausage-like cylinders, is used in medi- 


The epidermis (Fig. 350) of the spermo- 
derm consists of characteristic palisade cells 

Fig. 350. Guarana (Paidlinia sorbilis). 
Palisade epidermis of spermoderm 
in surface view. (Moeller.) 

Fig. 351. Guarana. Epidermis 
and parenchyma of cotyledon. 

with thick walls. The embryo (Fig. 351) contains small starch grains 
of the allspice type. 


In the commercial product the starch grains are more or less dis- 
torted, owing to the heat employed in drying. Although made from 
the shelled seeds, fragments of the palisade cells are always present. 


See General Bibliography, pp. 671-674: Moeller (32); Vogl (45). 



The seeds of Cola acuminata R. Br. have long been used by the natives 
of West Africa as a stimulant, and have also been introduced into other 
countries as a drug. They contain both caffein and theobromin. The 
commercial product consists of the dried cotyledons, which resemble 
somewhat those of a Spanish chestnut, except that they are of a dark- 
brown color. 

The starch grains are ovate or reniform, up to 30 p long, and have 
an elongated hilum. They are quite like the starch grains of legumes. 

See General Bibliography, pp. 671-674: Vogl (45). 


Tea is the leaf of a shrub (Camellia Thea Link, order Ternslrcemiacece), 
which since time immemorial has been extensively cultivated in China 
and Japan, also more recently in India (Assam), Ceylon, and Java. Its 
culture in South Carolina, although still in the experimental stage, bids 
fair to become an important industry. 

The numerous kinds of tea owe their difference in excellence and 
trade value to differences in the mother plant on the one hand, and to 
the degree of ripeness and method of preparation on the other. As 
a rule only the'leaf buds and the youngest leaves, not the flowers, are 
gathered. What are known in commerce as "flowers" are the gray, 
silky-hairy leaf buds. 

Black and green tea owe their peculiar characters to the method of 
preparation. In the first the chlorophyl is destroyed, in the latter more 
or less preserved. 

Brick tea consists of large leaves not suitable for the preparation of 
black and green tea, ends of branches and other refuse, compressed into 
blocks. It is consumed almost entirely by the Asiatic nomads. 

In China tea designed for export is often perfumed by mixing with 
it fragrant flowers (of Aurantiacece, Osmanthus fragrans, Jasminum, 
Aglaja odorala, Gardenia florida, Chloranthus i neons picuus), which are 
removed after they have wilted. The bottom of the chest is sometimes 
covered with flowers. 

Tea leaves vary more than is commonly stated. They are narrow 



or half as broad as long, pointed or nearly spatulate, serrate or nearly- 
entire, entirely smooth or hairy on the under side, more or less leathery. 
Grown to full maturity they often reach 10 cm., rarely 15 cm., in length, 
but as picked for the market they range from the length of the little finger 
down to the tiny leaves of the buds. 

The following characters are common to all tea leaves: the firm, 
rather thick texture ; the glossy upper surface ; the short stem into which 

Fig. 352. Tea {Camellia Thea). Leaf, 
natural size. (Moeixer.) 

Fig. 353- Tea. Fragment of leaf treated 
■with chloral hydrate, showing tooth, veins, 
crystal rosettes, and stone cells. Somewhat 
enlarged. (Schimper.) 

the base of the leaf tapers; the thick margins, rolled a Jittle towards 
the inner surface, with cartilaginous teeth; the veins which branch from 
the midrib at angles usually greater than 45 , and at some distance from 
the margin form loops uniting adjoining ribs (Fig. 352). The teeth 
(Fig. 353) on the margin of the leaf are shrunken multicellular glands 
which break off readily from old leaves. 

Tea fruit (Fig. 354), consisting of the pericarp with calyx and 
peduncle attached, resembles cloves. The pericarp is globular or trian- 
gular, and has three cells, each containing a single seed. 


Microscopic mounts are prepared after soaking or boiling with water. 
The Upper Epidermis (Fig. 355) consists of small (50 ft) cells with 
L L slightly wavy walls, without stomata or hairs. 



Mesophyl (Fig. 357). The chlorophyl parenchyma adjoining the 
upper epidermis is made up of palisade cells which in surface view are 
circular in outline (Fig. 355, p)\ that adjoining the lower epidermis is 

Fig. 354. Tea Fruit. Natural size. (Winton.) 

Fig. 355. Tea. Upper epidermis 
of leaf and p group of palisade 
cells, seen from below. Xioo. 


spongy, with large star-shaped branching cells (Fig. 356, m). Large 
colorless stone cells or idioblasts (Fig. 357; Fig. 358, st) which are the most 
characteristic elements of the tea leaf, occur here and there in young 
leaves and in considerable numbers in mature leaves. They form as it 
were braces holding apart the epidermal layers. They are extremely 

Fig. 356. Tea. Lower epidermis of leaf with k hair and sp stoma, and m spongy parenchyma 
of mesophyl, seen from below. X160. (Moeller.) 

variable in form and size, but are usually elongated (up to 150 p), 
broadened at the ends, and have simple and forked branches. The 
thickness of the porous walls often exceeds the breadth of the cavity. 

TEA. 455 

Crystal rosettes occur in considerable numbers. 

The Lower Epidermis (Fig. 356) consists of large (70 y) irregular 
cells with wavy contour, among which are numerous large (40-60 /j.) 
broadly elliptical stomata surrounded usually by 3-4 accompanying cells. 

The hairs found on this epidermis, like the idioblasts, are highly 
characteristic. On old leaves they occur sparingly or not at all, and 
their scars, owing to the growth of the neighboring cells, are also seldom 

Fi°. 357- Tea. Cross section of leaf showing epidermal cells, palisade cells, fibro-vascular 
bundle, spongy parenchyma with crystal rosettes, and large stone cell. (Mez.) 

evident. On young leaves, however, they form a dense pubescence. 
They are unicellular, thick-walled, often over 1 mm. long, and are usually 
geniculate near the base, thus causing them to lie flat on the surface of 
the leaf. 


After heating to boiling in water the leaves may be spread out and 
examined.. Even quite small fragments can be recognized by their tex- 
ture, venation, dentation and other macroscopic characters. The chief 
microscopic elements of value in diagnosis are the epidermal cells, the 
geniculate hairs and the idioblasts. 

Tea Adulteration. Gross adulteration, such as the addition of 
exhausted leaves, foreign leaves and mineral make-weights, is seldom 
practiced at the present time. Low-grade teas often contain tea stems, 

45 6 


and sometimes tea fruit. Facing, although objectionable, is not usually 
regarded as an adulteration. 1 

Exhausted Tea. Leaves which have been used once for the prepara* 
tion of the beverage are said to be collected in England, Russia, and 
China, impregnated with catechu or caramel, and prepared in imitation 
of genuine tea. This worthless product has the same microscopic 
appearance as genuine tea, but can often be detected by chemical means, 

FlG. 358. Tea. Tissues of leaf isolated by warming in alkali and squeezing with coyer 
glass, g spiral vessels of nerves; p chlorophyl parenchyma; st stone cells; h hairs. 
X 1 60. (Moeller.) 

particularly determinations of hot -water extract, tannin, total and water- 
soluble ash. 

Tea Fruit. Soltsien has reported several cases of adulteration with 
the dried fruit. Winton found in a sample sold in Connecticut 11.5 per 
cent of this adulterant. 

Tea Stems. Tea often contains a small amount of stems as an acci- 
dental impurity. A considerable amount indicates adulteration. 

"Lie Tea" consists of tea leaves and other refuse made into lumps 
with starch-paste. These lumps fall apart on spaking in water. 

Mineral Make-weights, including soapstone, gypsum, iron dust, and 
sand, afe detected by chemical analysis. j ^~ 

Facing. A large part of the green tea and much of the black tea is. 
" faced, " or coated, to impart a gloss and an attractive color. Among 
the materials employed in facing green tea are Prussian blue (ferric ferro- 

1 Except for facing, the tea on the American market at the present time is seldom adul- 
terated (A. L. W.). 

TEA. 457 

cyanide, ultramarine, indigo, turmeric, soapstone, and gypsum. Black 
tea is frequently coated with plumbago. 

The following microchemical tests for the detection of facing are 
from the third edition of Leach's Food Inspection and Analysis, p. 

375 : 

" The most delicate test for facing is to examine under the microscope 
or lens, the dust obtained by sifting the leaves or the sediment obtained 
after shaking with water. Plumbago appears glossy black, soapstone 
gray, gypsum white, Prussian blue, ultramarine and indigo shades of 
blue, turmeric yellow. Prussian blue is decolorized by sodium 
hydroxide solution. Ultramarine is not affected by alkali, but is de- 
colorized by hydrochloric acid. Indigo is not decolorized by either 

Foreign Leaves, widely different in form and size from the tea leaf, 
can be used as adulterants provided they are not too hairy or too strongly 
scented. The adulterator selects not only leaves which outwardly resemble 
tea leaves, of which there are an abundance, but, trusting to the indif- 
ference of the consumer, uses leaves of the oak, poplar, maple, plane tree,, 
and others, which do not have the slightest resemblance to tea leaves, and 
which the layman, if he would take the trouble to spread out the spent 
leaves, would at once either identify, or at least recognize as foreign. 
Most of these leaves on close inspection show peculiarities in texture, 
venation, dentation, and other characters, thus rendering microscopic 
examination superfluous. Only in cases where absolute proof is required,., 
especially when the leaves are in fragments, is it necessary to resort 
to microscopic examination. The leaves described on pp. 458-483 do not 
include all that may be used as adulterants of tea, but only those which 
resemble tea leaves in form or else are most commonly used either as 
adulterants or substitutes. 


See General Bibliography, pp. 671-674: Bell (1); Berg (3); Blyth (5); Greenish 
(14); Hanausek, T. F. (10, 16); Hassall (19); Leach (25); Mace" (26); Moeller (29, 
30, 31, 32); Planchon et Collin (34); Schimper (37); Tschirch u. Oesterle (40); Villiers 
et Collin (42); Vogl (43, 45). 
Anonymous: Teefalschung in Russland. Schw. Woch. Chem. Pharm. 1892, 142. 

Weidenroschenblatter als Tee. Pharm. Ztg. Russland, 1875. 
Batalin: Ein neues Ersatzmittel fiir Tee. Indbltt. 1888, 25, No. 14, 59. 
Borkowski: Du faux the - russe. Rev. int. falsific. 1896, 9, 131. 
Brunotte: De la determination histologique des falsifications du The". These E*c. de 

Ph. de Nancy, 1883. 


Collin: Du the" chinois et de quelques-une de ses succe'dane's. Journ. pharm. chim.. 

1900, 11, 15. 
Dragendoref: Falschungen in Russland. P. Tr. (3), 1048. 
Hanausek, T. F. . Ueber den kaukasischen Tee, nebst Beitragen zur vergleichenden 

Anatomie der Yacciniumblatter. Chem. Ztg. 1897, 21, 115. 
Lorenz: Tee aus Blattern der kaukasischen Preiselbeere. Apoth. Ztg. 1902, 16, 

Lubelski: Ueber Kultur und Falschungen des Tees. Rep. Fals. intern. 3, 88. 
Medhurst: Consular Report. Drog. Ztg. o u. Jahresber. Fortschr. Pharm. 1879, 43. 
Meyer, Ad.: Anat. charakt. off. Blatter u. Krauter. Halle, 1882. 
Molisch: Histochemie. Jena, 1891. 
Netolitzky: Dikotyledonblatter. Wien, 1905. 

Riche et Collin: Falsification du the en Chine. Jour, pharm. chim. 1890, 21, 6. 
Riche: Gefalschter Tee. Chem. Ztg. 1899, 13, Rep. 19, 155. 
Soltsien: Verfalschung des Tees mit Teefrttchten. Pharm. Ztg. 1894, 39, 347. Ztschr 

"offentl. Chem. 1902, 8, 254. 
Stackmann: Kaukasischer Tee aus Kutais. Ztschr. anal. Chem. 1895, 34, 49. 
Tichomirow : Zur Frage iiber die Expertise von gef alschtem und gebrauchtem Tee 

Pharm. Ztschr. f. Russl. 1890, 29, No. 29-40. 
Winton: The Adulteration of Tea with Tea Fruit. Conn. Agr. Exp. Stat. Rep. 1901, 



The leaves of gromwell (Lithospermum officinale L., order Bor- 
raginacea) are entire, sessile, up to 8 cm. long and scarcely 15 mm. broad 
(Fig. 359). The veins are few, form sharp angles with 
the midrib, and near the margins anastomose, forming 
flattened loops. The leaves have rough hairs on both 
sides which are evident on passing the fingers from tip 
to base, and are seen under a lens to spring from rounded 

The Epidermis on the upper side (Fig. 360) consists 

of irregularly polygonal cells, on the lower side (Fig. 

361) of thin- walled cells with more or less wavy contour. 

The stiff, somewhat curved, sharp-pointed, warty hairs 

are 600 /1 or more long, and are often 40 /a broad at the 

base. They have thickened walls, and contain cysto- 

liths or concretions of calcium carbonate, which are 

Fig. 359. Gromwell especially well developed in the retort-shaped bases. 

family"' 1 ™"*!, Cystoliths are also present in the cells of the upper 

natural size, epidermis. Small stomata, 30 u long, occur in the upper 

(MOELLEE.) .... r ° -^ r 

epidermis in great numbers. 
Gromwell leaves prepared like black tea are sold unmixed in 


45 9 

* — 

Fig. 360. Gromwell. Upper epidermis of Fig. 361. Gromwell. Lower 
leaf. X160. (Moellek.) epidermis of leaf. X160. 


Bohemia, and a similar product, containing the fruits as well 
as the leaves, was at one time made in Styria. The chief 
characters are the thin texture of the leaf and the rough hairs. 


The narrow-leaved willow herb (Epilobium angusti- 
jolium L., Chamanerium angustifolium Scop., order Oeno- 
therea) has lanceolate, sharp-pointed leaves which are sessile 
or with short petioles, entire or sparingly toothed (Fig. 362). 
The numerous veins are at nearly right angles to the mid- 
rib, and anastomose at the border in short loops. 

Upper Epidermis. (Fig. 363.) The cells are about 50 pt 
broad, with slightly wavy, thick, here and there knotty- 
thickened walls. Stomata are absent, but water stomata 
occur near the apex.. 

Lower Epidermis. (Fig. 364.) The cells have thinner 
and wavier walls than those of the upper epidermis, and 
are covered by a wrinkled cuticle with a finely granular de- 
posit of wax. The numerous stomata are about 30 fi long 
and 20 ji broad. Under each tooth is a water stomata. 
Young leaves bear along the veins unicellular, blunt, thin- fig. 3*62. Willow 
walled, striated, mostly crooked hairs (Fig. 365). ^ erb (EpUo- 

The Mesophyl contains numerous raphides (Fig. 364) folium). Leaf, 
accompanying the bundles. (MoeIleI!) 6 ' 



Leaves of this species are used in Russia as a substitute for or an 
adulterant of tea. 

The chief characters are the thin, entire or sparingly toothed leaves with 

Fig. 363. Willow Herb. Upper epidermis Fig. 364. Willow Herb. Lower epidermis of 
of leaf. X160. (Moeller.) leaf, also K raphides cell and ch chloro- 

phyl cells. X 160. (Moeller.) 

Fig. 365. Willow Herb. Epidermis of young leaf with hairs. (Moeller.) 

numerous veins nearly at right angles to the midrib, the striated lower 
epidermis with wavy walls and small stomata, and the raphides. 



The leaves of the hairy willow herb (Epilobium hirsutum L.) are 
clasping, lanceolate, wavy-toothed, with a smooth upper and a hairy 
lower surface (Fig. 366). The pronounced branching veins form loops 
near the margins. The epidermal cells are similar to those of the foregoing 

Fig. 366. Hairy Willow Herb 
(Epilobium hirsutum). Leaf, 
natural size. (Moeller.) 

Fig. 367. Hairy Willow Herb. 
Epidermis of leaf with hair. 

Fig. 368. Willow (5a- 
lix sp.). Leaf, natu- 
ral size. (Moeller.) 

species, but the hairs are smooth, and many of them have characteristic 
globular heads (Fig. 367), Pointed hairs, much longer than the preceding, 
are also present, being especially abundant at the margins. 


The willows (Salix) have long, pointed, entire or toothed, smooth or 
hairy, short -petioled, rather thick leaves. They resemble tea leaves, but 
the veins are more numerous, and they do not form loops at the margin 
(Fig. 368). 


The Epidermis (Fig. 369) is much the same on both surfaces, but on 
the upper surface is strongly cuticularized and striated. The cells are 
small, sharply polygonal or very slightly sinuous in outline. Numerous 
small (25 n) stomata, often with two accompanying cells, occur on the 
lower epidermis. Both epidermal layers are clothed with hairs, which 
resemble those of tea, but are not geniculate. The hairs of young leaves 


Fig. 369. Willow. A upper epidermis of leaf. B lower epidermis with hairs and stomata. 

X160. (Moeller.) 

are thin-walled, while those of full-grown leaves often have walls so strongly 
thickened as to obliterate the cavities. The marginal teeth end in multi- 
cellular glands. 

The Mesophyl contains numerous oxalate rosettes and also simple 

Willow leaves, according to the English consul Medhurst, are collected 
in China in great quantities, prepared like tea, and mixed with this product 
to the extent of 20 per cent. (See Bibliography of Tea, p. 458.) 

This leaf can usually be distinguished from tea by its venation. The 
characteristic microscopic elements are the thin-walled hairs and the 
four-celled stomata. The crystal rosettes of both leaves are similar, 
but simple crystals are not found in tea. 


The leaflets of the odd-pinnate leaves of the ash (Fraxinus sp., order 
Oleacea), are similar to tea leaves in general outline, although they are 
often broader and more sharply toothed, and, furthermore, have very 
different venation (Fig. 370). The numerous veins, which in young 
leaves are especially well marked, anastomose near the margin, and from 



the loops arise short veinlets which usually end in the notches between 
the teeth. 

Epidermis (Fig. 371). On both sides the 
cells have sinuous walls. The lower epidermis 
bears numerous large stomata (30-40 /*), with- 
out accompanying cells. Highly characteristic 
are the cuticular thickenings or folds at the 
poles of the stomata, which give the latter a 
horned appearance. Glandular hairs with 
wheel-like multicellular heads, also short one- 
to two-celled hairs with striated cuticle, occur 
on the lower epidermis. 

Mesocarp crystals are absent. 

The indescribable but highly characteristic 
thin sinuous walls of the upper epidermis, the 
elongated and horned stomata and the glandular 
hairs are positive means of distinction from tea. 


The European rowan or mountain ash (Sor- 
bus Aucuparia L., Pyrus Aucuparia Gaertn., 
order Rosacea), is often cultivated because of its 
scarlet berries. The odd-pinnate leaves are 
pubescent when young, nearly smooth when 
old (Fig. 372). The leaflets are lanceolate and 
irregularly serrate. The veins pass into the teeth without forming loops 
A B 

Fig. 370. Ash (Fraxtnus 
sp.) . Leaflet, natural size. 

Fig. 371. Ash. A upper epidermis of leaf. B lower epidermis with sp stomata and ( 
glandular hair. X160. (Moeller.) 

The Epidermis (Fig. 373) of the under side is like that of the upper 



side except that stomata are present. In outline the cells are partly 
polygonal, partly sinuous. Delicate striations mark the cuticle. The 
long, unicellular, sinuous hairs with rounded bases are characteristic. 

^^^^^r "^^^^ 

Fig. 372. Rowan (Sorbus Aucuparid). 
Leaf, natural size. (Moeller.) 

Fig. 373. Rowan. Epidermis of leaf with 
stoma, and hair. (Moeller.) 


The white and black mulberry trees (Moms alba L. and Morus nigra L., 
order Moracea), natives of Asia, are grown for their leaves in Southern 
Europe and other silk-producing regions, and elsewhere for their fruit 
or shade. 

The leaves of the white mulberry are light green, ovate heart-shaped, 
unequal at the base, long-petioled, nearly smooth on the upper side (Fig. 
374) ; those of the black species are dark green, heart-shaped with taper- 
ing point, regular at the base, short-petioled, with rough hairs on the 
upper side. Soft hairs occur sparingly on the under surface of both species 



Epidermis (Figs. 375 and 376). On the upper side the cells are 
polygonal, while those of the under side are unusually small and have sin- 



m 1 





FlG. 374. Mulberry (Morusalba). Leaf, natural size. (Moelxek.) 

uous walls. Stomata are present only on the under side. Large epidermal 
cells containing cystoliths occur on both sides, the cells about them 
forming rosettes. The hairs are unicellular, very long, thin-walled, 

Fig. 375. 

Mulberry. Section of lower epidermis of leaf showing stoma and cystolith. 

smooth, more or ess sinuous, but quite rigid. Glandular hairs with a 
unicellular base and multicellular head are also present. 
The Mesophyl contains crystal rosettes. 



Leaves of the coffee tree (Coffea Arabica L., order Rubiacea), like the 
seeds, contain caffein, although in smaller amount. They are used as 

Fig. 376. Mulberry. Upper epidermis of leaf (above) ;• lower Fig. 377. Coffee {Coffea 

epidermis with hairs, stomata and cystolith (below). Arabica). Leaf, natural 

(MOELLEK.) Size. (MoELLER.) 

A £ 

Fig. 378. Coffee. A upper epidermis of leaf. B lower epidermis. X160. (Moeller.). 

substitutes for tea in coffee-growing countries, and their introduction 
into Europe has been suggested. 



The leathery, smooth, shining, dark-green leaves are elliptical, taper- 
ing gradually to a point at the apex and into the short stem at the base 
(Fig. 377). Teeth are not present. The veins form sharp angles with 
the midrib, and anastomose with the formation of pronounced curves. 

Epidermis (Fig. 378). The cells on both sides have sinuous walls. 
On the under side large stomata (25-45 ft) to the number of 60 per sq. 
mm. are distributed in a peculiar manner among the epidermal cells. 

The Mesophyl contains crystal sand. 

The leaf is prepared for use by roasting, "and is never rolled like tea. 


The camellia (Camellia Japonica L., order Temstroemiacem) grows 
native in Japan, and is cultivated as a greenhouse plant in Europe and 

America. It is closely related to tea, but the 
leaves (Fig. 379) contain no caffein. On care- 
ful examination geniculate hairs similar to 
those of tea may be found on the young 
leaves, but only on the margins. These soon 
drop off, leaving the mature leaf smooth and lus- 
trous. The leaf is similar to the tea leaf in form 
and venation, but is larger, broader and thicker. 

Fig. 379. Camellia {Camellia 
Japonica). Leaf, natural 
size. (Moeixer.) 

Fig. 380. Camellia. Epidermis of leaf in cross. 
section. (Moeller.) 

Epidermis (Figs. 380 and 381). Cross-sections show that the strongly 
thickened and cuticularized outer walls have wart-like projections on 
their inner surfaces. In surface view the cells show broad pores, and 
in consequence of the projections are often very irregular in form. The 
stomata are often nearly circular, and occur only on the lower epidermis. 

4 68 


The Mesophyl contains idioblasts and oxalate crystals similar to 
those of tea. 

Fig. 381. Camellia. Lower epidermis of leaf. (Moeller.) 

The leaves are said to be used as an adulterant 
of tea, although poorly suited for the purpose. 
The thick-walled epidermis is characteristic. 


Leaves of the sweet cherry (Primus avium L., 
order Rosacea?) are seldom over 10 cm. long, 
about 5 cm. broad, oblong-ovate, taper-pointed, 
petioled, with numerous teeth on the margin, 
each with a small gland (Fig. 382). On one or 
both sides of the petiole is a brown, glistening 

Fig. 382. Cherry (Primus 
avium) . Leaf, natural size. 

Fig. 383. Cherry. Upper epidermis of leaf. 
X 300. (Moeixer.) 


The Upper Epidermis (Fig. 383) is made up of irregularly polygonal 
cells averaging 30 //, with a very delicate, finely striated cuticle. Along 
the veins are a few unicellular, dagger-shaped hairs about 600 n long 
and the same size at the base as the epidermal cells. 

The Lower Epidermis (Fig. 384) consists of delicate cells with sinuous 

FlG. 384. Cherry. Lower epidermis of leaf. X300. (Moeller.) 

walls, numerous circular or elliptical stomata and hairs of the same type 
as those on the upper epidermis, but longer and thinner-walled. 

Noteworthy are the small oxalate rosettes occurring here and there 
in small epidermal cells. 

The Mesophyl contains numerous oxalate rosettes, 
and accompanying the bundles, simple crystals. 

The leaves of the sour cherry (P. Cerasus L.) are 
stiff, lustrous, and apparently smooth. 


The obovate or elliptical-lanceolate leaves of the sloe 
or black thorn (Prunus spinosa L.) resemble somewhat 
tea leaves. Their borders are sharply and irregularly FlG g * sloe 
toothed (Fig. 38O. The veins form sharp angles with (Prunus spi- 

.,.,,, , ,. . , , . nosa). Leaf, 

the midrib, and do not form distinct loops at the margin. natural size. 

The Upper Epidermis (Fig. 386) consists of thick- ( MoELI - EE -) 
walled, polygonal cells with delicate striations, through which here and 
there shimmer simple crystals and rosettes. 



The Lower Epidermis (Fig. 387) is more delicate than the upper, 
and the cuticle is striated only in places. The cells have slightly sinuous 

Fig. 386. Sloe. Upper epidermis of 
leaf. X160. (Moellee.) 

Fig. 387. Sloe. Lower epidermis of leaf, 
seen from below. The crystal cells are 
not in the epidermis but in the meso- 
phyl, accompanying the fibro-vascular 
bundles. X160. (Moellee.) 

walls, and are interspersed with numerous small (25 p) stomata in groups, 

some of which have horns like those of the ash leaf. 

The Mesophyl contains numerous crystal cells with rosettes or simple 

crystals of considerable size. Accompanying the fibro-vascular bundles, 

particularly on the under side, are crystal fibers, some of which on remov- 
ing the epidermis adhere to it. Unicellular, rather thick- 
walled, often sinuous hairs are found along the veins 
and on the margins. 


The leaflets of the odd-pinnate leaves of the rose 
(Rosa canina L., and other species) are easily distin- 
guished from tea leaves by their greater breadth, rounded 
base, dense and sharp serration, and vein-meshes (Fig. 
Fig. 388 Rose (Rosa ,gg). Each tooth ends in a multicellular gland. 

canina). Leaf- . 

let, natural size. The Epidermis (Fig. 389) is similar to that of the 

(Moellee.) ^oe, but the cuticle is smooth, and the walls are in 

many parts knotty and thickened. Many of the cells, along the veins, 

are filled with a homogeneous brown substance. The stomata on the 



lower epidermis are rounded elliptical, of considerable size (35-40 /«) 
without accompanying cells. 

Tig. 389. Rose. A Upper epidermis of leaf. B lower epidermis seen from below; also 
crystals from mesophyl. X160. (Moeller.) 


The wood strawberry (Fragaria vesca L., order Rosacea), has long- 
petioled, trifoliate leaves with coarsely serrate leaflets irregular at the 

Fig. 390. Strawberry (Fragaria vesca). Leaflet, natural size. (Moeller.) 

base and hairy underneath (Fig. 390). There are as many veins as 
teeth, each vein ending in a tooth. 

The Epidermis (Figs. 391 and 392) of both sides is similar, except that 


the cells on the under side have thinner walls, which are sinuous. Two 

FIG. 391. Strawberry. Upper epidermis of leaf. (Moeller.) 

Fig. 392. Strawberry. Lower epidermis of leaf. (Moeller.) 

forms of hairs occur on both surfaces: (1) very long, unicellular, rigid 



and mostly straight, with thick porous base, and (2) multicellular, with 
globular heads, the thin walls swelling greatly in alkali. 

The Mesophyl contains great numbers of large simple crystals. 


Meadowsweet (Spircea Ulmaria L., order Rosacea) grows wild in 
Europe and Asia and is also cultivated for its flowers, which were once 
used in medicine. 

The interruptedly pinnate leaves have irregularly pointed, ovate side 

F 10 - 393- Meadowsweet (Spiraa Ulmaria). Leaflet, natural size. (Moellee.) 

leaflets, and 3-5 lobed end leaflets (Fig. 393). Both forms are com- 
pbundly serrate. The ribs and veins are prominent on the under surface, 
and bear rough hairs. The veins anastomose some distance from the 
edge and send off branches into the teeth. 


The Epidermis (Figs. 394 and 395) of both sides is delicate, and not 

Fig. 394. Meadowsweet. Upper epidermis of leaf. (Moeller.) 

easily separated from the leaf. On the upper 
side the walls are slightly wavy, on the under 
side deeply wavy. Stomata occur only on the 
under side, hairs of three forms on both sides, 
but chiefly along the veins on the under side. 
The hairs on the body of the leaf are mostly 
unicellular, dagger-shaped, often sinuous, with 

Fig. 395. Meadowsweet. Lower Fie. 396. Meadowsweet. G landular hairs of leaf. 
epidermis of leaf. (Moei.ler.) (Moeixer.) 



deeply-planted, rounded-angular base. On the veins, glandular hairs, 
some with short jointed stems, others with long two-rowed stems, 
predominate (Fig. 396). The heads of both 
forms are multicellular and globular. 

The Mesophyl contains a few crystal rosettes 
chiefly along the midrib. 


In Japan the odd-pinnate leaves of Wistaria ' 
Sinensis DC. (Kraunhia floribunda Taubert, 
order Papilipnacece) are used as an adulterant 
of tea. The leaflets are ovate-lanceolate, entire, 
slightly plaited at the margins, not petioled 
(Fig. 397). The prominent veins form near 
the margin indistinct loops. 

Fig. 397. Wistaria {Wistaria 
Sinensis) Leaflet natura. 


Fig. 398. Wistaria. Upper epidermis of leaf Fig. 399. Wistaria. Lower epidermis of 
in cross section and surface view. (Moeller.) leaf. (Moeller.) 

The Epidermis (Figs. 398 and 399) consists of cells with thin wavy 
walls and curious hairs, made up of a short basal cell, a short thick-walled 



middle cell and a long, straight or sickle-shaped, thin walled, pointed end 

cell. Stomata occur only on the under 

Simple crystals accompany the bundles. 

Fig. 400. Hydrangea {Hydrangea 
Hortensia). Leaf, natural size. 

Fig. 401. Hydrangea. Epidermis of leaf 
with hairs. (Moeixer.) 


This shrub (Hydrangea Hortensia DC, order Saxijragacea), is a native 
of Japan and northern China. In Japan the leaves are employed as a tea 

Fig. 402. Hydrangea. Lower epidermis of leaf. (Moeller.) 

substitute under the name of "Ama-cha." x They reach the size of the 

1 Kellner; Hayakawa, and Kamoshita: Mittlg. d. deutsch Ges. f. Nat. u. Volkerk. Os- 
tasiens. IV. 



hand and are short-petioled, pointed-ovate, entire below, unequally 
dentate above (Fig. 400). The veins extend in gentle curves almost 
to the margin, where they anastomose and send off branches into 
the teeth. 

Epidermis (Figs. 401 and 402). The cells are polygonal or sinuous 
in outline. Unicellular hairs with rounded base and apex occur only 
along the veins. 

The Mesophyl contains raphides. 


The leaves of most maples are palmately lobed, but in the ash-leaved 
species {Acer Negundo L., or Negundo fraxinifolium Nutt, order Acer- 
acece) they are odd-pinnate, somewhat resembling 
tea. Each leaflet is short-petioled, ovate-lanceo- 
late, coarsely but sparingly toothed (Fig. 403). 
The veins form indistinct loops near the margin. 
To the naked eye they appear smooth, but under 
the lens they are hairy on the margins. 

Epidermis (Fig. 404). The cells are irregu- 
larly polygonal. Stomata occur on both surfaces, 
also: (1) unicellular smooth or warty hairs with 
rounded base, blunt point and slightly thickened 
walls, swelling and becoming stratified with 
alkali; (2) glandular hairs with 2-3 celled stem 
and unusually large head. 

The Mesophyl contains large simple crystals. 


Oak leaves of different species are widely 
different in form and size. The description 
here given applies to two European species 
(Quercus pedunculated Ehrh., and Q. sessiliflora 
Sm., order Fagacece). 

Epidermis (Figs. 406 and 407). Polygonal 
cells and 2-3 celled hairs with rounded apex 
and, often, broad base, are found on both surfaces; stomata only on 
the lower surface. 

Fig. 403. Ash-leafed Maple 
{Acer Negundo). Leaf, 
natural size. (Moeller.) 



Fig. 404. Ash-leafed Maple. Upper epidermis of leaf. (Moeller.) 

Mesophyl. The bundles are accom- 
panied by simple crystals. 


According to Kellner 1 the leaves of 
"Fagi-Kadsura-Akebi" (Akebia quinata 
(Thbg.) Decaisne, order Lardizabalacem), 
a perennial climbing plant, are used in 
Japan as a tea substitute. The plant is 
cultivated in the Occident for ornament. 

The obovate, entire, petioled leaflets 
are smooth, with four or less deli- 
cate veins, forming broad loops (Fig. 

Epidermis (Figs. 409 and 410). On 
the upper side the cells are large, with 
pronounced wavy walls; on the under side 
they are smaller and more nearly poly- 
gonal, and usually have papillae similar 

^r^ttiuo^i^ to *** ° f coc ° a leaves > althou § h not so 

1 Loc. cit. 


strongly thickened. These papillae are not found on the four or more 
cells adjoining the stomata. 

Fig. 406. Oak. Upper epidermis of leaf. (Moeixer.) 

Fig. 407. Oak. Lower epidermis of leaf. (Moeixer.) Fig. 408. Akebia (Akebia 

quinala). Leaflet, natural 
size. (Moeixer.) 

Fig. 409. Akebia. Upper epidermis of leaf. (Moeixer.) 



Fig. 410. Akebia. Lower epidermis of leaf. (Moellek.) 

Mesophyl. A few simple crystals accompany the bundles. 


Of the numerous species of blueberries, the common European 
species {Vaccinium Myrtillus L., order Ericacem) is here described. The 
leaves are ovate, finely serrate and lustrous (Fig. 411). The veins are not 

Fig. 411. European Blueberry 
{Vaccinium Myrtillus). Leaf, 
natural size. (Moeller.) 

Fig. 412. European Blueberry. Margin of 
leaf with teeth, under a lens. (Moeller.) 

prominent, but form a beautiful network. Under a lens each tooth is 
seen to end in a stalked gland (Fig. 412). 

Epidermis (Figs. 413 and 414). On the upper side stomata are absent, 
and the cells are either isodiametric, deeply sinuous, or, along the veins, 
elongated, slightly sinuous. Unicellular, warty, sickle-shaped hairs and 
multicellular glandular hairs like those of the teeth, accompany the elon- 
gated cells. The lower epidermis consists of deeply sinuous cells, stomata 



with 4-5 accompanying cells, and glandular hairs like those described. 
Hanausek finds that if the margin is boiled with dilute potash, numerous 

Flo. 413. European Blueberry. Upper epidermis of leaf. fMoELLER.) 

fine crystals, soluble in acetic acid, separate from the glandular 

Mesophyl. Simple crystals occur in crystal fibers or singly. 


In Russia the leaves of V actinium Arctostaphylos L. are prepared 
like tea. Leaves of this species are considerably larger than the preced- 
ing species, leathery, finely serrate, appearing smooth to the naked eye. 
The veins on the under side are prominent, forming indistinct loops 
distant from the margin. Under the lens hairs are evident along these 
veins, also a glandular hair on each tooth. 

Epidermis (Figs. 415 and 416). The upper epidermal cells are poly- 
gonal, thick- walled, often porous, with a striated cuticle; those of the 


lower epidermis are sinuous, with thin walls. Unicellular, thick-walled 

Fig. 414. European Blueberry. Lower epidermis of leaf. (Moeller.) 

Fig. 415. Caucasian Tea {Vaccinium Fig. 416. Caucasian Tea. Lower epidermis 

Arctostaphylos). Upper epidermis of leaf. (Moeller.) 

of leaf. (Moeller.) 

warty hairs occur on both surfaces, but in the greatest numbers along the 
midrib on the under side. Glandular hairs occur not only on the teeth 



but also, sparingly, on the surface. Hanausek notes a third form, 
designated "bladder hairs. " 

Mesophyl. Crystal rosettes and simple crystals are present, the latter 
along the bundles. 


Mate", the only substitute for tea containing caffein, is described 
below. Leaves of the following plants are or have been used as sub- 
stitutes in the regions named: 

North America: Species of Ledum (Labrador Tea); Ceanothus 
Americanus L. (New Jersey Tea); species of Monarda (Oswego Tea); 
Chenopodium ambrosioides L. (Mexican Tea). 

South America: Lantana pseudothea, Stachytarpheta Jamaicensis, 
Psoralia glandula, Myrtus Ugni, Alstonia theceformis, Capraria biflora, 
Angrecum fragrans, and Eritrichium gnaphaloides. 

China: Sageretia theezans. 

Australia: Species Myrtacece. 


Mate, Paraguay tea, or Jesuit tea, is prepared 
from the leaves of Ilex Paraguariensis St. Hil. 
(order Aquijoliacece), a small tree growing in South 
America. The leafy branches are cut from the tree 
and dried by artificial heat, after which the leaves 
are stripped off and ground to a coarse powder. 
In this form it is placed on the market as a sub- 
stitute for tea. It is quite commonly used in South 
America, but not to any extent in other regions, 
notwithstanding repeated efforts of promoters. The 
product contains as high as 20 per cent of tannin 
and a considerable amount of caffein (0.5-0.9 per 

The leaves are up to 13 cm. or more long and 4 
cm. broad, ovate or nearly spatulate, tapering to the 
short petiole, blunt or rounded at the apex. They 
are dentate, smooth but only slightly lustrous, and 
leathery (Fig. 417). The veins form sharp loops at some distance from 
the margin. The secondary veins are also distinct. 

Fig. 417. Mat<5 {Ilex 
Paraguariensis). Leaf, 
natural size. (Moel- 




Epidermis (Figs. 418 and 419). On both sides the cells are more or 
less polygonal, with striated cuticle. Along the veins they are arranged 

Fig. 418. Male\ Upper epidermis of leaf, from one of the veins. (Moeller.) 

side by side in rows. Numerous stomata, larger than the surrounding 
cells, occur on the lower epidermis. 

The Mesophyl contains oxalate rosettes. Thick strands of fibers 
accompany the bundles. 

FIG. 419. Mati. Lower epidermis of leaf. (Moeixek.) 


See General Bibliography, pp. 671-674: Moeller (30, 31, 32); Planchon et Collin 
(34); Tschirch u. Oesterle (40); Vogl (44). 

Cadoe: Anatomische Untersuchungen der Matebiatter unter Beriicksichtigung ihres 
Gehaltes an Tern. Bot. Centralbl. 1900. 



Collin: Du mate" ou the" du Paraguay. Journ. pharm. chim., 1891. 

Collin: Journ. pharm. 1886. 

Doublet: Le mate. Paris, 7885. 

Loesener: Beitrage zur Kenntnis der Matepflanzen. Ber. deutsch. pharm. Ges. 

1896. Notizbl. d. konigl. Bot. Gartens u. Museums in Berlin, 1897. Verh. d. 

bot. Ver. d. Provinz Brandenburg, 1891. 
Neger und Vanino: Der Paraguay-Tee. Stuttgart, 1903. 
Polenske u. Busse: Beitrage zur Kenntnis der Matesorten des Handels. Arb. des 

kaiserl. Gesundheitsamtes, 1898. 


The leaves of the coca shrub (Erythroxylon Coca Lam., order Ery- 
throxylacea) have been chewed by South American natives for genera- 
tions. Of late years they have been in demand for 
the preparation of cocaine, the well-known an- 
aesthetic. The full-grown leaves (Fig. 420) are 6-8 
cm. long, half as broad, ovate, blunt or rounded 
at the apex, short-petioled, smooth, light green 
beneath. The midrib extended beyond the apex 
forms a short prickle. The veins anastomose some 
distance from the entire but slightly revolute mar- 
gin, while the veinlets form a delicate network 
with wide meshes. On holding a leaf to the light, 
two slender curved ribs running each side of the 
midrib from base to apex are evident. These are 
not at all connected with the venation, but serve 
to stiffen the leaf. 


Fig. 420. Coca (Ery- 
throxylonCoca). Leaf, 
natural size. (Moel- 

Cross sections show a small-celled upper epi- 
dermis with a thin cuticle, a single layer of mod- 
erately elongated palisade cells, a loose spongy parenchyma pierced by 
vascular bundles, and finally the lower epidermis of curiously humped 
cells (Fig. 421). 

The Upper Epidermis (Fig. 422) consists of somewhat thick, polygonal 
cells with a finely granular cuticle. 

The Lower Epidermis (Fig. 423) has walls similar to those of the upper, 
but somewhat wavy. In the middle of each is a hump-like papilla which 



in surface view appears like a circle with double contour. The stomata 
are very small (20-30 (i), and are flanked by two accompanying cells 
without papillae. 

Mesophyl. Monoclinic crystals are abundant, particularly on the 
under side of the bundles. In the false ribs the subepidermal tissue is 
not spongy but collenchymatous, thus strengthening the leaf. 

The venation and the lower epidermis are characteristic. 

Fig. 421. Coca. Leaf in cross section, epa upper epidermis; p palisade cells; m 
spongy parenchyma with bundle and K crystal cell; epi lower epidermis with sp 
stoma. X160. (Moeller.) 

r— J» 

Fig. 422. Coca. Upper epidermis of 
leaf and p palisade cells, from below. 
X 160. (MOELLER.) 

Fig. 423. Coca. Lower epidermis of leaf 
with sp stoma. X160. (Moeller.) 


See General Bibliography, pp. 671-674: Koch, L. (22); Moeller (30,31,32); Plan- 
chon und Collin (34); Tschirch u. Oesterle (40); Vogl (44). 
Hartwich: Beitr. z. Kenntnis d. Cocablatter. Arch. d. Pharm. 1903. 
Hartwich: Beitr. z. Kenntnis d. Cocablatter. Pharm. Praxis, 1904. 
Hartwich: "Coca" in Realenzykl. d. ges. Pharm. 2. Aufl., III. 1904. 
Moeller: Die Falten des Cocablattes. Pharm. Post, 1891. 
Nevinny: Das Cocablatt. Wien, 1866. 



Fig. 424. Tobacco (Nicotiana Tabacum). Small leaf, natural size. (MoELLEE.) 




Two species (Nicotiana Tabacum L., N. rustica L., order Solanacea) 
and their varieties, yield the tobacco of commerce. These plants, natives 
of the New World, were first introduced into Europe in 1586 by Francis 

Tobacco leaves are ovate or ovate-lanceolate, entire, up to £ meter 
long, broad or rather narrow, petioled or sessile (Fig. 424). They are 
glandular-hairy. The veins form loops near the margins. 


The general structure of the leaf is learned from cross-sections (Fig. 
425); the details of chief value in diagnosis from surface preparations 
of the epidermis (Figs. 426 and 427). 

Epidermis. The cells are large, and on the lower surface have dis- 

Fig. 425. Tobacco. Cross section through midrib, epo upper epidermis; p palisadt 
cells; m spongy perenchyma; c collenchyma; epi lower epidermis; g fibro-vascular 
bundle; K crystal sand; h jointed hair; dk glandular hairs. X 100. (Moellf.r.) '■.-- 



tinctly wavy walls. Stomata are about three times as numerous on the 
under surface as on the upper. The clammy hairs are all multicellular, 

Fig. 426. Tobacco. Upper epidermis. X160. (Moellek).* 

Fig. 427. Tobacco. Lower Epidermis. X160. (Moeixer.) 

with thin walls and a broad base, but are of four forms: (1) jointed 
with pointed or blunt apex; (2) like the first, but branching. (3) glandu- 


lar with multicellular head and jointed stem; (4) like the last, but with 
short unicellular stem. The first three forms reach an extraordinary 
length, and are usually evident to the naked eye. The cuticle is striated 
and often granular on the surface. 

Mesophyl. The chlorophyl parenchyma is brown. Numerous cells 
filled with crystal sand are present. 


The characteristic elements are the epidermis with the four forms 
of multicellular hairs, also the mesocarp cells with crystal sand. The 
epidermal cells with hairs are readily found in surface preparations of 
fragments from cigars, smoking and chewing tobacco, also in powder 
mounts of snuff. The latter, being made from the coarser part of the 
leaf, contains a preponderance of vascular elements. Before searching 
for adulterants the material should be boiled with dilute alkali, filtered 
and washed. 

Hauenschild states that leaves of the following are used in tobacco: 
Cherry, artichoke, linden, acacia, walnut, sunflower, arnica, watercress, 
hemp, rose, oak, dock, betony, chestnut, melilot, and especially beet, 
cabbage, chicory, and potato. In the manufacture of plug tobacco 
the following materials are employed: Common salt, sirup, sugar, 
licorice, rum, sal-ammoniac, prunes, tamarinds, vanilla, essential oils, 
benzoic acid, carob beans, saltpetre, potash, cloves, anise, violet root, 
gum, dextrine, etc. Various materials, in powder form, may be used as 

In Germany the revenue law allows the addition to tobacco of a cer- 
tain percentage of cherry and rose leaves (see pp. 468-471). English laws 
prohibit the use of the following: Sugar, sirup, molasses, honey, malt 
sprouts, roasted seeds, . chicory, lime, sand, umber, ocher or other earths, 
seaweed, roots, moss, and all leaves and herbs. 

Some of the leaves used as adulterants are described elsewhere in 
this work; others must be learned by experience. Usually all that is 
necessary is to prove that the leaf is not tobacco. 



See General Bibliography, pp. 671-674: Moeller (30, 31, 32); Molisch (33); 
Planchon et Collin (34); Vogl (44); Krasser(48). 

Koning: Der Tabak. Leipzig, 1900. 
Kissling: Der Tabak. Berlin, 1893. 



Under the head of spices and condiments are here grouped all products 
used merely for flavoring. They include certain fruits (pepper, cayenne, 
allspice, anise, vanilla, etc.), seeds (nutmeg, mustard, etc.), roots (gin- 
ger, horseradish, etc.), barks (cassia, cinnamon, and clove bark), flower 
buds (cloves, capers, cassia buds), leaves and herbs (sage, savory, bay 
leaf, etc.). 

Mustard seeds are described for convenience with other cruciferous 
seeds in the section on oil seeds. 

Turmeric, a root allied to ginger, and saffron, the stigmas of Crocus 
sativus, although chiefly valuable as dyes, are also classed as spices. 

The valuable constituents of most spices are essential oils, although 
the pungent principles of mustard and horseradish are sulphur com- 
pounds, and the capsicin of cayenne pepper and paprika, as well as 
the vanillin of the vanilla bean, are crystalline solids. The tissues and 
other elements, although useless for seasoning, are of chief service 
in diagnosis. 

The Impurities of spices introduced through accident or through 
faulty methods of collecting, curing, cleaning, and handling, include 
dirt, small stones, woody matter, extraneous parts of the plant, weed 
seeds, and insect contamination. 

Mineral Matter. Dirt in the form of dust is deposited during the 
growing or ripening periods on fruits, barks and leaves, but not, of course, 
on seeds protected by the pericarp. It is washed off to some extent by 
rains, but, on the other hand, rains often spatter mud on low-growing 
plants, thus seriously injuring the quality of the product. It is well 
known in the trade that, for this reason alone, cayenne pepper, sage, 
and other spices, differ greatly from year to year in cleanness. 

Certain commercial varieties of black pepper, such as Acheen, 

1 The descriptions of barks (excepting cassia), rhizomes, leaves, and flowers are by 
Prof. J. Moeixer. 



Lampong, Tellicherry, etc., are sun-dried on the ground, and as a con- 
sequence are contaminated with lumps of dirt, stones, sticks, etc., while 
Singapore pepper, being a fire-dried product, is much cleaner. 

Ginger and other roots are freed from adhering soil by washing, but 
the undecorticated sorts, such as African and Calcutta, are seldom abso- 
lutely clean when placed on the market. 

Scraped cassia and Ceylon cinnamon are usually quite clean, while 
unscraped cassia, and particularly cassia chips, are often more or less 
contaminated with adhering dirt. Low grade or broken China cassia 
is particularly dirty. 

Limed nutmegs and " bleached " ginger are coated with a thin layer 
of calcium carbonate which is said to prevent the ravages of insects, and 
is not, therefore, regarded as an adulteration. 

Penang white pepper is invariably coated with a brown-gray layer 
consisting largely of calcium carbonate. 

Extraneous Matter from the plant itself, such as stems in cayenne 
pepper, cloves, allspice, umbelliferous fruits, and various leaves, also 
shells in nutmegs and pepper, should be present only in very small quanti- 
ties in properly cleaned spices. The fact that the impurity is produced 
by the same plant as yields the spice is no valid excuse for not removing 
such an impurity or for its willful addition. Clove stems, for example, 
are as much an adulterant in ground cloves, as would be sawdust made 
from the clove tree. 

Weed Seeds are accidental impurities of mustard and umbelliferous 
seeds, from, which they can be largely removed by sifting. Most of the 
other common spices, are not subject to this kind of contamination. 

Insects, although avoiding certain spices rich in essential oil, cause 
great havoc in certain others. The drug-store beetle is almost sure to 
make its appearance in whole unlimed ginger, if stored for a long time, 
burrowing through the roots and transforming nearly the whole product 
into an unappetizing powder. Cayenne pepper and paprika, both whole 
and ground, are attacked by a small moth which spins a dense web through 
the material. Nutmegs used for grinding are often light-weight kernels 
from which the starchy matter has been almost entirely eaten out by insects, 
leaving only the brown resinous veins. Mites and other insects infesting 
cereal products, also occur in mustard flour mixed with wheat flour, corn 
meal, and other cereal adulterants. 

Adulterants. Probably no class of food products has been so grossly 
adulterated as ground spices. The incentive is unusually great owing 


to their high cost and their strong odor, which conceals a considerable 
admixture of worthless material. 

A list of the adulterants includes a great variety of cheap materials 
in powder form, and also certain dyes and pigments, added to conceal the 

Inorganic Materials. These are partly diluents, such as calcium 
sulphate, calcium carbonate, brick-dust, coal-ashes, sand and clay, and 
partly pigments, such as Venetian red and chrome yellow. Because of 
their greater weight they are used less often than vegetable materials. 
Calcium sulphate (piaster of Paris or gypsum) is occasionally added to 
mustard flour and ground ginger, but not to the dark-colored spices. 
Brick-dust has been found in cayenne pepper, coal-ashes in white pepper, 
and sand in various spices. Venetian red (iron oxide) is used in imitating 
the color of cloves, allspice, cinnamon, and nutmeg, while chrome yellow 
formerly was used in mustard. 

Organic Material. Among the numerous diluents of vegetable origin 
are flour, bran and chaff of the cereals ; hulls, bran, and other products of 
buckwheat; screenings; peas, beans, and other legumes; linseed meal, 
cottonseed meal, ground cocoanut cake, and other oil cakes; cocoanut 
shells (raw and charred), almond shells, and other nut shells ; olive stones ; 
sawdust, red sandalwood, and other woody materials; clove stems, 
mustard hulls, pepper shells, exhausted spices, and other waste products 
from spices. Other adulterants are : cayenne pepper, added to adulterated 
black pepper to reinforce its pungency; turmeric and other dyes used to 
color mustard; red coal-tar dyes added to cayenne pepper; and finally 
Bombay mace, a worthless substitute for true mace. This list is far from 
complete, but includes the materials most commonly employed. 

The analyst will be greatly aided in his search by a knowledge of the 
available materials and commercial practices in his own country. For 
example, ground hazelnut shells is a distinctively European adulterant, 
while ground cocoanut shells is distinctively American; also rape, sun- 
flower, and several other oil cakes are used in Europe, while only linseed 
and cottonseed cakes are commonly available in America. 

Hints on the detection of foreign materials are given in the final section 
under each spice. 

Identification of Ground Spices in spice mixtures or other food products 
is sometimes desirable, and for this purpose the key on p. 498 may be 
found useful. 


Methods of Examination. 

Preliminary Examination. The odor and especially the taste of the 

different spices is, as a rule, so characteristic, that complete substitution 
of other products would be recognized even by a layman. But adulterations 
with inert substances are not so readily detected by either the sense of 
smell or of taste, although one with experience will often find cause for 

The color is a valuable guide, as it is no easy matter to color fraudulent 
mixtures so as to exactly imitate the genuine. For example, colored 
mustard flour is almost always much yellower than the uncolored, and. 
colored cayenne pepper is of a somewhat different shade from the genuine. 
Texture and "grain" are also altered by the addition of foreign sub- 

After removing the finer material by sifting, or separating into strata 
by jarring on a sheet of paper, suspicious fragments may often be picked 
out under a lens. These are first examined as to their color, texture, 
hardness and similar physical characters and then crushed or macerated 
for microscopic examination. 

Chemical Analysis. The following determinations, applicable to most 
of the spices, are of value in diagnosis: total ash, ash soluble in water, 
sand (ash insoluble in hydrochloric acid), fixed oil (non-volatile ether 
extract), essential oil (volatile ether extract), alcohol extract, crude fiber, 
crude starch (copper- reducing matters by direct inversion), pure starch 
(by the diastase method), and total nitrogen. 

If the quantity of ash is excessive, it should be examined for sand, 
calcium sulphate, iron oxide, and similar impurities. 

Determination of essential oil is especially valuable in the examination 
of cloves, as this spice normally contains as high as 20 per cent of this 
constituent, but in the examination of other spices is of lesser importance, 
the percentage being usually small and exceedingly variable. 

Although possessing no pungent qualities, certain fixed oils are char- 
acteristic constituents of mustard, mace, cayenne, and other spic es. 

Determination of crude fiber aids greatly in detecting nut shells, saw- 
dust and similar woody adulterants, while determination of starch serves 
both to detect starchy adulterants in non-starchy spices, and non-starchy 
adulterants in starchy spices. 

Among the processes applicable only to certain spices are the determina- 
tion of crude piperine (nitrogen in the non-volatile ether extract) in black 


and white pepper; of cold-water extract in ginger (to detect exhausted 
ginger); of tannin in cloves and allspice; also the qualitative tests for 
Bombay mace, turmeric, coal-tar colors, etc. 

Microscopical Examination is by far the most valuable, and in many 
cases the only, means of detecting vegetable adulterants in spices. Even 
in cases where chemical analysis furnishes evidences of foreign admixtures, 
microscopic examination is usually essential to determine the nature and 
origin of that admixture. As a rule this examination coupled with a 
determination of ash is all that is needed in pronouncing on a suspected 

The microscopist who undertakes this work should have at his command 
for comparison authenticated samples of whole and ground spices as well 
as of spice adulterants. 

Direct Examination in water of the finely ground material and of sus- 
pected fragments picked out under the lens, also a second examination, 
after the addition of iodine, serves for the identification of the starch 
grains and some of the tissues. The same portion should afterward be 
treated with a small drop of alkali, thus rendering the tissues more dis- 
tinct. Another valuable clearing agent is chloral hydrate solution, in 
a few drops of which a small portion of the material is allowed to soak 
for some hours. 

Of the characteristic reactions for the detection of particular spices 
only two need here be mentioned, namely, the change from yellow to 
brown-red of fragments of turmeric on treatment with ammonia, potash 
or soda, and the red color imparted to hulls of charlock on heating with 

In the simple manner described most of the adulterants can be de- 
tected by one familiar with the elements of the spices themselves and 
of the adulterants. Treatment with other reagents is sometimes useful 
but seldom essential. 

The Special Methods of preparing the material for microscopic 
examination described under flour (p. 52), and cereal feeds (p. 58) 
ere applicable for starchy spices, or spices containing an admixture of 
starchy matter, while those described under oil seeds products (p. 171) 
are applicable for spices free from starch. The crude fiber process is 
one of the most useful of these methods. It is, however, seldom necessary 
to resort to preliminary treatment, as direct examination in water or some 
other medium, and treatment with reagents on the slide, are usually 
quite as satisfactory. 


Analytical Key to the Common Spices used in Powder Form. 

A. Starch present; epidermal tissues with stomata absent. 

(a) Starch grains minute (2-10 /i), polygonal, forming compact masses. 

* Stone cells present, those of the hypodermal layer small, thick -walled. 

1. Endocarp of small stone cells (less than 50 fi) with broad cavity. . .Pepper. 

2. Endocarp of large stone cells (over 50 /1) with narrow cavity Cubebs. 

3. Endocarp of very large, porous, elongated cells Long Pepper. 

** Stone cells absent. 

4. Mosaic of brown, thick -walled palisade cells Cardamom. 

(b) Starch grains medium size (up to 20 n), rounded, often in small aggregates; 

hilum distinct. 

5. Stone cells and bast fibers present Cinnamon ' and Cassia. 

6. Stone-cells present; bast fibers absent; tissues of spermoderm port-wine 

color Allspice. 

7. Neither stone cells nor bast fibers present; tissues of perisperm brown. 


(c) Starch grains large (mostly over 20 /1), pear-shaped; hilum excentric; reticulated 

vessels present. 

8. Starch grains perfect; bast fibers present; tissues nearly colorless. -Ginger. 

9. Starch grains mostly in formless masses; bast fibers absent; tissues bright 

vellow, becoming brown-red with alkali Turmeric. 

B. Starch absent; epidermal tissues with stomata absent except on calyx of 12 and 13. 

10. Palisade cells of spermoderm form a brown mosaic with darker reticulations. 

Brown Mustard. 

11. Palisade cells of spermoderm form a yellow mosaic without reticulations. 

White Mustard. 

12. Epidermal cells of pericarp polygonal, with yellow walls; ground tissue 

contains yellow or red oil drops Paprika. 

13. Same as last, but epidermal cells quadrilateral, in rows. . . Cayenne Pepper. 

14. Epidermis of large elongated cells; ground tissue contains amylodextrine- 

starch grains (red with iodine) Mace. 

15. Yellow color soluble in water; pollen grains often present ; Saffron. 

C. Starch grains absent (except in chlorophyl grains); epidermal tissues with stomata 


(a) Chlorophyl absent. 

16. Numerous oil cells; crystal cells in rows beside spiral vessels Cloves. 

17. Brown jointed oil ducts present Umbelliferous Fniits (p. 551). 

(b) Chlorophyl present. 
* Hairs absent. 

18. Epidermal cells with thick, wavy walls Bay Leaf. 

** Epidermis with simple, jointed and disk-shaped (glandular) hairs. 

t Hairs smooth. 

1 Cassia buds have small starch grains, epidermal hairs, and numerous bundles. 


19. Jointed hairs very numerous, long, narrow, pointed Sage- 

tt Hairs warty or smooth. 

20. Jointed hairs numerous, long, broad, straight, thin-walled Marjoram. 

21. Hairs very numerous, mostly short, conical Thyme. 

22. Hairs few, those with joints bent near the end, thin-walled Savory. 

Condimental Cattle and Poultry Foods. 

Numerous proprietary mixtures of cereal or oil-seed products, with 
aromatic substances, simple drugs and other materials, are extensively 
advertised as food auxiliaries, appetizers and tonics for bovine cattle, 
horses, swine and poultry. They occupy a place between ordinary 
cattle foods on one hand and condition powders on the other, and are 
sold at prices out of proportion to the value of their constituents, with 
extravagant claims as to their nutritive and curative properties. As 
foods they are of no greater value than the common feeds of which they 
are largely composed, while as tonics they are counterparts of numerous 
patent medicines for human use. 

As various aromatic substances are characteristic ingredients, they 
are properly considered with the spices. 

The Constituents may be classed under three heads : (1) food materials, 
(2) spices, including fenugreek, and (3) drugs. 

The food materials include a number of common feeds of greater or 
lesser value, such as bran and other by-products of wheat, maize meal, 
gluten meal, linseed meal, bean meal, carob-bean meal, malt -sprouts, 
cocoa shells, etc. With these should be classed salt, ground bone, ground 
meat, crushed sea shells and ground quartz (the last four being con- 
stituents of poultry foods), all of which are useful in the animal economy. 
Of the spices, fenugreek is probably the most extensively employed, 
the characteristic odor of many preparations being due to this constituent. 
Ginger, cayenne pepper and mustard hulls are also common ingredients, 
while anise and fennel are stated to be present in some mixtures. 

The drugs are partly vegetable and partly mineral. 

The bitter taste of most of the mixtures is due to ground gentian root, 
the cheapest of the bitter drugs, although wormwood is sometimes em- 
ployed. Charcoal serves not only as a- remedy, but also to give the mix- 
ture a gray color, thus concealing other constituents. Licorice, lobelia, 
bloodroot, elecampane, and other drugs are less often used. 

Among the mineral drugs reported by analysts are sulphur, Epsom 
salts (magnesium sulphate), Glauber's salts (sodium sulphate), potassium 
chlorate, and Venetian red (iron oxide). 


Methods of Examination. 

Preliminary Examination. The hints given under cereal cattle foods 
(p. 58), oil-seed products (p. 170), and spices (p. 496) apply also to con- 
dimental foods. 

Fenugreek, ginger, cayenne pepper, and umbelliferous seeds are 
characterized by their odor and taste; gentian, common salt, and other 
salts by their taste; charcoal and Venetian red by their color; ground 
quartz by its gritty nature. 

Vegetable constituents can often be picked out for microscopic exami- 
nation, and small crystals of Epsom and Glauber's salts, lumps of sulphur, 
fragments of sea shells and other mineral constituents, for chemical 

Chemical Examination. Qualitative Tests are made for chlorine 
(common salt), sulphuric acid (Epsom and Glauber's salt:), magnesia 
(Epsom salts), carbonic acid (calcium carbonate), lime (calcium carbon- 
ate and phosphate), phosphoric acid (calcium phosphate), iron (Venetian 
red), sulphur, etc. 

These tests can all be made on quite small particles picked out from 
the material. Those soluble in water are conveniently dissolved in a 
minute drop of water and a drop of the reagent added from a stirring 
rod. In this way we can detect in fragments weighing less than a milli- 
gram, chlorine by silver nitrate, sulphuric acid by barium chloride, mag- 
nesia by sodium phosphate. Carbonic acid of calcium carbonate is 
recognized by the effervescence with dilute hydrochloric acid, while 
lime is detected in the same portion, after making alkaline with ammonia, 
on addition of ammonium oxalate. The phosphoric acid of bone in a 
nitric acid solution gives, on heating with ammonium molybdate solu- 
tion a bright-yellow precipitate. Sulphur burns with a blue flame 
giving off sulphurous vapors. Iron is best detected in the ash by its 
red-brown color and the red-brown precipitate of ferric hydrate ob- 
tained after dissolving in hydrochloric acid and addition of ammonia. 
Powdered charcoal is recognized by the fact that it is not bleached 
by boiling with aqua regia or a mixture of potassium chlorate and nitric 
acid, also by the gray color of the crude fiber obtained by the usual 

Quantitative Analyses. The usual proximate constituents (water, 
ash, protein, crude fiber, nitrogen-free extract, and fat, or rather ether 
extract) are determined, and if mineral drugs are present their constitu- 


ents are also quantitatively determined. Carbonic acid is determined 
in the original material: Chlorine in the water solution; sulphuric acid, 
and magnesia, either in the water solution of the original material or the 
acid solution of the ash; phosphoric acid, calcium oxide and iron oxide 
in the acid solution of the ash, and sulphur in the ether extract after 
oxidation to sulphate. 

Microscopic Examination. The special methods described on pp. 497 
may be used in preparing the material for examination, although as a 
rule the finely ground material and fragments picked out under a lens 
may be suitably examined in water, and again after treatment with iodine, 
alkali, or other reagents. 

Cereal products are recognized by the characteristic starch grains 
and the tissues of the bran and chaff; starchy leguminous seeds by 
the ellipsoidal starch grains with elongated hilum, also by the tissues of 
the spermoderm; linseed meal by the rectangular pigment cells with 
deep brown contents, and yeUow-brown fragments consisting of the 
superimposed fibers and subepidermal cells; cottonseed meal by the 
yellow cell-contents of the embryo, the brown resin particles becoming 
red with sulphuric acid, and the remarkable- elements of the black 

Fenugreek is usually present in relatively small amount, and it is 
often a tedious search to find fragments showing the characteristic pointed 
palisade cells and the broad column cells with ribs. This is especially 
true if linseed meal is present, as the spermoderm of this seed is also of 
a brown color. Of some aid in the search is the bright-yellow color 
imparted to the spermoderm by alkali. 

The most characteristic elements of umbelliferous seeds are the oil 

Cayenne is identified by the characteristic rectangular cells of the 
epicarp, with thick yellow walls, the intestine cells of the spermoderm, and 
the yellow or red oil drops. 

The chief elements of ginger are the large pear-shaped starch grains 
with excentric hilum, although the reticulated vessels and long bast fibers 
occur in small amount. 

Gentian, unfortunately, has no characteristic tissues, but in the absence 
of ginger the reticulated vessels, coupled with the bitter taste, furnish 
an indication of its presence. 

Charcoal in powder form appears under the microscope as black 
opaque particles, which are not affected by any of the ordinary reagents. 


These particles may be found unchanged in the crude fiber obtained 
by the ordinary acid and alkaline treatment, also in the residue after 
bleaching, as already described. 


Black pepper, long pepper, and cubebs are single-seeded berries with 
the reserve material largely in the bulky perisperm. 

Hypodermal stone cells of the usual type are found in the pericarp 
of all three berries, while the endocarp of each is characteristic of the 
species, consisting in cubebs of several layers of large stone cells, in black 
pepper, of a single layer of small cells thickened in the inner part (beaker 
cells), and in long pepper of large elongated cells with moderately thick 
walls. In all three species very small, polygonal starch grains fill the 
cells of the perisperm. The largest grains occur in long peppe r. 


Both the black and the white peppercorns of commerce are berries 
of Piper nigrum L., a climbing perennial indigenous to Malabar and 
Travencore, and cultivated in Sumatra, Siam, Borneo, Java, Ceylon, the 
Philippines, and tropical America. 

The vine reaches a length of 1 5 meters, and attaches itself to trees, 
rocks, or trellises by means of aerial roots thrown out from the joints. 
The inflorescence is in spikes up to 10 cm. 'long, either terminal, or oppo- 
site leaves, bearing 20-50 flowers, each nearly hidden from view by two 
bracts. The flowers appear in May or June, and the fruit, a one-seeded 
berry, ripens six months later, changing during ripening from green to 
red and finally to yellow. 

Black peppercorns are the green berries dried without shelling, either 
in the sun or over fires. Owing to the shrinking of the meat during 
drying, the black or green shell, consisting of pericarp and spermoderm, 
is strongly wrinkled. 

White peppercorns are the berries, picked usually when fully ripe, 
which have been freed from the outer shell. The process commonly 
employed consists in soaking the berries in salt water or lime water, 
rubbing off the shell either with the fingers or by machinery, and drying; 

— FS 


but in some regions the shell is removed dry. The corns are of a light 
gray color, and while not so pungent as black pepper, have a finer flavor. 

Pepper is a notable example of a seed with reserve material almost 
entirely in the perisperm (Fig. 428). This perisperm forms the body 
of the seed, and has a cavity in the center one mm. 
or more in diameter and a smaller cavity in the 
apex containing traces of embryo and endosperm. 
The outer portion of the perisperm is horny, the 
inner portion floury. 

The grades of pepper on the market are desig- Tl °p^ e S rnig f^ LcSJ! 
nated according to their places of growth, or oftener tudinal section of fruit. 
.,. _. f t- 4. c- c- ^ n- E endosperm; N pen- 

their ports of shipment, as Singapore, biam, 1 elli- sperm; FS pericarp and 

cherry, Trang, Lampong, Acheen, Penang, etc. $£££j erm - X3 " 
Singapore black pepper, one of the best grades, is 

fire-dried, and consequently has a smoky odor and taste. Most of the 
other peppers, being sun-dried on the ground, do not have this quality, but 
are more or less contaminated with stems, earth, small stones, and in 
the case of Acheen, the poorest sort, with empty and light-weight kernels. 
Acheen pepper is sifted free of coarse shells before shipment and sepa- 
rated into grades A, B, C, D, according to the specific gravity; but the 
empty or light-weight kernels are more or less broken up during the sea 
voyage and handling, so that the product is invariably contaminated with 
more or less shells. Penang white pepper is coated with a gray substance 
consisting chiefly of carbonate of lime. 

The characteristic constituents of pepper are: (1) Piperine, an inert, 
non- volatile, crystalline substance, (5-8 per cent) ; (2) piperidine, a vola- 
tile alkaloid; (3) clavacin, a pungent resin; and (4) an aromatic vola- 
tile oil. Starch varies up to 40 per cent in black pepper and up to 60 per 
cent in white pepper. 


Black peppercorns, sectioned either dry or after soaking in water, 
serve for the study of all the elements of the fruit; white peppercorns 
for all the elements but the outer pericarp. Clearing of the tissues may 
be effected either by heating with dilute alkali, or better by soaking in 
Javelle water. 

Pericarp (Figs. 429 and 430). To the naked eye the pericarp in black 
pepper is black or gray-black throughout, but in white pepper all that 
remains of the pericarp, namely the inner layer, is light gray. 


i. The Epicarp (ep) consists of polygonal cells (15-30 (i) and occasional 
stomata, covered by a cuticle 5 fi thick. In the dried berries the contents 
are dark brown or black. 

2. Hypoderm (ast). Small thin-walled cells, intermingled with strongly 
thickened, often radially elongated, porous, yellow stone cells, form the 
hypodermal layer. Both forms of cells often contain a dark-brown 
material, which takes on a reddish color with alkali. The stone cells 
vary greatly in size and are among the most conspicuous elements of the 
fruit, but are of course absent in white pepper, while pepper shells, removed 
in the preparation of white pepper, contain them in extraordinarily large 

3. Outer Mesocarp. The mesocarp is differentiated into four more or 
less distinct layers. In the outer layers most of the cells are of moderate 
size, and contain minute starch grains or chlorophyl; but here and there 
larger cells with suberized walls contain oil or resin. This is the innermost 
of the layers removed in preparing white pepper. 

4. Bundle Layer (fv). In the next layer, consisting of smaller, more 
or less compressed cells, ramify the nbro-vascular bundles. 

5. Oil Cells (p). An interrupted layer of large cells with suberized 
walls and oily contents is evident in cross-section. 

6. An Inner Mesocarp of thin-walled but porous cells completes the 
pulpy part of the pericarp. 

7. Endocarp (ist). Beaker Cells, so called because of their thickened, 
sclerenchymatized inner and radial walls, form the inner stone cell layer 
or endocarp. As seen in cross-section, they are horseshoe-shaped with 
distinct pores. Surface preparations are also characteristic, the double 
porous walls being thinner than in the stone cells of the outer layers. 

Spermoderm (Figs. 429 and 430). This forms a thin layer of little 
diagnostic importance. 

1. Outer Epidermis (is). Vogl and some other authorities cons'der 
the elongated cells of this layer as belonging to the spermoderm; Tschirch 
and Oesterle, however, who have studied its development, believe that 
it is a portion of the pericarp. Its connection with the spermoderm is 
best seen in the vicinity of the micropyle, where the cells are largest and 
thickest-walled. Over the body of the seed they are much compressed and 
are scarcely evident except after heating with alkali, or bleaching with 
Javelle water, washing in dilute acetic acid and staining. This latter 
treatment not only causes the compressed cells to assume their original 
shape, but also greatly swells the walls. 



2. Middle Coat. This consists of one or two layers of elongated cells 
similar to those of the epidermis. 

Fig. 429. Black Pepper. Cross section of outer layers of fruit. Pericarp consists of ep 
epicarp, ast hypodermal stone cells, oil outer mesocarp with oil cells, jv bundle zone, 
* oil cells, and ist endocarp ; spermoderm consists of is outer epidermis, and inner layers 
(not- shown) ; perisperm consists of al aleurone cells, am starch masses, res resin cells, 
and pip piperin crystals. (Moellee.) 

3. Pigment Layer. Owing to the dark-brown tannin substance, the 
elongated cells of this layer are conspicuous both in cross section and 



surface view, although their cell-structure is not clearly seen except after 
treatment with alkali or some other reagent. Under favorable conditions 
the walls appear distinctly beaded. Iron salts impart a blue color to the 

Perisperm (Figs. 429 and 430). 1. Hyaline Layer. This is evident 
in cross section as a hyaline band inclosing not only the inner layers of 




** ^ > 9 » 

3 <*& 

Fig. 430. Black Pepper. Elements of powder, ep epicarp; ast hypodermal stone cells; 
bf bast fibers; bp bast sclerenchyma ; sp vessels; p oil cells; ist endocarp; ij,ojlayers 
of spermoderm; am starch masses. X160. A starch grains, X600. (Moeller.) 

the perisperm, but also the embryo and endosperm at the end of the seed. 
As it does not show evidences of being pierced by the micropyle, it is 
here classed with the perisperm. Evidences of the cellular structure 
appear on treatment of cross sections with alkali. In surface view the 
cells are elongated polygonal with thin walls. 

2. Aleurone Cells (al). Macroscopic examinations of a kernel cut in 
half show that the outer portion is horny, while the inner portion, sur- 
rounding the central cavity, is mealy. If cross sections are treated with 
iodine solution and examined under the microscope, it is evident that the 
cells of the two or more outer layers are small and contain aleurone 
grains, but no starch. 

PEPPER. 5°7 

3. Starch Cells {am). The inner portion of the perisperm consists 
of large, radially elongated cells, up to 150 pt long, filled with masses 
of minute starch grains embedded in proteid matter. The starchy con- 
tents of the inner cells separate as compact masses conforming to the 
shape of the cells, in which are evident not only the individual grains, but 
sometimes also oval aggregates of grains such as occur in rice and oats. 
Pepper starch grains are among the smallest in the vegetable kingdom, 
being usually 2-4 ft in diameter and never exceeding 6 p.. They are 
polygonal or rounded and have an evident hilum. Strikingly different from 
the polygonal cells containing aleurone grains and starch are the rounded 
resin cells (res) distributed here and there among these. In these are con- 
tained yellow globules of oil, also lumps of resinous matter, and often 
needle-shaped crystals of piperin (^>). These latter are seen in greater 
numbers after mounting in alcohol, allowing the alcohol to evaporate 
slowly, and remounting in water. The piperin is soluble in alcohol and 
ether, but insoluble in water. If sections are placed in a drop of 
concentrated sulphuric acid a deep-red solution is obtained. 

Endosperm and Embryo are minute and are of no diagnostic importance. 


Black Pepper, although prepared from the green berry, contains all 
the microscopic elements of the fruit in practically full development. Of 
greatest importance in identification are the outer stone cells (Fig. 430, 
ast), the beaker cells (ist), and the masses (am) consisting.of minute starch 
grains (^4). Sulphuric acid dissolves the piperin to a deep-red solution, 
but other members of the genus give the same reaction, and its value is 
further impaired by the fact that similar red solutions are obtained with 
cottonseed and other products. 

Ground Black Pepper, since it contains both the dark tissues of the 
pericarp and spermoderm and the light -colored starchy perisperm, is of a 
dark-gray or brown-gray color. It is more pungent than white pepper, 
although the natural flavor is often mingled with an earthy or, in the case 
of fire-dried varieties, with a smoky flavor. 

The adulterants of pepper are probably more numerous and varied 
than those of any other food product, not excepting coffee. They include 
linseed meal, buckwheat hulls, nutshells (cocoanut, walnut, almond, 
hazelnut, etc.), mustard hulls, screenings, charcoal, cereal - products, 
peas and other leguminous seeds, poppy seeds, olive stones, sawdust, 
cocoa shells, pepper hulls, mineral diluents and colors, exhausted pepper, 



Fig. 431 

Hairs from 

Black Pepper. 

exhausted spices, — in fact any waste material with a not too pro- 
nounced flavor that can be easily reduced to a powder. It is a common 
practice to mix light- and dark-colored adulterants in order to better 
imitate the color of the genuine product, and also to 
add a little cayenne pepper to give pungency to 
fraudulent mixtures which otherwise would be 
nearly tasteless. Nutshells, sawdust, buckwheat 
hulls, cocoa shells, pepper shells, and other fibrous 
or woody materials have much higher amounts of 
crude fiber but less starch than genuine pepper, 
while the reverse is true of most starchy adulterants. 
The ether extract of pepper consists largely of pip- 
erin, a nitrogenous substance, whereas the extract 
of some of the adulterants contains no appreciable 
amounts of nitrogen. As Acheen pepper contains 
a considerable amount of loose shells and conse- 
quently a high percentage of ash and fiber, it is 
frequently not possible either by microscopic exami- 
spindie. nation or chemical analysis to distinguish this 
grade in powder form from a better grade adul- 
terated with pepper shells. Legal standards of composition are designed 
to exclude pepper unfit for consumption, whether ground from a very 
low grade of berry or willfully mixed with shells. 

White Pepper is usually prepared from the ripe berry, the globular 
corns, although deprived of the outer layers of the pericarp, being usually 
somewhat larger than black peppercorns and free from wrinkles. They 
are light gray, lusterless, and delicately veined with the pericarp bundles. 
Penang white pepper is coated with a gray substance consisting largely 
of carbonate of lime. The portion of the pericarp removed consists of 
the epicarp, the hypodermal stone cells, and the outer mesocarp up to 
the bundles. Except for these layers, the microscopic elements are the 
same as in black pepper, any difference due to degree of ripeness being 
too slight for detection. As the powder is of a light -gray color, the adul- 
terants used are light-colored materials, such as wheat flour, maize meal, 
ground rice, buckwheat flour, and various other cereal products, ground 
peas and other legumes, white poppy seeds, ground olive stones, cayenne 
pepper, also gypsum and other white mineral substances. Cereal adul- 
terants do not greatly alter the percentage of starch, but are readily de- 
tected by the characters of the starch granules and the tissues. Olive 

PEPPER. 5°9 

stones increase the crude fiber and diminish the starch. White and 
black pepper are both characterized by the nitrogen of the ether extract, 
due to piperin. 

Decorticated White Pepper, consisting of peppercorns deprived of all 
the coats of the pericarp and spermoderm, is made from black pepper in 
machines of special construction. The powder is light yellow, of a deli- 
cate fragrance, and contains, in appreciable amount, only the elements 
of the perisperm. Because of the lack of other elements, adulteration 
is the more readily detected. 

Pepper Shells, obtained in the manufacture of white pepper, being 
cheap, pungent, and difficult of detection, are frequently mixed with 
ground black spepper. They show a preponderance of stone cells under 
the microscope, and contain a high percentage of fiber and ash, the latter 
being due largely to adhering dirt. 


See General Bibliography, pp. 671-674: Berg (3); Blyth (5); Fluckiger (11); 
Greenish (14); Hanausek, T. F. (io, 16); Hassall (19); Leach (25); Mace (26); 
Moeller (29, 30, 31, 32); Planchon et Collin (34); Schimper (37) ; Tschirch u. Oesterle 
(40); Villiers et Collin (42); VogI (43, 45)- 

Andouard: Falsification du poivreparle Galanga. Jour, pharm. chim. 1890, 21, 585. 
Eeythien: Ueber Gewiirze. Ztschr. Unters. Nahr.-Genussm. 1903, 6, 957. 
Bertarelli: Verfiilschung von weissen Pfefferkornern. Atti della Societa Piemontese 

d'Igiene. 1900-01, 7. 
Bertschinger: Kunstliche Pfefferkomer. Schw. Woch. Chem. Pharm. 1901, 39, 215, 
Eonnet: Du poivre et de ses falsifications. These E. de Ph. de Paris. 1886, 19. 
Erown: On Another New Pepper Adulterant. Analyst. 1887, 12, 89. 
Brunotti: Des fruits utiles des Piperitees. These d'agregation. Concours, 1889, 31. 
Chevreau: Recherche de la falsification du poivre par le grignon d'olives au moyen 

des sels d'aniline. Rep. de Pharm. 1889, 17, 203. 
Daels: Falsification du poivre blanc en poudre. Journ. Pharm. d' An vers. 1904, 60, 1. 
Giixet: Method nouvelle pour reconnaitre la falsification des poivres par addition de 

grignons d'olives. Bull. soc. chim. 1888, 50, 173. 
Gladhill: Commercial Pepper. Amer. Jour. Pharm. 1904, 76, 71. 
Grimaldi: Sopra una falsificazione del pepe in grani. Staz. sperim. agrar. Ital. 1901, 

34, 705. 
Hanausek, E.: Schwarzer Tellicherrypfeffer. Ztschr. Nahr.-Unters. Hyg. 1888, 2, 5. 
Hanausek, T. F. : Ueber die Harz- und Oelraume in der Pfefferfrucht. Sep.-Abdr. 

aus Programm der k. k. Staatsrealschule am Schottenfelde, Wien, 1886. 
Hanausek, T. F. : Ueber die Matta. Ztschr. Nahr.-Unters, Hyg. 1887, 1, 24. 
Hanausek, T. F. : Kunstlicher Pfeffer. Ztschr. allg. osterr. Apoth.-Ver. 1887, 12, 180. 
Hanausek, T. F.: Im Budapester Handel beobachtete Pfefferfalschungen. Ztschr. 
" Nahr.-Unters. Hyg. 1889, 3, 33 , 58. ' 


Hanausek, T. F.: Kiinstliche Pfefferkorner. Ztschr. Nahr.-Unters. Hyg. 1889,3,31. 
Hanausek, T. F.: Die Pfefferfruchtspindeln. Ztschr. Nahr.-Unters. Hyg. 1889, 3, 59. 
Hanausek, T. F.: Ueber einige, gegenwartig im Wiener Handel Vorkommende 

Gewurzfalschungen. Ztschr. Nahr.-Unters. Hyg. 1894, 8, 95. 
Hanausek, T. F. : Ueber den schwarzen Pfeffer von Mangalore. Ztschr. Unters. Nahr.- 

Genussm. 1898, 1, 153. 
Hanausek, T. F.: Ueber eine neue Pfefferfalschung. Ztschr. Unters. Nahr.-Genussm. 

1898, 1, 490. 
Hanausek, T. F. : Olivenkerne und ihre Erkennung im Pfefferpulver. Pharm. Cen- 

tralh. 1885, 25, 261. 
Hebert: Moyen facile et rapide de reconnaitre la falsification du poivre. Joum. 

pharm. chim. 1891, 23, 283. 
Jumeau: Note sur les falsification du poivre en poudre. Journ. pharm. chim. 1889, 

20, 442. 

Kundrat: Das neueste Verfalschungsmittel fiir Pfeffer. Ztschr. Nahr.-Unters. Hyg. 
1895, 9, 104. 

Landrin: Falsification du poivre a l'aide des grignons d'olive. Jour. Pharm. 10, 194. 

Mainsbrecq: Falsification du poivre. Bull. Assoc. Beige Chim. 1901, 15, 335. 

Martelli: Nachweis der Yerfaschungen des gemahlenen Pfeffers. Ztschr. Nahr.- 
Unters. Hyg. 1895, 9, 205. 

Mennechet: Sur une falsification du poivre par les fruits du Myrsine Ajricana L. et 
Embelia ribes Burm. Jour, pharm. chim. 1901, 14, 557. 

Meyer, Arthur: Die mikroskopische Untersuchung von Pflanzenpulver, speziell tiber 
den Nachweis von Buchweizenmehl in Pfefferpulver und iiber die Unterscheidung 
des Maismehls von dem Buchweizenmehl. Arch. Pharm. 1883, 21, 911. 

Moeller: Ein neues Verfalschungsmittel fiir Pfeffer. Rep. anal. Chem. 1886, 409. 

Moeixer: Matta. Pharm. Post, 1886, 365. 

Molinari: Nachweis von Olivenkernen im Pfeffer. Rev. chim. anal. appl. 1898, 6, 6. 

Morpurgo: Delle Spezie. Trieste, 1904. 

Nestler: Ueber Verfalschungen von Macis, Pfeffer und Safran. Ztschr. Unters. 
Nahr. Genussm. 1903, G, 1033. 

Neuss: Zur Pfefferuntersuchung. Pharm. Ztg. 1885, 30, 26. 

Pabst: Nachweis einer Pfefferfalschung durch Olivenkerne mittels Anilinsalzen. Rev. 
internat. falsificat. 1889, 3, 8. 

Pabst: Recherches des grignons d'olives dans le poivre. Journ. pharm. chim. 1890, 

21, 645. 

Paolini: Sopra una nuova falsificazione del pepe comune. Staz. sperim. agrar. Ital. 

1901, 34, 966. 
Petnemann: Beitriige zur pharmakognostischen und chemischen Kenntniss derCubeben 

und der als Verfalschung derselben beobachteten Piperaceenfruchte. Arch. 

Pharm. 1896, 234, 204. 
Planchon: Note sur le poivre et les grignons d'olive. Jour, pharm. chim. 1885, 11, 641. 
Rau: Ueber neuere Verfalschungen des gemahlenen Pfeffers. Ztschr. offentl. Chem. 

1900, 6, 243. 
Raumer und Spaeth: Falschungen von Gewiirzen und anderen Nahrungsmitteln. 

Ztschr. Unters. Nahr.-Genussm. 1902, 5, 409. 


Rimmington: Pepper Adulteration and Pepper Analysis. Analyst. 1888, 13, 81. 
Spaeth: Ueber ein neues Verfalschungsmittel des gemahlenen Pfeffers. Forschber. 

Lebensm. Hyg. 1893, 1, 37. 
Teyxeira e Ferruccio: Pepe naturale ed artificiale. Boll. Chim. Farm. 1900, 

39, 534- 
Uhl: Zur Untersuchung des Pfeffers. Forschungsb. Lebensm. Hyg. 1886, 127. 
Wender: Kunstpfeffer. Ztschr. allg. osterr. Apoth.-Ver. 1887, 25, 145. 


Two species yield the long pepper of commerce, Piper officinarum 
DC, grown in Java, the Philippines, India, and other parts of the East 
and P. longum L., sparingly cultivated in India, the former species being 
by far the most important. 

The inflorescence is in a dense spike which ripens into a dark-gray 
or black compound elongated catkin-like fruit consisting of numerous 
consolidated berries. The surface bears spiral rows of small protuber- 
ances, which are the exposed outer ends of the individual berries. Each 
compound fruit is 2-6 cm. long and 4-7 mm. broad in the case of P. offici- 
narum, somewhat shorter and thicker in the case of P. longum. 


After soaking over night in water, the compound fruit is in excellent 
condition for cutting longitudinal and transverse sections, corresponding 
respectively to transverse and longitudinal sections of the individual 
berries. These sections should be soaked in Javelle water to swell out 
the layers of the spermoderm and stained. 

Pericarp. Owing to the consolidation of the lower portions of adjoin- 
ing pericarps, the epicarp and hypoderm are developed only on the outer 
end of each individual. 

1. The Epicarp is of polygonal cells with no distinctive characters. 

2. Hypodermal Stone Cells do not form a continuous layer, but are 
scattered here and there through the outer cell layers. A few of these 
stone cells also occur in the middle layers of the consolidated pericarp 

3. The Outer Mesocarp, composed of parenchyma cells (no oil cells), 
contains numerous small starch grains and traces of chlorophyl. 

4. Inner Mesocarp. The mesocarp cells show little differentiation up 
to the inner two or three layers, where they grade into the sclerenchy- 
matized, thickened, porous cells of the endocarp. This transition is 


brought out by safranin after bleaching with Javelle water. The inner 
layers contain no starch and are none of them typical oil cells. 

5. Endocarp. Most characteristic of all the tissues are the large, 
longitudinally elongated, porous, sclerenchyma cells of this layer, which 
are radically different from the small beaker cells of pepper or the 
strongly thickened stone cells of cubebs. They form striking objects 
in tangential or surface sections, especially after staining, and in trans- 
verse or longitudinal section are conspicuous because of the thickened 
inner walls and the decrease in thickness of the radial walls from within 

6. An Inner Layer of beaded cells with slightly undulating walls may 
be found by examining the inner surface or the fragments obtained by 
scraping. These cells or their inner portions also occur on the spermo- 
derm. It is probable that this layer belongs to the pericarp and corre- 
sponds to the cells Tschirch and Oesterle find in unripe black pepper. 
Those cells of ripe black pepper which they regard as these pericarp 
cells in a later stage of development appear to belong to the spermo- 

Spermoderm. Cross-sections show little detail until treated with 
Javelle water, after which the structure is clearly analogous to that of 
black pepper and cubebs. 

1. The Outer Epidermis, as may be seen after treating either cross- 
sections or surface preparations as described, has swollen outer and 
radial walls even more striking than those of black pepper and cubebs. 
Surface preparations show that the cells are longitudinally elongated, 
12-20 fi broad. 

2. The Middle Coal, consisting mostly of one or two layers, but at the 
base of a number of layers, has cells with swollen walls much like those 
of the outer epidermis. 

3. The Pigment Cells are readily found in transverse or surface sec- 
tions, and after removal of the pigment by Javelle water, are seen to be 
distinctly reticulated, the radial walls appearing beaded in surface view. 

Perisperm. 1. Hyaline Layer. The swollen, structureless outer 
membrane, the so-called " hyaline layer " regarded by many authors 
as the inner spermoderm, is the same as is found in pepper and other 
members of the genus. 

2. The Aleurone Cells are small and contain little or no starch. 

3. Starch Parenchyma, with no evidence of oil cells, form the inner 
perisperm. The polygonal or rounded starch grains vary from 2-10 fi, 


being usually about 4 //, or a little larger than those of black pepper. 
Concentrated sulphuric acid produces a deep carmine color due to piperin. 


Long pepper has been repeatedly detected by English analysts as an 
adulterant or substitute for black pepper. It is distinguished by the 
somewhat larger starch grains, and especially by the large, elongated, 
moderately sclerenchymatized cells of the endocarp, and the absence 
of beaker cells and oil cells. The powder also has a distinctive odor. 


Cubebs, the fruit of a vine (Piper Cubeba L.), although properly classed 
with the drugs, are of interest to the food microscopist because they are 
analogous in structure to the fruits of black and long pepper. At the 
present time cubebs are seldom used as spices, but the exhausted berries 
are sometimes mixed with black pepper as an adulterant. 

The plant grows in Sumatra, Java, and other islands of the East Indies. 

The dark-brown, wrinkled berry is about the same size as a black 
peppercorn, which it further resembles in morphological structure. Unlike 
black pepper, the berry is borne on a stem 6-8 mm. long, and the seed, 
often only partially developed, is not united with the sides of the peri- 
carp. Among the constituents are volatile aromatic principles, and cube- 
bin, a non-volatile crystalline substance related to piperin. 


Although cubeb and pepper berries are analogous in microscopic 
structure, certain of the elements are strikingly different. 

Pericarp. 1. The Epicarp of small polygonal cells is hardly dis- 
tinguishable from the corresponding coat of pepper, although the cell- 
contents are usually of a lighter color. 

2.' The Hypodermal Stone Cells, 24-40 ji in diameter, are not usually 
radially elongated and are for the most part in a single layer. 

3. The Outer Mesocarp is composed of parenchyma cells contain- 
ing small starch granules (2-6 ft) and oil cells containing crystals of 
cubebin in addition to fatty matter. 

4. Compressed Cells form that portion of the mesocarp through which 
ramify the bundles. 


5. The Inner Mesocarp of several layers of parenchyma cells inter- 
spersed with oil cells contains no starch grains. 

6. The Endocarp, or inner stone-cell layer, is much more strongly 
developed than the corresponding beaker cells of pepper. It consists 
of one or more layers of large isodiametric or radially elongated stone 
cells (often 80 ft) with walls thickened on all sides. 

7. An Inner Layer of irregular cells lies between the endocarp and 
spermoderm. In cross-section this layer is scarcely distinguishable, but 
on examining the inner surface of the pericarp or the outer surface of 
the spermoderm, the thin beaded side walls are clearly evident. 

Spermoderm. Cross-sections show the same number of layers as is 
found in black pepper. 

1. Outer Epidermis. The longitudinally elongated cells, often 150- 
200 fi long and 25-50 /x wide, are much larger than any of the elements 
of the spermoderm of pepper. In surface view they are recognized, after 
heating with alkali or after bleaching with Javelle water and staining 
with safranin, by their size, more or less rectangular form, and swollen 
brown walls (double walls 10-15 //). 

2. A Middle Coat of one or two cell layers is present in most parts 
of the seed. The narrow cells are elongated and the walls are swollen 
after treatment with the reagents named. 

3. Inner Epidermis. Irregular cells, often longitudinally elongated, 
with walls of even thickness or faintly beaded, form a dark-brown pig- 
ment layer not unlike the corresponding cells of both black and long 
pepper. Like these latter, as may be seen in longitudinal section, they 
are tabular except near the micropyle, where they are radially elongated. 

Perisperm. 1. A Hyaline Layer forms a thickened, apparently struc- 
tureless membrane enclosing the perisperm, the embryo, and endosperm; 
the two latter being situated in a small hollow at the apex. 

2. Aleurone Cells constitute several outer layers. 

3. Starch Parenchyma intermingled with yellow-green oil cells make 
up the heart of the perisperm. The starch grains are rounded or polyg- 
onal, 3-12 jj. in diameter, and are closely packed in the cells. Sections 
mounted in concentrated sulphuric acid take on a deep carmine color. 


The powder is distinguished from ground pepper by the larger starch 
grains, the presence of large stone cells in place of beaker cells, and the 
large cells of the middle spermoderm. The elements of the stem are 


also present, the large sclerenchymatized bast parenchyma being espe- 
cially noteworthy. 


See General Bibliography, pp. 671-674: Berg (3); Meyer, A. (27); Moeller (31, 32); 
Planchon et Collin (34); Tschirch u. Oesterle (40). 
Dewere: Recherches sur le cubebe, etc. Ann. Soc. roy. sci. m£d. nat. de Bruxelles, 

1894, 3. 
Hastwich: Weitere Beitrage zur Kenntniss der Cubeben. Arch. Pharm. 1898, 236, 

Hartwich: Cubeba Real-Enzykl. d. ges. Pharm. 2 Aufl. IV, 1905. 
Peinemann: Beitrage zur pharmakognostischen und chemischen Kenntniss der Cubeben 

und der als Verfalschung derselben beobachteten Piperaceenfriichte. Arch 

Pharm. 1896, 234, 204. 
Vogl: Falsche Cubeben. Pharm. Centralh. 1895, 36, 11. 
Wevre: Ueber Cubeben und ihre Verfalschungen. Apoth.-Ztg. 1895, 10, 345. 


Cayenne pepper and paprika, the two species of capsicum used as 
spices, are characterized by the sclerenchyma cells of the epicarp and 
endocarp, the yellow or red oil drops of the mesocarp, and the curious 
intestine cells of the spermoderm. Starch in appreciable amount is 


Various species of the genus Capsicum yield pungent fruits widely 
different in form, size, and color, which serve both for seasoning food and 
in medicine. Throughout the Continent, the large fruit of C. annuum L. 
is much used as a spice and is coming into use in the United States. 
The Hungarian product, which is most highly esteemed, is known as 
paprika, the Spanish as pimiento. The latter serves to color catsup and sau- 
sage. As it is practically without pungency it hardly deserves to be classed 
as a spice. Pungent varieties are also grown in Mexico and South 

The conspicuous red or yellow shining fruit of paprika is inflated) 
5-10 cm. long, and from half to three-fourths as broad. The pericarp, 
even before drying, is but a few millimeters thick, the bulk of the fruit 
consisting of the fruit cavity divided at the base into two or three com- 
partments. Numerous flattened seeds (3-5 mm.), shaped much like the 
human ear, are borne in the lower part of the fruit on the central placenta, 
and in the upper part on the partitions which here only extend part way to 



the center. The embryo, with a long radicle and still longer, narrow 
cotyledons, is coiled within the endosperm in such a way that the radicle 
points toward the elongated (2 mm.) hilum. The hollow stem, 3-4 mm. 
in diameter, and the small, green, pentagonal or hexagonal calyx aie at- 
tached to the dried fruit as found on the market. 


Any of the large garden peppers or the dried whole paprika fruit 
may be employed for studying the histology. 

The Fruit Stem (Fig. 432) has an epidermis and outer cortical layer, 
like the corresponding layers of the calyx in structure. Wood elements 

Fig. 432 Paprika (Capsicum an- Fig. 433. Paprika. Surface view of calvx show- 
nuum) Elements of stem, b ing outer epidermis with st stoma, and > spongy 

bast fiber; bp bast parenchyma; parenchyma. X160. (Moeller.) 

/ wood fibers; hp wood paren- 
chyma; spitted vessels. X160. 

form a continuous hollow cylinder surrounded by a narrow, interrupted 
bast ring. The elements of the wood, consisting of pitted and reticulated 
vessels, libriform fibers, and wood parenchyma, are strongly thickened, 
while the bast contains a characteristic element in the form of broad (up 
to 50 ji), flexible fibers with wide cavities. 



Calyx. Sections of the dry material swell considerably in water, dis- 
playing an uncommonly large-celled tissue. 

1. The Outer Epidermis (Fig. 433), as seen in surface view, consists 
of large, flat, moderately thick- walled, sharply-polygonal cells, with a few 

2. Mesophyl (Fig. 434). Adjoining the outer epidermis is a single 
layer of cells in close contact with each other, and a similar layer adjoins 
the inner epidermis, but in the middle layers the cells are larger and thinner- 

Fig. 434. Paprika. I cross section of calyx showing t hairs of inner (upper) epidermis 
and gjb fibro-vascular bundle. II inner (upper) epidermis of calyx, in surface view. 
(Tschirch and Oesterle.) 

walled, forming a spongy parenchyma. Through the inner layers run 
the fibro-vascular bundles. Chlorophyl is present in the hypodermal 
layers, but not in the spongy parenchyma. 

3. The Inner Epidermis (Fig. 434) has moderately large cells with wavy 
walls but no stomata. Characteristic are the peculiar glandular hairs. 
These are short, two or more celled, with single or compound end cells 
containing red-brown resinous bodies. Noteworthy is the fact that they 
are not, like, most hairs, simply epidermal cells prolonged beyond the 
surface, but they spring from the middle of much broader cells after the 
manner of root-hairs. 

Pericarp, Outer Wall. In cutting sections, the material should be 



held between pieces of pith or embedded in paraffine and care taken to 
avoid tearing away the inner layers. 

i. Epicarp (Fig. 435, epi; Fig. 436). This layer, in cross-section, 
has a cuticularized and thickened outer wall 15-20 ft thick. In surface 
view the cells are polygonal, moderately thin-walled (double walls 3-8 fi) 

Fig. 435. Paprika. Pericarp in cross section, epi epicarp; mes mesocarp with oil glo- 
bules, and jv fibro-vascular bundle; g giant cells; end endocarp. (Moeller.) 

beaded, 45-95 fi in diameter. They are not, as in Cayenne pepper, 
rectangular and arranged in rows. 

2. Hypoderm. Several layers of collenchyma further distinguish 
paprika from Cayenne pepper. As was first shown by Molisch, the walls 
of these layers, as well as of the epicarp, are suberized, and become yellow 
with alkali. Contained in both the hypoderm and mesocarp in the fresh 
condition are oil drops and red chromoplastids which give the fruit its 



characteristic color. Viewed in water, the oil drops from the dried fruit 
are of a bright orange or red color due to the solution of the coloring 

Fig. 436. Paprika. Epicarp in surface view, showing narrow grooves. (Moeller.) 

matter of the chromoplastids, and are of great aid in diagnosis. Concen- 
trated sulphuric acid imparts an indigo-blue color to the globules, a reaction 
due to the action of the acid on the coloring matter. Exceedingly minute 

Fig. 437. Paprika. 'Elements of pericarp in surface view, ep epicarp; coll collenchyma; 
en endocarp with si sclerenchyma cells. X160. (Moeller.) 

starch grains are occasionally found in some of the cells, particularly if 
the fruit is not fully ripe. 



3. Mesocarp (Fig. 435, mes). The cells in the middle portion of the 
pericarp are thin-walled and not characteristic except for their contents. 
Through these cells run the bundles. 

4. Giant Cells (Fig. 435, g). Adjoining the endocarp is a layer of, 
cells of enormous size, often 1-2 mm., separated from each other by smaller 
cells. They are best seen in carefully prepared transverse sections. 

These cells are evident to the naked eye 
on the inner surface of the pericarp as 
longitudinally elongated blisters (Fig. 


5. Endocarp (Figs. 435 and 437)- 
The most characteristic layer of the 
pericarp is the endocarp, made up over 
the giant cells of groups of scleren- 
chyma elements and in other parts of 
thin-walled cells, both kinds of cells be- 
ing more or less elongated and quadri- 
lateral with wavy outline. Penetrating 
the radial walls of the sclerenchyma 
cells are distinct pores which broaden 
at the middle lamella. 

Pericarp, Partition Walls. Cross- 
sections of the partition walls show that the mesocarp consists of thin- 
walled elements of no especial interest, while the endocarp cells are more 
or less thickened. As was discovered by Arthur Meyer, the cuticle here 
and there separates from the cells, forming blister-like cavities in which 
are tabular or prismatic crystals of capsaicin, the pungent principle of 
the fruit. If alkali is run under the cover-glass, the crystals at first dis- 
appear, but others of octahedral form, the alkali compound, take their 
place. If these blisters are opened and the minutest portion of the con- 
tents transferred to the tongue by means of a needle, an intense 
burning sensation is experienced. In the fully ripe fruit this pungent 
principle is distributed throughout the pericarp and also the seeds. 

The Spermoderm (Figs. 439 and 440) has an outer and inner epidermis, 
and between them a parenchymatous layer several cells thick, all of which 
are evident in sections cut from the dry seed. 

1. The Outer Epidermis (ep) of highly characteristic elements, has 
been carefully studied by Arthur Meyer, T. F. Hanausek, and others. 
Seen in cross-section, the outer wall is a cellulose band of even thick- 

Fig. 438. Paprika . Endocarp and giant 
cells in surface view. (Moeller.) 


5 2 i 

ness (12-50 fi), covered without by a thin cuticle and within by an equally 
thin sclerenchymatiaed lining, while the radial and inner walls are enor- 
mously but irregularly thickened and sclerenchymatized. From the inner 
wall wart-like protuberances extend into the cell cavity. The radial 
walls diminish in thickness from within outward, resembling buttresses. 
Where they meet the outer wall, they are pierced by pores which, in 
cross-section, appear as slits between finger-like divisions. At the edges 
of the seed, where the cells often have a radial diameter upwards of 
200 ft, these pores occur in the greatest 
numbers. In surface view the appear- 
ance differs according to the depth of the 
focus. On the inner wall we see warts, 
pores, and wrinkles ; on the outer, an even 
structure bounded by the curiously sinuous 
and porous radial walls. The appear- 

Fio. 439. Paprika. Outer portion of seed in cross Fig. 440. Paprika. Spermoderm 

section. Spermoderm consists of ep epidermis, p in surface view. ep epider- 

parenchyma, and inner layers of compressed paren- mis; p parenchyma. X160. 

chyma; £ endosperm. X160. (Moeixer.) (Moeller.) 

ance of the latter is best described by the term "intestine cells," first 
applied to this layer by Moeller. * 

2. Middle Layers (p). Thin- walled cells, in the dry seed more or 
less compressed, form several indistinct layers. 

3. An Inner Epidermis, also of thin-walled elements, in cross-section, 
is clearly seen to be in close contact with the endosperm. 

The Endosperm (Fig. 439, E) consists of moderately thick-walled 
cells containing aleurone grains and fat as reserve material. A crystal- 
loid is present in each of the aleurone grains. 

Embryo. Of little interest to us are the delicate tissues of the em- 
bryo. The cell-contents are the same as in the endosperm, except that 
the aleurone grains are somewhat smaller. 



The powder is either red, yellow, or brown, according to the variety 
or the method of preparation, and the oil drops, seen under the micro- 
scope, are of the same color as the fruit. Treatment with concentrated 
sulphuric acid imparts a blue color to the oil drops. 

The endocarp (Fig. 437) of elongated, sinuous cells, some scleren- 
chymatized (st), others thin-walled (en), and the curious intestine cells 
(Fig. 440, ep) of the outer epidermis of the spermoderm, are the tissue ele- 
ments most easily found and identified. Starch is seldom present in 
noticeable amount, and never in the form of large grains. Tissues of 
the stem and calyx should not be overlooked. The epicarp cells (Fig. 436) 
are polygonal, have moderately thick, beaded walls, and are easily dis- 
tinguished from the quadrilateral cells in rows of the corresponding layer 
of Cayenne pepper. 

The adulterants of paprika are various products of cereals and oil 
seeds, nutshells, sawdust (particularly of red sandalwood (Fig. 28) and 
other red or brown woods), turmeric, brick-dust, etc. If the material 
is not of a suitable color it is often dyed with coal-tar colors, or mixed 
with a pigment. Addition of oil darkens the color. 

The color of red sandalwood is extracted by treatment with alkali; 
the coal-tar dyes commonly employed are readily transferred to a bit 
of woollen cloth, previously heated with very dilute soda, by boiling with 
1 per cent solution of potassium bisulphate — a method first devised by 
Arata for testing wines. 


See General Bibliography, pp. 671-674: Berg (3); Greenish (14); Hanausek, T. 
F. (10, 16, 17, 48); Harz (18); Hassall (19); Leach (25); Mace" (26); Meyer, A. (27, 28); 
Moeller (29, 30, 31, 32); Planchon et Collin (34); Schirnpcr (37); Tschirch u. Oesterle 
(40); Villiers et Collin (42); Vogl (43, 45). 
Hartwich: Ueber die Epidermis der Samenschale von Capsicum. Pharm Post. 1894 

27, 609, 633. 
Hartwich: Ueber die Samenschale der Solanaceen. Vjschr. d. naturf. Ges. in Zurich. 

1896, 41, Jubelband II, 366. 
Hanausek, T. F.: Ueber die Samenhautepidermis der Capsicum-Arten. Ber. d. 

deutsch. botan. Ges. 1888, 6, 329. 
Lohde: Ueber die Entwicklungsgesch. und den Bau einiger Samenschalcn. Dissertation, 

Leipzig, 1874, 26. 
Meyer, Arthur: Der Sitz der scharfschmeckenden Substanz im spanischen Pfeffet. 

Pharm. Ztg. 1889, 34, 130. 


5 2 3 

Miklown: Adulteration of Spanish Pepper. Weekly Drug News. 1886, 215. 
Molisch: Collenchymatische Korke. Ber. d. deutsch. botan. Ges. 1889, 7, 364. 
Morptjrgo: Delle Spezie. Trieste, 1904. 
Vedrodi : Untersuchung des Paprikapfeffers. Ztschr. Nahr.-Unters. Hyg. 1893, 7. 


This spice, also known as red pepper and chillies, is much more pun- 
gent than paprika and is preferred to the latter in England and the 
United States. It is obtained from Capsicum fastigiatum Bl. (C. mini- 
num Roxb.), C. frutescens L. and other small-fruited species grown in 
various parts of Africa, the East Indies, and tropical America. 

Zanzibar Cayenne pepper, one of the best grades, consists of small 
pods 0.5 to 2 cm. long, of a dull-red color, together with slender, more 
or less detached stems. The seeds are but 3-4 mm. in diameter. 

Bombay peppers, known also as capsicums, are an inferior grade 
of Cayenne pepper, said to come from the vicinity of the river Niger in 
Africa, not as the name would indicate, from India. The dull yellow 

Fig. 441. Cayenne Pepper {Capsicum frutescens). Epicarp in surface view. x~x, x'-x' 
rows of cells; h thickened horizontal walls; v abnormally thickened cell. (T. F. 

or brown fruits are larger than Zanzibar peppers (2-3 cm. long and nearly 
1 cm. broad), but do not differ from them in structure. 

Japan Cayenne peppers are about the same size as the Zanzibar 
product, but are brighter in color and more glossy, although not so pun- 
gent. Their anatomical structure would indicate that they* are fruits 
of a different species. 

5 2 4 



While the structure is analogous to that of paprika, certain elements 
are strikingly different, thus enabling the microscopist to distinguish 
sharply between the two species. 

The Pericarp of the dry fruit is hardly thicker than a sheet of writing- 

i. Epicarp (Figs. 441 and 442). In surface view this coat is radically 
different from that of paprika. The cells are usually quadrilateral, more 
or less wavy in outline, and what is most noticeable, are arranged in dis- 
tinct longitudinal rows. They are smaller than those of paprika, being 
but 20-55 P- m diameter, and have indistinctly beaded walls, which (double) 
are 3-5 fi thick. 

2. Hypoderm. Cross-sections show that a hypodermal collenchyma 
of suberised cells is entirely absent, the character of the tissues chang- 

FlG. 442. Cayenne Pepper {Capsicum jastigiatitm). Epicarp in surface view. Xn° 


ing abruptly from the thick, sclerenchymatous epidermis to the thin- 
walled tissues of the mesocarp. This distinction, however marked in 
cross-section, is not of service in the examination of the powder. 

3. The Mesocarp, and 4. The Giant Cells are quite like the corre- 
sponding layers of paprika. 

5. The Endocarp Cells of the two species are also very similar, but 
are somewhat smaller in Cayenne pepper. 


Spermoderm. i. The Epidermal Cells are of the same general form 
as those of paprika, but the inner sclerenchymatized lamella of the 
outer wall is more strongly developed than the middle lamella, whereas in 
paprika the middle lamella alone is conspicuous. In surface view the 
cells are somewhat smaller than the epidermal cells of paprika. 

2. The Middle Layer, and 3. The Inner Epidermis are not character- 

The Endosperm and Embryo agree in structure with the correspond- 
ing parts of paprika. 


In cross-sections the lack of sclerenchymatized collenchyma in the 
hypoderm, the thinner mesocarp, and the broader inner lamella of the 
outer wall of the spermoderm serve to distinguish this fruit from paprika. 
These distinctions are of no service in the examination of the powder, 
but the highly characteristic epicarp cells (Figs. 441 and 442) suffice for 
positive identification. 

Characteristic elements common to both fruits are the oil drops of 
a red or orange color, the, thick- and thin-walled cells of the endocarp 
(Fig. 437, st, en), and the outer epidermal cells (Fig. 440, ep) of the sper- 
moderm (intestine cells). ^ 

The adulterants of both powders are the same and are enumerated 
under paprika. 


See General Bibliography, pp. 671-674: Greenish (14); Hanausek, T. F. (10, 16 
17, 48); Hassal (19); Moeller (29, 30, 31, 32); Planchon et Collin (34); Vogl (43, 45)! 

See also Bibliography of Paprika p. 522 
Hanausek, T. F.: Zur Charakteristik des Cayennepfeffers. Ztschr. Nahr.-Unters Hyg. 

1893, 297- 
Istvanffi: Zur Charakteristik des Cayennepfeffers. Bot. Centralbl. 1893, 3, 468. 
Wallis: The Structure of Capsicum minimum. Pharm. Jour. 1901, 13, 552. 
Waixis: The Structure of Japanese Chillies. Pharm. Jour. 1902, 69, 3. 
Wallis: Capsici Fructus. Pharm. Jour. 1897, 59, 467. 



Allspice is the only fruit of this family of importance as a spice. Cloves, 
the leaf bud of a myrtaceous plant, is described on p. 397. 


Although most of the plants producing spices are natives of the East, 
the tree yielding allspice, pimenta, or Jamaica pepper, {Pimenta offi- 
cinalis Lindl.), is an American species, growing wild in the West Indies, 
South America and Mexico, and extensively cultivated in Jamaica. Its 
fine form, abundant, shining evergreen foliage, and delightful fragrance 
combine to make it an attractive object in tropical gardens. 

Tobasco or Mexican allspice, is a large-berried variety of P. officinalis, 

regarded by some as a separate species. Crown allspice (Poivre de The- 

bet), the fruit of Pimenta acris Sw., with berries 8-10 mm. long, is also 

gathered in tropical America. Both of these have practically the same 

• structure as common allspice. 

The fruit at full maturity is a two-celled, less often one- or three-celled, 
dark purple berry 5-8 mm. in diameter, crowned with a four-toothed 
calyx; each cell contains a plano-convex, chocolate-colored seed. The 
spice of commerce consists of the berries picked when fully formed, but 
still green, and dried in the sun. The berries are dark brown with a 
rough surface and have a flavor supposed to resemble a mixture of cloves 
with other spices, hence the English name allspice. 

The seeds consist of a brown spermoderm and a snail-like, spirally- 
coiled embryo with a long thick radicle and minute cotyledons. They 
contain from 3-6 per cent of a volatile oil, and are therefore but about 
one-quarter as strong as cloves, the product of a tree of the same family. 


After soaking in water, whole berries and seeds removed from the 
berries, separate sections are prepared of the pericarp and spermoderm. 

Pericarp (Figs. 443-445). The outer wall of the pericarp, which 
differs somewhat in structure from the partitions between the cells, is 
first examined. 

1. Epicarp Cells (Fig. 444, ep) of notably small size, containing a 
dark-brown material, and here and there well developed stomata, form 


5 2 7 

the outer layers of the pericarp. Hairs up to 200 ft long, characterized 
by their thick walls, and in their outer portions by their exceedingly 
narrow lumens, are scattered over the surface, particularly in the neigh- 
borhood of the calyx teeth. 

2. The Outer Mesocarp with Oil Cavities, forming about one-quarter 
of the thickness of the pericarp, should first be studied in cross-section. 
The ground tissue consists of small thin-walled cells somewhat larger 

Fig. 443. Allspice (Pimenla officinalis). Outer wall of pericarp in cross section, oil 
oil cells; st stone cells of mesocarp. (Moeller.) 

than those in the epicarp, those about the oil cavities forming one or 
more concentric layers. The oil cavities (Fig. 443, oil) are rounded sacs, 
up to 200 /i in diameter, similar to those occurring in cloves. Over 
these the epicarp and mesocarp are somewhat distended, forming the 
wart-like irregularities seen on the surface of the fruit. 



3. The Inner Mesocarp with numerous Stone-Cells (Fig. 443, st) makes 
up the major part of the pericarp. The cells of the ground tissue increase 
in size from without inward, and are either empty or contain formless 

brown masses or else crystal clusters of cal- 
cium oxalate. The stone cells are irregular 
in shape and have colorless walls more or 
less strongly thickened, in which branching 
pores and concentric markings are conspicu- 
ous. They are distributed through the par- 
enchymatous ground tissue, being especially 
numerous in the inner layers, where they 
form a nearly continuous coat one or more 
cells thick. 

4. Compressed Cells in several layers line 
the cavity of the berry. In surface view 
these cells, particularly those in the inner 
layer, are polygonal in form. 
We find in the parchment -like partition walls epidermal layers of 
polygonal cells, a more or less obliterated ground tissue containing crys- 
tal clusters, and distributed through the ground tissue numerous fibro- 
vascular bundles and occasional stone cells (Fig. 445). 

Spermoderm (Fig. 446). Cross-sections show that this layer is thin 
on the edges of the seed, but on the broad sides forms thick cushions. 

Fig. 444. Allspice. Surface view 
of ep epicarp and st oil cells. 
X160. (MOELLER.) 

Fig. 445. Allspice. Elements of partition wall in surface view. X 160. (Moellee.) 

. i. The Outer Epidermis (ep) is of narrow elongated cells. 
2. The Middle Layers (p) are characterized by the pigment cells of 
irregular form with contents of a clear port-wine color, which are readily 



found in the powdered spice. It is these cells that form the greater part 
of the thickened portion on the sides of the seed. Fibro-vascular bundles 
of the raphe and its branches ramify in the inner layers. 

3. An Inner Epidermis of elongated cells is seen in surface view. 

Vogl notes that the spermoderm is divided into an outer coat including 
the pigment cells and bundles, and an inner coat of but a few cell layers. 
As the inner coat is not evident in all seeds or in all parts of the same 

Fig. 446. Allspice. Spermoderm in surface view, ep epidermis; p brown parenchyma 

(port wine cells). (Moeller.) 

seed, it is possible that it does not belong to the spermoderm, but is a 
remnant of the endosperm or perisperm. 

Embryo (Fig. 447). On soaking seeds for a day or two in if per cent 
caustic-soda solution, the spermoderm may be removed from the em- 
bryo. Under a lens the latter is seen to consist of a long radicle coiled 
in a snail-like spiral of two turns, diminishing in size from the thick lower 
end near the hilum of the seed to the upper end bearing the minute coty- 
ledons. Cross-sections of the seed pass through the radicle in two or 
more places and may also pass through the cotyledons. By far the 
larger part of the seed is radicle. 

1. The Epidermal Cells contain coloring matter but no starch. 


2. Oil Cavities in a ground tissue of parenchyma, similar to those 
of the pericarp, form a ring about the radicle. 

3. Starch Cells make up the great mass of tissues. The rounded" 

starch grains (up to 12 pi) have a distinct hilum and are often united 

into twins or triplets. They resemble closely the starch of nutmeg and 



The chief elements of allspice powder are rounded starch grains 
(Fig. 447), occurring singly, in pairs, or triplets, each with a distinct 
hilum; pigment cells (Fig. 446, p) of the spermoderm with port-wine- 
colored contents (blue or green with ferric chloride) ; white stone cells of 
the mesocarp; oil cavities of both the mesocarp and embryo; small epicarp 
cells; and hairs with walls strongly thickened toward the apex. 

Ground allspice is adulterated with various cheap materials, some 
of which, such as clove stems, allspice stems, ground cocoanut and other 


Fig. 447. Allspice. Starch parenchyma of cotyledon. (Moeller.) 

nut shells, cocoa shells, dried pears and red sandalwood, are naturally 
of a brownish color, and others, including cereal preparations, legumes 
etc., are colored brown either by roasting or by the addition of iron oxide, 
dyes, etc. 

Cocoanut shells are distinguished by the isodiametric and slender elon- 
gated stone cells with brown walls, occurring either isolated or in dense 
masses; cocoa shells by the epidermis, the numerous small spiral vessels, 
and the sclerenchyma cells of the spermoderm; sandalwood by the char- 
acteristic wood elements, and the red color extracted by alkali. Other 
adulterants, such as cereal products, legumes, oil seeds, are detected by 
the characters noted under the several seeds. 


Allspice stems are present in small amount as an accidental impurity 
in the genuine allspice of commerce; but when the amount is large, will- 
ful adulteration is to be suspected. A much more common adulterant 
of ground allspice is clove stems, which closely resemble the genuine pro- 
duct in composition and appearance. Spaeth, who has studied the com- 
parative anatomy of the stems of the two plants, finds : (i) allspice stems 
have one-celled hairs of various forms, with a globular thickening on 
one side, while clove stems are not hairy; (2) the bast fibers and wood 
elements of allspice stems are less strongly developed and of a lighter 
color than those of clove stems; (3) the stone cells of allspice stems are 
not abundant, and for the most part are small, light-colored, and uni- 
formly thickened, whereas those of clove stems are more numerous, 
mostly yellow in color, and often thickened only on one side; (4) con- 
spicuous epidermal cells occur only in clove stems. 


See General Bibliography, pp. 671-674: Hanausek, T- F. (ro, 16); Hassall (19); 
Leach (25); Mace" (26); Moeller (29, 30, 31, 32); Planchon et Collin (54); Schimper 
(37); Tschirch u. Oesterle (40); Villiers et Collin (42); Vogl (43, 45). 
Hanausek, T. F.: Ueber einige, gegenwartig im Wiener Handel vorkommende 

Gewiirzfalschungen. Ztschr. Nahr.-Unters. Hyg. 1894, 8, 95. 
Morptjrgo: Delle Spezie. Trieste, 1904. 

Nevinny: Die Piment-Matta. Ztschr. Nahr.-Unters. Hyg. 1887, 1, 46. 
Spaeth: Zur mikroskopischen Priifung des Pimentes. Forschber. Lebensm. Hyg. 

1895, 2, 419. 

NUTMEGS AND MACE (Myristicaceai). 

The terms nutmeg and mace in the legal sense include only the pro- 
ducts of Myristica fragrans. The products of M. argentea are inferior 
substitutes, while Bombay mace is a worthless adulterant. 


True nutmeg is the seed freed from the spermoderm, and true mace 
the arillus or seed mantle, of a tree (Myristica jragrans Houtt.) indige- 
nous to the Moluccas and introduced into Java, Borneo, Sumatra, and 
other regions of the East Indies, as well as into Trinidad, Jamaica, St. 
Vincent and other West Indian Islands. To-day, as in colonial times, 
the Banda Islands produce a large part of the world's supply of these 

53 2 


spices, particularly the better grades, the term "Banda" as applied to 
either nutmeg or mace being a mark of superiority. 

In general appearance the tree resembles the orange tree, having 
shining deep-green leaves. It is dioecious, but to facilitate fertilization 
it is a common practice to graft staminate branches on the pistillate trees. 

The nutmeg fruit resembles a peach in shape and size. On ripening 
the fleshy pericarp splits into two halves, disclosing the dark-brown seed 
closely clasped by the deep-red branching arillus (Fig. 448). 

The mace is removed whole, dried in the sun, and sometimes sprinkled 

Fig. 448. Nutmeg (Myri- 
stica jra grans), enclosed 
in mace or arillus and 
shell or spermoderm. 
Natural size. (Moeller.) 

Fig . 449. Nut- 
meg. Seed, 
natural size. 

Fig. 450. Nutmeg. Cross sec- 
tion showing shell (spermo- 
derm), dark veins (peris- 
perm) and starch tissue 
(endosperm). Slightly en- 
larged. (Berg.) 

with salt to insure its keeping. When ready for the market it varies from 
a buff to a brown color according to the variety and the care taken in 
curing. The seed is also dried, after which the loose nutmeg is removed 
from the hard, dark-brown, shining spermoderm. The latter is 1-2 mm. 
in thickness, furrowed on the outer surface with the imprint of the mace, 
and marked with a band-like raphe running from the hilum at the base to 
the chalaza at the apex. The nutmeg (Fig. 449) is oval, of a cinnamon- 
brown color, and bears numerous longitudinal wrinkles on the surface, 
as well as a groove corresponding to the position of the raphe. Cross- 
sections (Fig. 450) show a beautiful marbled appearance caused by the 
dark-brown branches of the perisperm penetrating into the starchy endo- 
sperm. The relatively small embryo is situated at the base. 

It is the common practice to steep nutmegs in lime-water to prevent 
the ravages of insects as well as to improve their appearance. These 



limed nutmegs have a coat of carbonate of lime which may be removed 
in large part by friction. Penang nutmegs are usually shipped without 


Only nutmeg and mace are usually available for study, although the 
entire fruit preserved in alcohol, and the dried seeds, including the hard 
shell or spermoderm surrounded by the mace, are sometimes obtainable 
from spice importers. 

Pericarp, i. The Epicarp consists of small polygonal cells and 
curious multicellular star-shaped and jointed hairs, or their scars. 

2. Hypoderm. Several layers of small stone cells underlie the epicarp. 

3. The Mesocarp consists of rather thick-walled parenchyma, oil 
cells and numerous branching secretion tubes with brown contents. 

4. The Endocarp is of soft tissues. 

Arillus (Mace) (Figs. 451 and 452). The seed-mantle is a formation 
intermediate between a true arillus (aril) and an arillodium (arillode). 
Near the base, where it is cup-shaped, it divides into flattened branching 

Fig. 451. Mace (Myristica fragrans). Cross section of outer layers, ep epidermis; p 
parenchyma with o oil cells. X160. (Moeller.) 

arms which form an irregular network clasping the seed. As found in 
the market, mace is buff or brown, translucent, brittle, and agreeably 
aromatic, owing to the essential oil present in amounts varying from 
6-15 per cent. Because of the large amount of fat (20-25 P er cent), 
sections should be extracted with ether for the microscopic study of the 
other elements. 

1. Epidermis (ep). The cells are longitudinally extended, some- 
times reaching a length of nearly 1 mm., and vary from 20-40 [i in width. 



At the ends they are either sharply pointed or truncated. From cross- 
sections it appears that the cuticularized outer walls are greatly thickened 
(6-8 pi), and that the other walls are moderately thick and swell con- 
siderably in water. Chlorzinc iodine stains the walls blue, the cuticle 
yellow. These cells are almost always wider than thick, thus differing 


Fig. 452. Mace. Surface view of ep outer epidermis and p parenchyma. X160. 


from the corresponding cells of Bombay mace, which in cross-section 
are radially elongated. 

2. A Hypoderm of collenchyma cells is found in some parts, par- 
ticularly near the base. 

3. Ground Tissue (p) of thin-walled, isodiametric cells 25-50 ft, large 
oil cells up to 80 ft, and nbro-vascular bundles, constitutes the bulk of 
the material. In sections previously extracted with ether, the cells of 
the ground tissue are seen to contain numerous curious, irregular, carbo- 
hydrate bodies with rounded excrescences, ranging in length up to 12 [i, 
which become red or red-brown on addition of iodine. These bodies, 
to which Tschirch has given the name amylodextrin starch, consist of 
a substance intermediate between starch and dextrine, convertible, like 
starch, into a soluble form by malt extract, and into dextrose by heating 
with acid. By the diastase method mace yields 20-30 per cent of so- 
called "starch," or, strictly speaking, amylodextrin starch. The oil 
cells contain a light yellow mixture of essential oil, resin, and fat. Addi- 



tion of alkali does not produce a marked coloration — never a blood-red 
color, as in the case of Bombay mace. 

Spermoderm (Fig. 453). During drying the hard, chocolate-brown 
shell, consisting of the spermoderm with a portion of the outer or primary 
perisperm, separates from the nutmeg. Cross sections may be cut dry 


Fig. 453. Nutmeg. Shell in cross section. 5 spermoderm consists of ep epidermis with 
st starch grains, p parenchyma with g bundle, pal 1 outer palisade layer, and pap inner 
palisade layer with kr crystals; N perisperm with qfs fiber layer. (Hallstrom.) 

and cleared with chloral, potash, or, best of all, Javelle water. Tan- 
gential sections should also be cut of both the outer and inner layers. 

i. Epidermis (ep). Tangential sections show clearly the sharply 
polygonal epidermal cells 20-40 fi in diameter with double walls 3 ft 
thick; also robustly developed stomata. Brownish, amorphous cell- 
contents, and often starch grains are the visible contents. 



2. Parenchyma (p). The cells are thin-walled and contain clear, 
port-wine colored masses readily separating from the cells, also occasional 
crystals of oxalate of lime. Fibro-vascular bundles of the raphe and 
its branches ramify through this layer. 

3. Outer Palisade Layer {pal 2 ). These cells are narrow, thin-walled, 
and about 150/1 high. 

4. Inner Palisade Layer (pal 2 ). By far the larger part of the spermo- 
derm consists of the sclerenchymatized, enormously elongated cells of 
this layer, which vary in height up to 1 mm. and in breadth up to 20 ft. 
The radial walls are remarkably straight, but the narrow lumen is irregu- 
lar in outline, owing to the spiral thickening of the walls. A large crystal 
of calcium oxalate is often present in either end of the cell or in the 
central portion. As seen in cross-section, the cells of both palisade 
layers are wavy in outline, owing to the irregularities of the surface of 
the seed, formed by the pressure of the mace during growth. 

Primary Perisperm (Fig. 453, qfs). 1. Fiber Layer. Tschirch and 
Oesterle have shown that the fibers of this layer are developed from the outer 

layer of the nucellus, and there- 
fore belong with the perisperm. 
_ s Seen in tangential section of 
the inner surface of the shell, 
f they form an interrupted layer 


Fig. 454. Nutmeg. Cross section of kernel. 5 
primary perisperm; F secondary perisperm of 
veins; E endosperm with am starch grains, al 
aleurone grains and / pigment cells. X 160. 

Fig. 455. Nutmeg. Tissues of 
perisperm from surface of kernel 
with brown masses and crystals. 
X160. (Moeller.) 

reminding us in their arrangement of the tube-cells of the cereals. The 
individual fibers are about 15 n broad, but vary greatly in length and 
have irregular outlines. 


2. Inner Layers (Fig. 454, s; Fig. 455). A portion of this tissue clings 
to the inner surface of the shell; the remainder forms the outer coat of 
the nutmeg. In tangential section the cells are rounded, 12-30 [x in 
diameter, with small intercellular spaces. Dark contents, also crystals, 
usually prismatic, less often tabular, which, according to Tschirch and 
Oesterle, have the reactions of bitartrate of potash, are present in the 
cells. The cell- walls are sclerenchymatized. 

The Secondary Perispermm (Fig. 454, F) forms not only the inner 
portion of the enveloping layers of nutmegs, but also the dark fatty folds 
penetrating into the heart of the kernel. The cells are polygonal, for 
the most part smaller than in the primary perisperm, and contain more 
abundant brown contents. The cell-walls are of cellulose. Large 
secretion cells occur in the folds, in some parts in such numbers as to 
form nearly the whole tissue. 

Endosperm (Fig. 454, E). The light-colored portion of the kernel 
constitutes the endosperm, a parenchymatous tissue consisting of starch 
cells and occasional pigment cells. The starch grains range up to 20 li 
in diameter and occur singly, in twins, triplets, and in larger aggre- 
gates. Except for the surfaces of contact, they are rounded. Each 
has a distinct hilum and often radiating clefts. In addition to the starch 
grains, each cell contains an aleurone grain with a large crystalloid. The 
pigment cells contain starch grains embedded in a brown medium. These 
cells are lacking in the central portion of the endosperm (the "conduct- 
ing tissue" of Tschirch and Oesterle) into which the arms of the cotyle- 
dons penetrate during germination. 

The Embryo is located in the basal portion of the seed and has branch- 
ing cotyledons for absorbing the reserve material in the endosperm. 


Whole Nutmegs. By far the larger part of the nutmegs of commerce 
reach the consumer whole, either limed, that is with a loose coat of lime 
adhering, or unlimed, the so-called brown or Penang nutmegs. It is 
customary in the trade to separate each consignment according to size, 
designating the different grades by the number required to weigh a pound. 

It is a well-known tradition that in Colonial times, when spices 
were expensive luxuries, Connecticut Yankees were wont to manufacture 
imitation nutmegs from basswood. Whether or not this story is based 
on facts is uncertain, but a fraud of this kind is no more remarkable than 


molded nutmegs, molded coffee beans, and many other forms of sophis- 
tication practiced at the present time. The name "Nutmeg State," 
at first jokingly applied to the State of Connecticut, is now fixed in the 
language, and will doubtless persist through all time. It is needless to 
say that imitation nutmegs of all kinds, including the molded kernels 
described by Vanderplanken, Ranwez and others, can be quickly identi- 
fied by the appearance and odor on cutting open the kernel. 

Ground Nutmegs appear only in small amount on the market. It 
is no easy task to reduce a sound nutmeg to a powder because of the 
high percentage of oily matter; furthermore, the whole nutmeg keeps 
its flavor better and is readily grated as needed. Immature, worm-eaten 
and other inferior nutmegs are generally used for grinding; in fact, they 
are known in the trade as " grinding nutmegs." Certain insects devour 
the starchy endosperm, but avoid the resinous perisperm. We have 
seen kernels which had been visited by insects that lacked almost entirely 
the endosperm and were readily crushed between the fingers. Chemical 
analysis and microscopic examination showed an almost complete absence 
of starch, but an excess of resinous matter. 

The elements of ground nutmegs especially worthy of notice are the 
rounded starch grains (Fig. 454, am) with distinct hilum, often in twins, 
triplets, and larger aggregates; the oil cells, pale yellow even after 
treatment with caustic alkali; the primary perisperm with crystals; 
and the brown secondary perisperm. 

The adulterants include every imaginable cheap material which is, 
or may be made, brown in color. The materials which have been detected 
include nutmeg shells (spermoderm), cocoanut shells and other nutshells, 
cocoa shells, linseed meal, cereal matter, etc. 

Whole Mace. The dried arillus, like the nutmeg, is often used whole 
in the household. The characters of importance in diagnosis are the 
longitudinally elongated epidermal cells (Fig. 452, ep), cross-sections 
of which (Fig. 451, ep) are tangentially elongated; the amylodextrin 
starch grains (seen after extraction of the fat); and the light yellow oil 
cells, which do not become orange with alkali. As the blades are more 
or less broken, it is an easy matter to adulterate with mace from inferior 

Bombay mace (Fig. 457) has narrower blades, forming a dense 
tangle at the end of the arillus. If chewed, it sticks to the teeth, colors the 
saliva orange, and does not have a spicy flavor. Cross-sections show 
that the epidermal cells (Fig. 458, ep) are radially elongated. Treat- 


ment with alkali dissolves the dull-yellow contents of the numerous oil 
cells (/) to a blood-red liquid. The high percentage of non-volatile 
ether extract, as well as the deportment of the alcoholic extract toward 
reagents, also aids in diagnosis. 

Macassar or Papua mace is identified by the broad, dark-brown 
blades, the peculiar wintergreen odor, and the high percentage of fat. 
Unfortunately it cannot be distinguished with certainty from true mace 
by its microscopic structure. 

Ground Mace is a buff or brown greasy powder with an aroma resem- 
bling that of nutmegs, but more delicate. The noticeable microscopic 
characters are the amylodextrin starch grains becoming red with iodine, 
the elongated epidermal cells, and the oil cells. In detecting Bombay 
mace, the large numbers of oil-cells and the color of their contents before 
and after adding alkali are of chief importance, coupled, of course, with 
qualitative chemical tests and determinations of ether extract. Chemical 
analysis must be relied on to detect Macassar mace. Starchy matter, 
nutshells, and other foreign materials used as adulterants may usually 
be detected by the microscope. 

Nutmeg Shells have no real value but serve as an adulterant. The 
powder is identified by the enormously elongated palisade cells (Fig. 453, 
pal 2 ), and the detached fibers of the outer layer of the perisperm. 


See General Bibliography, pp. 671-674: Berg (3); Hanausek, T. F. (10, 16, 48); 
Mace" (26); Meyer, A. (27); Moeller (29, 30, 32); Planchon et Collin (34); Schimper 
(37); Tschirch u. Oesterle (40); Viliiers et Collin (42); Vogl (43, 45). 
Baillon: Sur Porigine du maces de la muscade et des arilles en generale. Comptes 

rendus de l'academie, 78, 779. Adansonia, 1876, 11, 329. 
Btjsse: Ueber Gewiirze. Muskatnusse. Arb. Kaiserl. Ges.-Amte. 1895, 11, 390, 628. 
Busse: Notez betreffend den Nachweis von Bombay Macis in Macispulver. Ztschr. 

Unters. Nahr.-Genussm. 1904, 7, 590. 
Hallstrom: Anatomische Studien tiber die Samen der Myristicaceen und ihre Arillen. 

Arch. Pharm. 1895, 233, 441. 
Hanausek, T. F.: Verfalschte Macis. Ztschr. Nahr. -Unters. Hyg. 1890, 4, 77. 
Moeller: Ueber Muskatnusse. Pharm. Centralh. 1880, 453. 
Morptjrgo: Delle Spezie. Trieste, 1904. 

Pfehter: Die Arillargebilde der Pflanzensamen. Inaug.-Diss. Berlin, 1891. 
Ranvez: Verfalschung des Muskatpulvers durch die Muskatschalen. Ann. Pharm. 

1900, 6, 139. 
Tschirch: Ucuhuba, die Samen von Myristica surinamensis. Arch. Pharm. 1887, 

66, 619. 


Tschirch: Inhaltsstoffe derZellen des Samens und des Arillus von Myristica jragrans 
Houttuyn. Tageblatt der 58 Versammlung deutscher Naturforscher u. Aertze 
in Strassburg, 1888. 

Voigt: Ueber den Bau und die Entwickelung des Samens und Samenmantels von 
Myristica jragrans. Inaug.-Diss. Gottingen, 1885, 365. 

Waage: Banda- und Bombay -Macis. Pharm. Centralh. 1892, 33, 372. 


Myristica argentea Warb. yields Macassar or Papua nutmeg and 
mace, products ranking next to true nutmeg and mace in importance. 
The nutmegs (Fig. 456), often known as long 
nutmegs, are 25-40 mm. long and 15-25 mm. broad, 
but by microscopical or chemical methods are not 
distinguishable from true nutmegs. The shell, as 
emphasized by Tschirch and Oesterle, lacks the 
fiber layer, a characteristic of no value in the dia- 
gnosis of the commercial product, as that is free 
from the shell. 

Macassar Mace is darker colored than true 
mace and has broader blades. In its microscopic 
Nutmeg" (Myristica structure and chemical reactions it is much the 

argentea) Natural same as true mace; in percentage composition, 
size. (Warburg.) > r o r- 

more like Bombay mace. It contains over 50 per 

cent of non- volatile ether extract, but less than 10 per cent of " starch." 


See General Bibliography, pp. 671-674: Moeller (32); Yogi (45). 
Also see Bibliography of nutmeg and mace p. 539. 
Waage: Papua-Macis. Pharm. Centralh. 1893. X. F. 14, 131. 


The chief adulterant of true mace is the arillus of Myristica Mala- 
barica Lam., known as Bombay mace. Although this product is obtained 
from a tree belonging to the same genus as true mace, it is nearly taste- 
less and has absolutely no value as a spice. The elongated nutmeg 
of this species does not come into Europe or America. 

Bombay mace has much narrower and more numerous blades than 
the true mace. These at the apex are vermiform, forming a tangled, 
conical mass (Fig. 457). The color is usually a deep red-brown, although 
sometimes it is yellow. 




Viewed in cross-setions (Fig. 458), the radial diameter of the epi- 
dermal cells {ep) is greater than the tangential, whereas in true mace 
the reverse is the case. So far as the cell-structure is concerned, this 
distinction is the most important, though it is not of use except in the 
examination of whole mace, or at least broken mace, having fragments 
large enough for cutting sections. Of greater value are the reactions 
of the material contained in the oil cells (/). Ex- 
amined in water, these cells are not only more nu- 
merous than in true mace, but the contents are of an 

Fig. 457. Bombay Mace 
(Myristica M a lab a - 
rica). Natural size. 

Fig. 458. Bombay Mace. Cross section of outer 
layers, ep epidermis; p parenchyma; / pigment 
cells; g bundle. (T. F. Hanatjsek.) 

orange-red color. On treatment with alkali the color dissolves to a 
blood-red liquid, whereas in the case of true mace the color is not 
greatly changed. 

Chemical Examination. 

Chemical analysis shows that Bombay mace contains nearly 60 per 
cent of non-volatile ether extract, or over twice as much as true mace, 
but only 15 per cent of " starch." 

Several qualitative methods of detection have been described, of 
which Busse found Waage's test and the capillary test the most reliable. 
The tests employing lead acetate and chrom alum are stated by the same 
author to be entirely unreliable, and those employing basic lead acetate 
(Hefelmann's test), iron alum and iron acetate were unsatisfactory. 
Waage's test consists in adding potassium chromate to the alcoholic 


extract (one part of mace to ten parts of alcohol). In the case of Bom- 
bay mace the solution becomes more or less blood-red and the precipitate, 
at first yellow, becomes red on standing. If only true mace is present 
both the solution and precipitate are yellow and do not greatly change 
on standing. 

In making the capillary test strips of filter-paper 15 mm. broad are 
soaked in the alcoholic extract for 30 minutes, dried, dipped in boiling 
saturated baryta water, and spread on clean paper to dry. Bombay 
mace gives a brick-red color, but true mace and Macassar mace, a brown- 
ish yellow, faintly red in the lower part of the strip. 


See General Bibliography, pp. 671-674: Moeller (30, 32); Tschirch u. Oesterle 
(40); Vogl (45). 

Also see Bibliography of Nutmeg and Mace, p. 539. 
Tschirch: Bombay-Macis. Pharm. Ztg. 1881, 556. 

CARDAMOMS {Zingiber acece). * 

The various plants yielding the cardamoms of commerce are all peren- 
nial, rush-like herbs, natives of southeastern Asia. 

Two varieties of this spice are exported; the small or Malabar 
cardamom, and the less important long or Ceylon variety. Although 
the plants producing these fruits were formerly regarded as separate 
species, both are now classed as Elettaria Cardamomum White et Maton. 
Rarely other varieties reach the markets of Europe or America, such 
as Siam or round cardamom {Antomum Cardamomum L.), wild or bas- 
tard cardamom (A. xanthloides Wall), Bengal cardamom (A. subulatum 
Roxb.), and Java cardamom (A. maximum Roxb.). 

The fruit is a three-celled capsule, often ending in a short beak, 
the remains of the perianth. Each cell contains two rows of closely- 
crowded seeds, each enveloped and cemented to its neighbor by a deli- 
cate transparent membrane, the arillus. The form of the capsule, its 
size and color, as well as the number and structure of the seeds, vary 


Malabar cardamoms are rounded triangular, more or less elongated, 
somewhat over 1 cm. long. The leathery pericarp is light brown, yellow, 



or nearly colorless, longitudinally striated, and only slightly aromatic. 
Colorless, membranous partitions separate the fruit cavities. The seeds, 
usually 6-8 in number, form a coherent mass, from which, however, the 
individuals, each enveloped by its delicate arillus, are easily separated. 
They are red-brown, 2-3 mm. long, irregularly angular, transversely 
wrinkled, and have a sunken hilum and a raphe in a groove running 
Tiearly the length of the seed (Fig. 459). A bulky perisperm surrounds 

Fig. 459. Malabai Cardamom (Elet- Fig. 460. Malabar Cardamom. / longitudinal 
(aria Cardamomum) . Seed with a section, X 3. II cross section, X 8. p perisperm; 

arillus. X3. (Luerssen.) e endosperm; em embryo. (Luerssen.) 

the endosperm and this in turn the minute embryo (Fig. 460). 
odor is agreeably aromatic, suggesting camphor, the taste biting. 



The Pericarp when dry is less than 1 mm. thick, but swells some- 
what in water. Cross- and tangential-sections are cut either wet or dry; 
surface preparations of the outer and inner layers are obtained by scraping. 

Fig. 461. Malabar Cardamom. Outer layers of shell (pericarp), ep epicarp, p parenchyma 
with h resin cells. X160. (Moeller.) 

i. Epicarp (Fig. 461, ep). The rounded polygonal cells often show 
marked evidence of their formation by the division of mother cells. 
2. Mesocarp (p). A thin-walled, large-celled parenchyma forms the 



ground tissue, in which are numerous smaller cells containing lemon- 
yellow or red-brown resin lumps (50 /t). The nbro-vascular bundles 
have thin- walled spiral vessels (60 //), and 
moderately thickened bast fibers of about the 
same diameter as the vessels. In the inner 
layers the tissue is a spongy parenchyma 
(Fig. 462). 

3. Endocarp (Fig. 462). The cells are 
usually longitudinally extended, but some 
times are irregularly arranged. 

Fig. 462. Malabar Cardamom. Inner layers of shell Fig. 463. Malabar Carda- 
(pericarp) showing spongy parenchyma and endocarp. mom. Arillus in surface 
X160. (Moeller.) view. X160. (Moeixek.) 

Arillus (Fig. 463). The membranous, colorless seed-mantle covers 
the seed loosely and is attached to it at the base. At first glance it appears 
structureless, but on careful observation we see that it is composed of 
several layers of delicate, greatly elongated cells, containing strongly 
refractive drops and here and there crystals, either singly or in rows. 

Spennoderm (Figs. 464 and 465). To cut sections it is necessary to 
have the hard seed firmly fixed either between corks or embedded in 
hard paraffine. The first and fifth layers are highly characteristic. ' 

1. Outer Epidermis (0). This layer, like several already described, 
has longitudinally extended cells, but here they are very striking, because 
of their thicker walls, sharp outline and frequent arrangement side by 
side. The cells are mostly 35 p. broad and have either pointed or blun*- 


2. Cross Cells (qu), often with brown contents giving the reactions 
for tannin, are indistinctly seen in cross-section, more readily in surface 

3. Oil Cells (oil). These are large, thick cells containing the essen- 
tial oil, present in the fruit to the amount of 4 per cent, and also other 

4. Parenchyma (p). One or two layers of cells are seen in cross- 

Fig. 464. Malabar Cardamom. Cross section of arillus and seed, ar arillus; spermo- 
derm consists of outer epidermis, qu cross cells, oil oil cells, p parenchyma and st 
palisade cells; perisperm consists of al aleurone cells and am starch cells. (Moeixer.) 

section after swelling with reagents. In surface view they are readily 

5. Palisade Cells (st). Because of the enormous thickening of the 
walls and their intense brown color, these cells form the most character- 
istic layer of the entire fruit. So greatly are the walls thickened that 
only a tiny cavity, at the outer end of each cell, remains. This cavity 
contains a crystal-like body. The cells are 8-20 fi broad and about 
25 ft high. Focusing on the outer wall, the cells appear moderately 
thin-walled, much thinner than the corresponding cells of Ceylon carda- 
mom; but focusing on the inner wall, no lumen is evident, only a com- 
pact brown mass with the sharply defined outline of the cell. 

Perisperm. The outer layer contains aleurone grains, the remaining 
cells starch grains. The latter are minute, usually 2-3 /< and seldom 
over 4 fi, rounded or polygonal, and, like pepper and buckwheat starch, 
form dense masses conforming in shape to the cell. In the center of 



each mass is a hollow space containing a large crystal or several small 
crystals of calcium oxalate. After treatment with cold alkali, although 
the starch dissolves, the masses do not disappear, but form at first a 
granular, later a homogeneous mass, indicating the presence of a material 
in which the starch grains are embedded. 

The Endosperm is relatively small and contains in its small, thin- 
walled cells aleurone grains and fat but no starch. 

The Embryo has been carefully studied in various stages of growth 
by Tschirch, who found that it consists of an axially arranged absorptive 

o — 


gu — 

Fig. 465. Malabar Cardamom. Elements of seed in surface view, o outer epidermis; 
qu cross cells; ^parenchyma; st palisade cells; e perisperm; am starch cells. X160 

organ, surrounding at its basal end a minute plantlet which shows before 
sprouting little differentiation. The cells are small and contain the 
same materials as the endosperm, namely proteids and fat. 


Malabar or small cardamoms serve as a spice, especially as an ingre- 
dient of curry powder, and also in the making of various aromatic pharma- 
ceutical preparations. For these only the seeds should be employed, 
as the shells contain little or no essential oil. It is, however, difficult to 


effect a complete separation, and commercial cardamom seeds invariably 
contain a certain amount of shell fragments. In the case of the ground 
seed, the presence of a large amount of shells indicates willful adultera- 

Many fragments found in the ground seed have distinctive characters. 
Of the perisperm elements, the masses of minute starch grains offer an 
excellent means of identification. The characteristic tissues of the sper- 
moderm are the elongated epidermal cells (Fig. 465, 0), often with adhering 
cross cells (qu), and the brown mosaic of palisade cells (st). The epidermal 
cells have the same form as the inner epidermis of the pericarp and the 
cells of the arillus, but have much thicker and more rigid walls. The 
elements of the pericarp worthy of especial notice are the yellow or brown 
resin masses. 


See General Bibliography, pp. 671-674 Berg (3); Greenish (14); Hanausek, T- 
F. (16); Hassall (19); Meyer, A. (10, 27); Moeller (29, 30, 31, 32); Planchon et 
Collin (34); Schimper (37) ; Tschirch u. Oesterle (40); Villiers et Collin (42); Vogl (45). 
Bttsse: Ueber eine neue Kardamomen-Art aus Kamerun. Arb. Kais. Gesundh. 1898, 

14. 139- 

Hartwich und Swanxund: Ueber Kardamomen von Kolombo, das Rhizom von 

Zingiber Mioga und Galanga major. Ber. deutsch. pharm. Ges. 1903, 13, 141. 
Morpurgo: Delle Spezie. Trieste, 1904 
Niederstadt: Die im Handel vorkommenden Cardamom-Arten. ' Chem.-Ztg. 1897, 

21, 831. 
Schade: Entwicklungsgeschichtliche Untersuchungen iiber die Malabar-Cardamomen 

und vergleichend-anatomische Studien iiber die Samen einiger anderer Amomum- 

und Elettaria Arten. Inaug.-Diss. Bern, 1897. 
Soltsien: Verfalschung von Cardamomenpulver. Pharm. Ztg. 1892, 373. 
Tschirch: Beitrage zur Pharmakobotanik und Pharmakochemie. Schw. Woch. Chem. 

Pharm. 1897, No. 17. 
Tschirch: Ueber Cardamomen. Schw. Woch. Chem. Pharm. 1897, 35, 481. 
Tschirch: Diagnose der Cardamomen. Schw. Woch. Chem. Pharm. 1897, No. 43. 
Waage: Fructus Cardamomi. Ber. pharm. Ges. 3, 162. 


Long or Ceylon cardamoms are the fruit of a variety of Elettaria 
Cardamomum White et Maton, which is still classed by some as a dis- 
tinct species. 

The capsules are much longer than those of the Malabar variety, 
often reaching 4 cm., and the seeds, of which there are about 20 in each 
of the three cells, are twice as large, but are less aromatic. 



Of the several distinctions from Malabar cardamoms, the presence 

* — 

FlG. 466. Ceylon Cardamom (Elettaria Cariamomum). Epicarp with hairs and hair 
scars in surface view. X160. (Moeller.) 

Fig. 467. Ceylon Cardamom {Ekttaria Cardamomum). Tissues of inner pericarp in 
(Mo V1£ T' Wlng P arenchvma . spongy parenchyma and endocarp (<•/>). X160. 

of hairs on the epicarp deserves first mention (Fig. 466). It is true 



that these are seldom found on the commercial product, but the scars 
with radiating cells about them are quite as useful in diagnosis. The 
outer epidermis of the spermoderm 
(Fig. 468, 0) has much thicker walls 
(double walls 6 /i), than in the Malabar 
species, although the cells themselves 
are narrower. Other differences are 
too slight to be of practical use. 


( Umbellifercs) . 

The inflorescence of the plants 
belonging to the Umbellijerce is in 
flattened heads or umbels, a word de- 
rived from the Latin umbella, mean- 
ing umbrella. The flowers are small 
with two-celled ovaries crowned by $-* 
five petals, five stamens, and usually 
five minute calyx teeth. The two 
carpels, or mericarps, are plano-con- 
vex, joined On the inner flattened side FlG : 4^8. Ceylon Cardamom. Tissues 

' J of spermoderm in surface view, o outer 

known as the commissure. On the 

epidermis; , st palisade cells. 


convex or dorsal side they bear five 
primary ribs and sometimes four secondary ribs. When ripe the 
mericarps readily separate, disclosing the carpophore or prolongation 
of the stem to which the carpels are attached at their upper ends. In 
cross-section the mericarps are either semicircular or kidney -shaped. 
Running longitudinally through the dry pericarp, are brown, essential 
oil ducts or vittm, which are evident to the naked eye both in cross-sec- 
tion and, after boiling with dilute caustic alkali, in surface view. 

The epicarp is either smooth or hairy, the hairs being unicellular 
(anise) or multicellular (cumin). 

The mesocarp has outer and inner parenchymatous layers, between 
which is a middle zone traversed by the fibro-vascular bundles of the 
ribs, and by the oil ducts, the latter being jointed and encased in a single 
layer of parenchyma. The ground tissue of this middle zone is largely 
parenchymatous, except on the dorsal side of coriander fruit, where it 


forms a dense sclerenchyma layer. The cells of the inner layer of the 
mesocarp are either isodiametric or transversely elongated, conspicuous 
or indistinct. 

The endocarp cells are, for the most part, transversely elongated, 
forming a cross-cell layer, although in some species groups of cells extend 
in other directions, giving the layer a parqueted appearance. In breadth 
the cells differ greatly according to the species. 

The anatropous seed consists of a thin spermoderm, usually of one 
distinctly cellular layer and of several obliterated layers, a bulky endo- 
sperm and a minute embryo embedded in the upper end of the endo- 
sperm. Aleurone grains 2-15 [i in diameter, containing crystal rosettes 
of calcium oxalate, or globoids, also fat, are the only -visible contents of 
the endosperm. The minute radicle of the embryo is directed upward. 

The fruits contain essential oils, which give them their value as flavor- 
ing materials for food products, or in medicine. 


Pericarp. Epicarp Cells marked with delicate striations. Unicell- 
ular, warty hairs in anise; prickles (emergences) in cumin; papillae 
more or less evident in celery. Epicarp smooth in all the other species. 

Mesocarp. Ou^- ^yers parenchymatous in all the species and not 
distinctive. Middle layers of coriander on dorsal side composed of 
sclerenchyma tized fibtis with bundles but without oil ducts. In all 
the other species the ground tissue is parenchyma, through which pass 
bundles and oil ducts. 

Oil Ducts. One in each groove in fennel, dill, caraway, and cumin; 
one to three in celery; three to six in anise. 

Ribs of each fruit uniform, except in dill, where the lateral ones have 
wings of sclerenchyma cells perpendicular to the bundles. 

Reticulated Cells accompany the bundles of fennel and dill. 

The Inner Mesocarp pronounced in fennel, dill, celery, and coriander; 
inconspicuous in the other species. In coriander, cell-walls thickened, 
those of innermost layer porous; cells of inner layer in celery transversely 
elongated, broader than those of endocarp, more or less parqueted. 

Endocarp cells narrow (mostly less than 7 /<) in fennel, dill, celery, 
and coriander; broader (mostly over 7 /x) in caraway, anise, and cumin. 
€ells parqueted in fennel, dill, and celery. 


Spermodenn. Much the same in all species. Outer layer of isodia- 
metric or transversely elongated cells. Inner layers of obliterated cells. 

Endosperm. Walls thick. Cell-contents fat and aleurone grains 
3-15 (i, containing oxalate crystals or globoids. 

Embryo minute, of no diagnostic value. 

Carpophore and Stem of woody elements. 

Analytical Key to Umbelliferous Fruits. 

I. Ground tissue of mesocarp parenchymatous throughout, or sclerenchymatized near 

the bundles only. Oil ducts on both dorsal and commissural sides. 
(a) Endocarp cells mostly less than 7^ broad, often parqueted. 
* One oil duct in each groove. 

1. Ribs of uniform size Fennel. 

2. Lateral ribs with wings Dill. 

** One to three oil ducts in each groove. 

3. Ribs and bundles small, inner mesocarp of transversely elongated cells. 

(J) Endocarp cells mostly more than 7/1 broad, seldom parqueted. 
■ * One oil duct in each groove. 

4. Epicarp smooth ., Caraway. 

5. Epicarp with emergences Cumin. 

** Several oil ducts in each groove. 

6. Epicarp with warty unicellular hairs Anise. 

II. Middle layers of mesocarp on dorsal side strongly sclerenchymatized. Oil ducts 

present only pn commissural side. 

7. Inner mesocarp thick -walled and porous. Endocarp cells mostly less than 

IP broad Coriander. 


Baetsch: Beitrage zur Entwicklung d. Umbelliferenfriichte. Diss. Breslau, 1882. 
Kayser: Ueber das Verhal