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VG Vane à: UNE it ee a 7 Py jai ny Tu ae rel ii, ARE ges Pee RN a As Raddy | Ps Ads al L'ILE A! { i Ally 12 ik oe Aas Hea) Le ahaa Mad, | 1-0 i a nt Tht 7 LA OA ee NRA Li is Bas (A DE yeh es DE METRE “i 7 à. a Ro \ a) LA PASS WTA : à | “Ay 7 i ey, AE LUN ( LOE hos cliyie a at MN À ; 4h ny. | PA i oY Ne 4 ! { LA pe A 5 Be a à A : win Nias si i Avs mn PAR hoe aa = à PR AURe ‘ D ee, A Che CET 7h ! al FC re ¥ Ai Ke iy a ey eee tages LAN UE Ratio Vag UE NE Al AURA Mey ey ia Fy OBSERVATIONS 2, ON THE STRUCTURE OF FRUITS AND SEEDS; TRANSLATED FROM THE ANALYSE DU FRUIT M. LOUIS-CLAUDE RICHARD, NEMBER OF THE INSTITUTE OF FRANCE, PROFESSOR OF BOTANY IN THE ECOLE DE MEDECINE AT PARIS; AND FOREIGN MEMBER OF THE LINNEAN SOCIETY OF LONDON : Comprising the Author’s latest corrections; and illustrated with Plates and Original Notes by OTE EIN: SATIN, D: Ye: LONDON; JOHN HARDING, ST. JAMES’S STREET, AND WILKIN AND YOUNGMAN, NORWICH. 1819. : WILKIN AND YOUNGMAN, PRINTERS, NORWICH. TO WILLIAM JACKSON HOOKER, ESQ. FELLOW OF THE ROYAL, LINNEAN, AND ANTIQUARIAN SOCIETIES, AND MEMBER OF THE WERNERIAN SOCIETY OF ss EDINBURGH ; = THE FOLLOWING SHEETS 4} ARE MOST RESPECTFULLY INSCRIBED BY HIS VERY GRATEFUL AND Le AFFECTIONATE FRIEND J. LINDLEY. PREFACE. AMONG the number of elementary works which have issued from the English press within a few years, it is to be lamented that not one should have appeared, which is at all equal to explain one of the most important parts of Botany, the structure of Fruits and Seeds. This is a circumstance which is the more to be regretted, since an intimate acquaintance with that division of the science, is of the utmost consequence, not less in a practical than a philosophical point of view. vi The Philosophia Botanica of Linneus is more perfect than could have been expec- ted, from the progress science had at that time been able to make; but the mighty mind ofits immortal author had to struggle with difficulties which would have over- whelmed a genius less powerful than his own. The Augean stable was again to clear; in the short space of half a century, the rubbish and the building were removed together, and anoble superstructure raised in their room. With such veneration on this account have the followers of Linnzus been inspired, that his productions have been considered sacred, and it has been held almost profane, either to suggest amendments of his system, or to expose defects in his works. His Phelosophia has afforded most of the materials of every publication of a similar nature which has since appeared among his followers, who have suffered themselves by this predilec- vi tion in his favour, to overlook the rapid strides of the science in another quarter. To such lengths indeed have some proceed- ed from their desire to uphold the sexual system, as even to attempt to conceal the important improvements of the method of his great opponent. The Naturat ORDERS of the great Jussieu have this important advantage over the system of Linnæus, or any other system whatever, as far as regards natural arrangement, that their characters are not confined to any one part of the fructification. They require that the most scrupulous attention should be given to every modification of the organs of repro- duction. This it is which has occasioned the discovery of the most beautiful truths, which has opened the way to the most in- teresting fields of observation. By it the mind is kept perpetually in action, the ideas are extended, the sphere of compre- hension is enlarged, and admirable oppor- B 2 Vill tunities are afforded for contemplating nature in her most bewitching form. Although, as has been already observed, the characters of NATURAL ORDERS are confined to no particular part of the fructi- fication, yet experience has shown that the organ which contains the rudiment of a plant is usually one of the most impor- tant for combining natural groups in their perfect state. To this therefore the most unwearied attention has been paid ; and it is hoped that the little Analyse du Fruct of M. RicaarD will afford young botanists the opportunity of studying the principles of Carpology, without having to experience such difficulties as have hitherto presented themselves. The necessity of the additions which have been made, will be best explained by an account of the circumstances under which the original was published. è 1X M. Duval, an intimate friend of M: Richard, and to whom the scientific world must be for ever indebted, had for several years attended the lectures delivered by the learned Professor at the Ecole de Médicine at Paris, and had carefully preserved me- moranda of them, any defects in which his personal intimacy with M. Richard enabled him to supply. ‘Every botanist” observes M. Duval in his preface “who is acquaint- ed with our laborious Professor, knows that he has amassed a great quantity of obser- vations from which he one day intends to deduce the fundamental laws of botany. They all know that these are to be accom- panied by figures drawn by his own hand with the greatest care. Every one inter- ested in the progress of our science, must anxiously look for the publication of so useful a work. But the unfortunate situa- tion of M. Richard: the ill success of his repeated applications to Government for X assistance : the resolution he has taken to publish nothing unless he possesses the pecuniary means of engraving his draw- ings: such are the motives for a delay which is the more distressing as the length of it is uncertain. Perhaps it may be accel- erated by a successful execution of his plan of selling all he possesses except what re- lates to botany! Itis the last effort he can possibly make for defraying the expence of engravings and consequently of publishing his observations.” For the use of botanists till this great work could appear, M. Duval undertook the publication of that part of his lectures, which immediately related to the structure of fruit and seeds. Eleven years have now elapsed and this little Pro- dromus is all that has appeared, except a few memoirs in the Annales du Muséum. Every one will immediately perceive that although the observations of the Professor x1 would be perfectly clear when delivered by himself, and explained to his hearers by examples before them ; yet to those begin- ners who are deprived of such advantages, many things would become dificult to comprehend, and from want of previous acquaintance with the subject, even unin- telligible. To remedy as far as possible this defect, illustrative notes and figures have been added. The latter have been drawn by the editor with the utmost care, but no more details have been introduced than were absolutely necessary, as they would have encreased materially the ex- pence of the publication. When the sub- jects themselves could not conveniently be procured, recourse has been had to the figures of others, but never without ac- knowledging it. The translation, as far as the different idioms of the two languages would possi- xu bly admit, has been scrupulously formed on the model of the original. It is hoped that the evident necessity of this, from the peculiar nature of the subject, and the edi- tor's inexperience in the literary field, will serve as an excuse for the numerous defects of the work as a piece of composition ; if he has at any time failed in explaining the meaning of his author, he must endeavour to shelter himself under the protection of the adage, in magnis vel voluisse sat est. He, however, thinks it necessary to observe that he is by no means answerable for all the opinions which the following sheets may contain: their learned author is fully prepared to support them, and on him must that duty fall. It is to be regretted that so many new terms should have been substituted for old ones, which, if not quite so expressive, were at least better under- stood, and from their right of priority should have been retained. To remedy xiil this in some degree, the synonymous terms of Gærtner have been added in the notes. From the hasty manner in which the ori- ginal was published, (in seven days, ) it un- avoidably contamed many particulars which later observation has made it neces- sary to alter. This has been effected par- tially, by the distribution of corrected copies, to a few select friends. Some pas- sages, however, still remained, the inter- pretation of which did not appear to be entirely satisfactory; the interest which Mr. Hooker has taken in the publication, in- duced him to propose them to M. Richard for more precise explanation; with his usual liberality, he not only immediately complied with the request, but communi- cated all the corrections which ten years’ additional experience has induced him to make; these have been incorporated with the work, and give the present edition some xiv additional and important claims on the attention of the public, as containing the Professors latest views of the subject. The Primaria plantarum divisio has been inserted at the end by M. Richards particular request. The following letter to M. Duval will throw some additional light on the princi- ples which M. Richard has exposed in the body of the work : SIR, I have carefally perused the abridgment of my lectures on the structure of fruit, which you think of publishing. As I find nothing in it which disagrees with what I have said and cbserved myself, [ adopt it entirely and authorize you to give it to the public. The errors it contains, for I cannot flatter myself that I have avoided them in so difficult a department of the science, must be attributed to me. XV Some readers will exclaim against the intro- duction of so many new terms, but others will perhaps be found to adopt them ; especially when it is remembered that if the work of Gærtner has not been so much applied to the improvement of generic and ordinal characters as it might have been, the cause may be found in the want of terms to express with brevity the observations of that learned carpologist. This partial sketch which you are about to publish of a greater work, will shew that I have laboured to diminish this inconvenience. Indeed I cannot refrain from demonstrating, by only a few examples, that the new terms I propose, may be employed to ad- vantage in compressing the characters of the fructification of natural orders into a small compass. ENDORHIZÆ. L.— Embryone epispermico. Potamophilæ seu Fluviales. Achenium subdrupaceum : Sem. appensum sive inver- sum: Emb. antitropus. Joncagineæ. Sem. unicum aut pauca, erecta: Emb. ortho- tropus. Alismacee. Sem. erectum, aut duo ascendentia : Emb. homotro- pus, hippocrepicus. Butomee. Sem. plura, parietalia, ascendentia : Emb. homotro- pus, rectus aut hippocrepicus. XVI If.—Embryone endospermico. Graminez. Caryopsis rard Achenium: Sem. subascendens: Emb- extrarius, obliquè sublaterali-basilaris, hete- rotropus, macropodus. Cyperaceæ. Achenium sæpius subdrupaceum: Sem. erectum: Emb. intrario-basilaris, orthotropus, brachypo- dus. Typhinee. Achenium drupaceum: Sem. inversum: Emb. axilis, orthotropus. Nevertheless I am far from supposing that my carpological labours have made great advances towards perfection. The progress of the Philoso- phical part of a science of observation is necessa- rily slow and successive. Its end is concealed in an unbounded futurity; to arrive at it is im- possible ; to diminish its distance a little is all that the most ingenious and most enthusiastic mind can desire. Ishall be happy if I succeed, before my death, in adding fresh light to that with which my predecessors have illumined the dark and difficult road of fundamental Botany. But in an ‘age when the size of a work, its typographical elegance and the seductive beauty of its figures are the best guarantees of the talents of the Botanical writer, what kind of fate may this little book expect, which has nothing of that xvil sort to recommend it to the notice of those who may determine on its reputation ! [confess, Sir, that these reflections have hitherto had no little effect in deterring me from venturing on the pub- lication of extracts, which, from their want of attractions and support, would always tend to sink in the obscurity from which they sprang. Yet the present may be useful to students who attend my course. Why not add to this first mo- tive of publication, the hope of seeing it noticed by Botanists of celebrity! In such a matter the approbation of a chosen few is to be preferred to the commendations of the multitude. The praise of a few truly learned men will encourage me; their just criticisms will assist me. Some one of them may perhaps be induced, by the perusal of this tract, to allow that I have used some exertion by my public lectures to contri- bute to the progress of science, and may pencil my name on the margin of the report which the Institute has presented to His MAJESTY, RICHARD. CONTENTS. Or THE PERICARP. Epicarp, Sarcocarp, & Exdocarp, Cells, - - Dissepiments, - Trophosperm, & Podosperm, Dehiscence, & Axis, Unity or plurality of Pericarps, Parts falsely attributed to the Seed, Naked seeds, OF THE SEED, - Episperm, - Hilum, - - Base, - - Summit, - - AXIS, - - =< Face, back, sides and edges, Annexion, - Direction, erect, inverted, suspended, ascending, peritropal, reclined. Kernel, - - Endosperm, - - xXIX Page. OFTHE EMBRYO, - - - - - - - - 26—34 Direction, pericarpic, spermic, homo- trepous, orthotropous, antitropous, 34—37 heterotropous, amphitropous. Pet 2) oh ANNE eR = 88 Cotyledon, Cauliculus, & Gemmule, - - 39 Or EXEMBRYONATÆ, - - - - - - - - 40 Sporules, - - - - - - - - - - 41,43 Or EMBRYONATÆ, - - - - - - - - - 43 Endorhizæ, - - - - - - - - - - 43 _ Exorhizæ, - - - - - - - - - - - 44 Or ENDORHIZÆ, - - - - - - - - - - 46 Difference between their radicle and cotyledon. 47 Embryo, 47. ÆEpispermic, Endospermic - - 50 Vitellus, 51. in Ruppia 52, Hydrocharis 53, Zostera 54, Nelumbium 55, Nymphozan- thus 56, Nymphea 58, Graminee, - - 58 Spilum,) --4-4 = 20205) ils 2 - - 58 Blastus, Hypoblastus, & Epiblastus, - - - 59 Remarks on the preceding genera, - - - 62 GERMINATION OF ENDORHIZÆ, - - - - - 67 Developement of the radicle, - - - - - 68 of the gemmule, - - - - 69 Genera to be excluded from Endorhize, - - 70 Or EXORHIZE, - = -'- -'+ - -,- 71 Monocotyledonous, - - - - - - - - 71 Dicotyledonous, - - - - - - - - - 72 Structure of Lamia, Cycas, Hippocas- tanum, Castanea, Tropeolum, ‘oo Considerations on the above, - - - - - 77 Polycotyledonous, - - - - - - - - 79 ERRATA. Page 23, line 12 for COMPOSITE, read COMPOSITÆ. 56, 24 — Nymphea, read Nymphea. « 56, —— 27 — Nuphar, read Nymphea. 56, —— 29 — And, read Nuphar. 57, —— 27 — NYMPHEACE, read NYMPHÆACEÆ. BOTANICAL ANALYSIS OF FRUITS. Every Fruit is essentially composed of two principal parts, which are the Pericarp and the Seed, Or THE PERICARP.—The Pericarp is that part which determines the exterior form of a perfect fruit, and in which the seed is immediately and entirely enclosed. Since it is only the ovarium in an advanced state, it ought to indicate on some point of the surface, most frequently at the summit, traces of the style or stigma; and this is the chief charac- ter which enables us to distinguish the Pericarp from certain coverings which have sometimes usurped that name. Every Pericarp is formed by a parenchyma- tous substance, traversed by vessels: but as it B 2 is impossible that the vascular system of an organized body can be naked, this parenchyma- tous substance is covered on the outside by the Epidermis and on the inside by the internal parietal membrane. I propose naming the epidermis of fruit ÆEpi- carp, the parenchyma Sarcocarp—and the inter- nal lining which forms the seminiferous cavity, I would call Endocarp.* The epicarp is frequently formed either en- tirely or in a great measure by the tube of the calyx, whose parenchyma is then incorporated with the sarcocarp.! The union of the calyx with the pericarp is recognized in this, that the latter is surrounded at a distance greater or less from the origin of the style or stigma by the salient edge of the calyx, or by a scar occasioned by its fall. The endocarp is always membranous; but it 2 For example in a Peach, the wooly outer integument is the epicarp, the fleshy part which is eaten is the sarcocarp; and the bony covering in which the seed is enclosed is the endocarp united with an indurated portion of the sarcocarp ;—this is better known by the name of Pufamen. b An example of this is found in the common Apple.—see tab. 1. fig. 1. where ais the fleshy tube of the calyx—b, the point where the sarcocarp unites with ia the sarcocarp itself—d, the endo- carp.—see also tab. 2. fig. 4. where the same letters represent the same parts in Thesium alpinum. It is hardly necessary to observe, that such a formation can only take place in fruits which for conve- nience are called inferior, though this explanation of their structure shews them to be superior, ©. D may be enlarged externally, by some portion of the sarcocarp differing in size and in hardness. When this portion of the sarcocarp acquires a bony * or woody texture, it forms what is termed anut, and nuculæ, when there are more than one. These nuculæ which characterize the kind of fruit I call Nuculanium, are much more frequent than is supposed by botanists, who usually mistake them for seeds. Perhaps they may be considered as the wood of the fruit; but this ligneous part arrives at considerable hardness much more rapidly than the wood of the stem, and it sometimes is the only woody part about the plant which bears it, The cavity of the pericarp that contains the seed, is defined by the endocarp. If the endo- carp be every where continuous, or be only in- terrupted by one or more distinct seminiferous processes, then the cavity of the pericarp is simple and it is unilocular.” If the endocarp itself form processes which unite by their inner edge in such a way as completely to divide the inside of the pericarp into several partial cavi- ties, the pericarp then becomes multilocular,‘ These cavities take the name of cells and the plates which divide them, that of dissepiments,* a As in Prunus and all drupaceous fruit. b See tab. 1. fig. 4. ¢ See tab. 1. fig. 3. d Thus in tab. 1. fig. 2. a is one of the dissepiments—e is a cell. In fig. 3. a, dissepiment—b, cell. B 3 4 Every true dissepiment* is made up of two iamelliform processes of the endocarp, placed back to back, and united to each other by a very deli- cate elongation of the sarcocarp. Since the origin of the dissepiments of every sort of peri- carp is the same, we must consider as erroneous the simple marginal application, either external or internal, that some botanists have attributed to that part in certain capsules," It is the same of dissepiments formed by the introflexed margin of the valves,° . Some pericarps (those of certain CRUCIFER, CucURBITACE&, HypDROCHARIDE#, &c.) are divided internally by false dissepiments which a The endocarp of each cell turns inwards at the place where it meets that of the other cell; the two endocarps become united, ands extending as far as the axis, form the dissepiment, Whatever be the number of cells, such is always the origin of the dissepiments,— Note communicated by M. Richard. b It sometimes happens that a pericarp opens into two valves op- posite the dissepiment, so as to separate from the latter, which retains its position, This is caused by the two endocarpic plates of the cells being ruptured with the rest of the pericarp; the two portions of the plates which form the dissepiment still preserving their cohesion, It is therefore evident that the expression ‘ dissepimentum “marginibus valvarum circumappositum” employed by Jussieu and his followers (vid. Juss. Scrophulariæe,) is not strictly correct. This sort of de- hiscence is what I call septifragal, Rich. Mss. See tab, 3. fig. 4. c Some pericarps open by the middle of the dissepiment, so as to divide it into two plates, each of which comes away with the valve to which it belongs. Since these plates are only extensions of the endocarp, and not of the same thickness as the valves themselves, bo- {anists are wrong in saying “ dissephnentum a valvarum marginibus introflexis’. I call this sort of dehiscence septicidal. Rich. Mss, See tab. 2. fig. 8. Ix D) existed even in the ovaria.* They are known, first, because they are not formed by the endo- carp, properly so called ;—secondly, because they most generally answer to each stigma, or to each division of the stigma; whilst the true dissepiments usually alternate with them. It results from what I have said, that the fruit of HYDROCHARIDEÆ, NYMPHEACEZÆ, CUCURBI- TACEÆ, &c, has as many cells as seeds. The internal structure of a pericarp, is essen- tially indicated by that of the ovarium of the plant which produced it.» What a host of errors have been committed by botanists from neglecting this important law! What seeming discordance between the fruits or certain neigh- bouring genera, and even of some natural orders, (JASMINE for instance) in which the ovarium have all an internal uniform structure! It is by the comparison of the perfect fruit with the ova- rium, that we are able more easily to recognize the true loculation of fruit, either incomplete or pulpy; and above all of those that are Pseudo- multilocular or cellular—among others the chief part of ANNONACER, a See fab. 1. fig. 5. A. This sort of false dissepiment M. Rich- ard considers to be only an extension of the trophosperm. b On account of the frequency of abortion of some of the parts. The ovarium of the Oak for example has three cells and six ovula—the acorn has never more than one seed. Here then two cells become entirely abortive and one ovulum in the other cell. 6 I substitute the name of Trophosperm for that of Placenta, which botanists have given to the internal part of the pericarp, on which the seeds are immediately attached.* Every visible process of the trophosperm which bears a single seed is known by the name of umbilical chord, (a name just as improper as the preceding,) for which I shall adopt that of Podosperm.! When the summit of the podosperm forms a protuber- ance or an expansion manifestly extended on the seed beyond the margin of the hilum; this protuberance or expansion, usually fleshy, con- stitutes the true arillus which is seldom de- veloped before fecundation.© Since the tro- phosperm has an immediate communication with the sarcocarp, the endocarp is always pierced or interrupted at that point where the trophos- permic substance penetrates or projects iuto the seminiferous cavity.4 Thus the scar or hollow a See tab. 1. fig. 6. a. b See tab. 1. fig. 5. B. b. c See tab. 2. fig. 10 and 11. where a is the podosperm—b the arillus wrapping up the seed in the shape of a fleshy, loose, red bag—at c the seed is seen appearing beyond the arillus--in Euonymus Europæus. The mace of the nutmeg affords another instance of an arillus, d Whena central trophosperm falls or is detached, the dissepi- ment exhibits a hole or scar at the place which it occupied, be- cause the endocarpic plate is always interrupted or perforated by the matter of the trophosperm, that is, the substance which bears the seeds. Rich. Mss. The importance of this is explained by the following observa- tion of M. Richard ; “ Carefully examine the interior of the capsule of Papaver; the sudden interruption of the endocarp towards the origin of each pro- jecting plate decides that these are so many trophosperras, and not dissepiments.” 7 made on some part of the endocarp, by the spontaneous separation of the seed, or of the trophosperm, assists us in discovering their true position, when the former are loose in the pe- ricarp, or even when they have been taken from it.* The trophosperm of a multilocular pericarp re- sults from the meeting and union of the paren- chyma of the dissepiments; when this leaves that edge of the latter which is next the axis, it ex- pands to the right and left, so that the parti- cular trophosperm of each cell is made up of the parenchyma of two dissepiments. The sutural or parietal trophosperm of an uni- locular pericarp is also produced by the con- fluence of the parenchyma of the two sides ; and to this almost universal mode of formation of each trophosperm, is to be attributed the frequent disposition of seeds in two ranks, and the common mode of dehiscence by the middle of trophosperms which are immediately parietal. The base of a pericarp is indicated by the a The seeds of a pericarp in a dry state are frequently loose or detached. If the surface of the endocarp be examined, a scar will be observed, or a hole or some sort of interruption which indicates the point where the seeds were attached. Rich. Mss, 8 centre of its point of attachment, or by that ex- tremity which is nearest its pedicel.* Its summit is equally determined by the point of origin of the style or sessile stigma,” The want of a real axis named Columella is supplied by an imaginary axis, by which is to be understood a line supposed to traverse longitu- dinally the middle of the whole mass of the pe- ricarp, from the centre of the base to that of its summit. Many pericarps are indehiscent; that is to say never open after maturity.{ Ruptures which burst irregularly, Orijfices, which gape by an opening either at the summit or the side, without denticulations,’ and those which are perforated at the top, or lateszally,® are very rare. Care must be taken not to confound the true rupture of the whole substance of the pericarp, with spontaneous excoriation, which does not open the endocarp,”" nor with the a In tab. 1. fig. 6, the base of the pericarp is pointed out by the letter b. b See tab. 1. fig. 5. À. a. © See tab. 2. fig. 8. where the summit of the Columella is seen above the valves at a. a See tab. 1, fig. 7. e Asin Momordica, Kiggelaria, Ryana, Xc. f See tab. 1. fig. 10, Reseda alba, also Colutea, Xc. & See tab. 1 fig. 9, 11. Antirrhinum, Campanula. b See tab. 3. fig. 2. Euphorbia. 9 cracking of the latter, which does not answer to the valvation of the sarcocarp. Divisibility, by which a pericarp separates into one seeded, and several closed divisions, is sufficiently common.* Solubility, by articula- tion, borders upon this, but is much more uncom- mon.’ When a seed bends back suddenly in a direc- tion contrary to its podosperm which is sensibly elongated, it is reclined by its proper direction ; but its direction with relation to the pericarp is indicated by that of the podosperm. Thus the seed of PLUMBAGINE#, Rhus, Pistacia, &c. is reclined ; but it ought to be considered erect, as to the pericarp, because its podosperm is fixed to the bottom of the latter. If the episperm adhere to the endocarp, the direction of the seed cannot be determined with- out first discovering the point of attachment. To ascertain this, we may proceed either to a See tab. 3. fig. 9. b See tab. 3- fig. 11. 23 examine the two extremities of the seed, (of which the base will be indicated by a more marked vas- cular adherence, and by the origin of the peris- permic vessels, whose summit is denoted by the chalaza,) or to determine the position of the ovulum, which is much better. The point of annexion of the seed, and its di- rection with respect to the pericarp, character- ize essentially neighbouring species, indicate the affinity of certain genera, and are often common to the whole of a natural order. Erection of the seed is general in CoMpost- TEÆ, or SYNANTHEREÆ, &c; it places OPER- CULARIÆ between RUBIACE#& and DIPSACEZ; it separates Hippophae and Eleagnus from THE- SIACEÆ; it limits the number of ALISMACEÆ, distinguishes JONCAGINEÆ from PoTAMOPHI- LÆ, &c, Its ascending direction separates POMACEE from other ROSACEZ. Its suspension allies JASMINEE to APOCINEA, distinguishes GUAIACANZ from SAPOTÆ, : brings Callitriche near EUPHORBIACE#, groups some RosACEÆ, and contributes to separate the CuPULIFERZ from the true AMENTACEÆ. Its inversion brings together Zannichellia and Potamogeton, Ruppia and Zostera, and sepa- rates these four genera from ALISMACE& ; it 24 would bring Globularia near DiPSACEZÆ, if the structure of the ovarium did not prevent it. VISCOIDE#, (containing Chloranthus, Viscum, Loranthus, Codonium and Aucuba), are by it formed into a section of CAPRIFOLIACEÆ, and it seems to indicate some analogy between Adoxa and these last. It fixes HYGRoOBIÆ, (Hip- puris, Proserpinaca, Haloragis, Myriophyllum) near the yet imperfect order of ONAGR#; and it powerfully contributes to the distinction of SAN- GUISORBE&,* Every perfect seed is composed of two princi- pal parts, which are the episperm,” and the kernel. The perfect state of a seed is essentially indi- cated by that of the embryo. The episperm is the only proper integument of the seed, the kernel of which it immediately and completely envelopes. Itis always simple and formed by a vascular parenchyma contained between two membranes; that is to say, the a To the peritropal direction of the seed, M. Richard has not here adverted. It exists in Plantago, and anear approach to it serves to distinguish Crategus from Pyrus and Mespilus. Indeed attention to the insertion of the seed in these three genera will separate them into very natural groups. Pyrus will contain all the species whose fruit isa pome, inciading most, if not all, the American Mespili. Mespilus will, I believe, be confined to the eatable species, if it be dis- tinguished by the ascending position of its seeds and the bony puta- men of its fruit. Crategus will be limited to the species with angu- lar leaves, and essentially characterized by its nearly peritropal seeds. b Testa Gaertner. 25 epidermis, which is hollowed or interrupted towards the hilum, and the inner parietal mem- brane, which is perfectly continuous. This last is often separable, either artificially or spontaneous- ly; and then some botanists have regarded the episperm as double. But this separation of a single integument into two, is ascertained by the rupture of their vessels, or by the nakedness of the parenchyma which united them. Most frequently the main vessels of the epis- perm take a direction towards one point, where they unite and form with the parenchyma an areola or tubercle usually opaque and differently coloured from the surface near it. It rarely hap- pens that one or the other chiefly originates from the expansion of the superior extremity of a sin- gle trunk or series of vessels. This areola or tu- bercle the learned Geertner named Chalaza, and it indicates the true or natural summit of the seed, * The episperm is for the most part simply ap- plied on the kernel, from which it is easily sepa- rable. But it also becomes adherent, and often with so much tenacity that it can only be remoy- ed by grating. This adherence may take place . whether there be any endosperm or not; whe- ther the embryo be monocotyledonous or 4 See (ab. 3, fig. 14, a 26 di-polycotyledonous ; sometimes it only takes place at the areola. The episperm is always unilocular; it is a mistake to admit the existence of many celled seeds. Of the Kernel.—The kernel (Nucleus) is the whole of that usually white substance, which fills the episperm, and consequently determines the size and form of its cavity. It has no vas- cular connexion with it by any point of its surface. If the kernel of a perfect seed be so entirely continuous, that no part can be detached from it without fracture or rupture of the parenchyma, it is formed by a single body which is the embryo.* If it be composed of two dissimilar bodies but contiguous, or enveloped the one by the other, without parenchymal continuity, one of these bo- dies is the Endosperm,” and the other the embryo. A third substance has been admitted in the body of certain seeds, under the name of Vitellus, but it seems tome to be only a part of one or other of the two preceding. Before treating particularly of these three parts, [ must premise, that the kernel of a ripe a See tab. 2, fig, 6. a. and 7. b Albumen of Gærtner. See tab. 2. 13 a, Albumen, 6, Embryo. 27 seed may be either incomplete by the absence of its embryo, or monstrous by a plurality of em- bryos. But a little practice in the dissection of seeds, and an exact knowledge of the distin- guishing characters of the endosperm and the embryo, will soon place the observor beyond any danger on this head. The seeds of some plants seem to be always imperfect; such for instance is the case with Monotropa Hypopithys. 1 have frequently analysed with the utmost care, seeds of it collected in various places and at different seasons, and have never been able to discover a true kernel. Is it possible that this plant can be a Peloria of Lathrea Squamaria ? The Endosperm (Albumen, Gert, Perisperm, Juss.) is that part of the kernel which forms at the side or around the embryo, a body of a simi- lar texture throughout, uniformly continuous, without sap-vessels, and having no parenchymal continuity with it. It is almost always white or nearly so; some- times yellowish, very rarely green, as in Viscum. Its white colour, its texture, size, or tendency to separate easily from the episperm, form the most common distinction between the two; but frequently its extreme tenuity and firm adhe- sion, make this difference less evident, because then the endosperm forms a scale so delicate 28 and closely glued to the episperm, that it may be mistaken for the internal lining of the latter. If its colour and texture, which are usually suffi- cient for the practised botanist, do not establish with precision its presence where it is expected to exist, we must recur to other means in order to decide. Natural or characteristic affinity, the beacon to the philosophical botanist, ought immediately to solve the difficulty. Thus, if we know from de- scription, or, which is better, from actual obser- vation, that a plant of the same natural order, or of the same genus as that of which we are examining a seed, has an embryo provided with endosperm, we may rationally expect it should exist in the plant under consideration also. This probability tends to excite our sagacity, while it removes our difficulties, and it may be the means of discovering this crgan in some cases, where it would other- wise have escaped observation. Thus if we ana- lyze by itself the seed of Daphne Mezereum, we shall not distinguish the endosperm: the excessive tenuity of which, and especially its unusual lateral interruption, render it at first imperceptible; but but if it be compared with its allies, we shall soon perceive that the endosperm evidently exists, and that it varies in thickness. This double discovery excites us not only to pursue our examination, but also to search for some species of the same 29 genus, where it may be more evident. Accord- ingly by submitting to analysis the seed of Daphne Laureola an endosperm will be easily discovered, in the form of two very thick fleshy scales, ap- plied to the back of the cotyledons, attenuated and confluent at their two extremities. Transferring our examination to the seed of Daphne Mezereum, we readily now perceive the same envelope existing about its embryo; but so delicate that without such a comparison, it might have been confounded with the episperm. But when this advantageous method of compa- rative analysis cannot be applied to a seed in which the presence or absence of the endosperm is doubtful, we are reduced to an abstract exami- nation, the result of which is so important, that a frank expression of doubt, is preferable to a decision without evidence, It will readily be perceived that all the difficulty of this examina- tion consists in fixing the internal limits of the episperm. Now this limit may be known, first, by the sudden termination of the parenchyma, and of the vessels which are peculiar to it; se- condly, by the interior structure of the areola, or chalaza; thirdly, by an examination of the embryoniferous cavity. 1. If the membrane immediately applied all over the embryo appear veined, or if if be so 30 delicate that it suddenly defines the parenchyma of the episperm, without a possibility of cutting or tearing off a portion, without altering the parenchyma or its vessels—if the parenchyma- tous tissue without any remarkable difference be applied on the embryo, at the same time firmly adhering to it—the limit sought for is in these cases at the very surface of the embryo, and consequently there is no endosperm. 2. This organ is equally absent when the par- ticular skin of the chalaza, or even its paren- chyma touches the embryo, and above all, when the latter immediately receives from it a modifi- cation either in its form or colour, 3. The most difficult part of the question, (the solution of which is more easily obtained by long practice, than certainly given by precept) is to fix the true limits of the episperm, when the embryoniferous cavity is lined or formed by a white or whitish scale, more or less fleshy, and not adherent to the embryo. If this scale be so united to the parenchyma of the episperm, that the vessels of the latter penetrate at least a portion of its exterior face in such a way, that the colours and the substance are not then sudden- ly cut off—if by a clean section the gradual change from the same parenchyma can be dis- tinctly recognised—if the internal face shew 31 vessels passing especially towards the hilum or the chalaza, the scale may be considered to be- long to the episperm. Ifon the contrary, this scale be totally distinct, by its colour and entirely homogeneous substance, and seem to be formed as it were by incrustation—if its superficies do not appear to be wrinkled—in one word, if it have not the above mentioned characters of the internal lining of the episperm, we must in spite of its adherence to the latter, and notwithstand- ing its tenuity, consider it a true endosperm, The presence and absence of endosperm fur- nishes two generic, and frequently ordinal charac- ters, which are mutually repulsive. Its absence is remarkable in Nelumbium, Crescentia, The- vetia, &c. Endosperm may exist in the seed, although its embryo be abortive, or even if the latter be absent altogether. It is always simple even when there is more than one embryo.* If it is pierced or interrupted, the hele or interruption never an- swers to the extremity of the cotyledon of the embryo which it envelopes. Its substance immediately about the embryo not unfrequently assumes a different colour and density, especially in Monocotyledones ; some- times this part even separates from the rest, a See tab. 3. fig. 16. 32 The embryoniferous cavity is always single; if there be more than one embryo, it either re- mains simple, as in Allium fragrans, or else it divides itself into as many ears, always confluent, as there are embryos, as in Viscum album. * This cavity is usually formed on the mass of the embryo ; very rarely it follows the plaits of it, as in CONVOLVULACEÆ.? The Embryo is that body which forms entirely, or in part, the kernel of a perfect seed, and con- stitutes the already formed rudiments of a new plant.° If the embryo forms by itself the entire kernel, and is immediately covered over by the episperm, it is called epispermic ;% it is termed endospermic® when endosperm is present.‘ An endospermic embryo is internal when it is a See tab. 3. fig. 16. b See tab. 2. fig. 18. c See tab. 3. fig. 15. a. 16.6. Ke. d Exalbuminous. Geert. e Albuminous. Gært.—but these terms are applied to the seed by Gertner, not tothe embryo. Thus an exalbuminous seed is the same as perispermic embryo—Albuminous seed as endospermie embryo. f Tt is a very curious remark that in all exorhizal exalbuminous seeds, the gemmula is pretty evident; whilst most of those which are albuminous appear to be without it. See Richard in Ann. du Mus 17. 447, 33 enveloped by the endosperm ;* external, when it is applied to the latter outwardly ;® the first is much more common than the second, Its situation with regard to the endosperm is modified by its form, and furnishes, by its con- stancy and diversity, very good characters for ge- nera, and even for orders. - x Its form is independent of that of the endos- perm. It is always smooth. Plurality of embryos indicates monstrosity. Externally we distinguish two extremities ; the radicular, and the cotyledonar. The radicular extremity of the internal em- bryo sometimes immediately touches the epi- sperm ;° but the cotyledonar never appears te offer such a contact. Sometimes the radicular end adheres firmly to the endosperm, as may be observed in many Mo- nocotyledonous plants; very rarely it seems to contract a sort of parenchymatous adherence with it, as in CYCADE#, and CONIFERÆ; Casuarina which does not possess this last character, belongs to the family of MyRICE&. a See tab, 3. fig. 16, &c. b See tab. 5. fig. 2, and 3, © See tab, 3. fig. 15, and 16, &c. D 34 Sometimes the radicular extremity penetrates immediately into the substance itself of the epi- sperm, as in Hippocastanum vulgare,* and Sa- pindus ; but this is very rare. The epispermic embryo may be either homo- idous, i. e. having the same form as the seed ; or heteroidous, when the shape is dissimilar. It is by means of the two extremities of the embryo, that we are able to determine its par- ticular and relative direction, The particular direction of the embryo, is that of its mass considered abstractly, This, combin- ed with its form, generally presents a beautiful character for genera, and often even for natural orders ; but then we must overlook such trifling modifications as may result from those of the seed itself. The relative direction of the em- bryo is its particular direction compared with that of the pericarp or the seed. The first comparison establishes the relation of direction between the extremity of the radicle and one of the points of the seminiferous cavity. The second indicates the direction, or the po- sition of this extremity with respect to the centre of the base of the seed. a See tab. 3. fig. 17. 35 The direction of the embryo with respect to the pericarp, is called pericarpic ; that with res- pect to the seed we shall term spermic.* There are some other epithets which are ap- plied to the embryo with respect to its direction. It is homotropous, when it has the same direc- tion as the seed—orthotropous, when like the last, but straight: it is antitropous, when its direction is contrary to that of the seed—hete- rotropous, when it does not follow the direction of the seed—amphitropous, when its two ends are turned towards the hilum. The homotropous embryo, or that which has the end of its radicle answering to the hilum, is common; some Monocotyledcnes, certain So- LANEÆ, RUBIACEzx, &c. offer examples of it. The orthotropous embryo, which is straight, and has exactly the same direction as the seed, is very usual, whether it be upright, as in most Mo- nocotyledones, some RUBIACEX, COMPOSIT&, &c. or with the seed inverted, as in TYPHINEZ, DiPSACEÆ, UMBELLIFERÆ, &c. Examples of an antitropous embryo are a Thus in Rosa, the embryo, as regards its spermic direction, is homotropous ; but is antitropous, if its pericarpic direction be consi- dered. See tab. 3. fig. 12. 2 36 somewhat rare ; but it furnishes excellent generic, and sometimes ordinal characters. T shall cite a few examples of it. 1, In the ascending seed— SAURUREZ, Hy- DROCHARIDEE ; true MELAMPYRACEZ ; Acan- thus; Nepenthes, whose embryo is interior, and cleft a little beyond its middle into two cotyle- dons ; &c, 2. In the erect seed—some THYMELEZ, MYRICEz, &c. 3. In the inverted or suspended seed—Po- TAMOPHILÆ or FLUVIALES; Ceratophyllum, Platanus, ERIOCAULES, &c. 4. In the peritropal seed—EPHEMEREZ or COMMELINEZ. The heterotropous embryo, neither of whose extremities answers exactly either to the base or the summit of the seed, is not common. [It allies Samolus tothe ANAGALLIDEM, among which it is nearly general; it isolates Anguillaria; serves as a good distinction between GRAMINEX and CYPERACEZÆ, whose embryo is always orthotro- pous, &c. 37 The amphitropous embryo which is so recurved that its two ends almost equally approach the hi- lum, forms a clear character for ALISMACEÆ; is general in ATRIPLICES, and other neighbour- ing orders; CARYOPHYLLACEÆ ; CRUCIFERE ; some species of Allium; Cneorum; Ternst- romia ; Cannabis; Hippocastanum, &e. It assembles some genera around Cissampelos, of which Wal-tiedde of Gærtner is a species, The pericarpic direction of the embryo, fre- quently offers remarkable differences and oppo- sitions in the same natural order, and even in the same genus, but this last is very rare, It is sometimes impossible, and frequently difficult, to establish it justly; especially when the seeds are vaguely directed. In many genera it is not easy to indicate it without knowing the precise point and manner of annexion of the seed. As the direciion of the seed ought always to be ‘considered with respect to the pericarp, so that of the embryo must always be compared with the seed. Two examples will suffice to demonstrate the utility of this principle. If we compare the genera Bucida, (singular on account of its ovarium with three ovula) Nyssa, 30 Thesium, &c. with some THYMELEZ, we shall find that the pericarpic direction of the embryo is the same in each; that is to say, that the embryo is equally reversed. Nevertheless, the embryo of the first is orthotropous, of the second, antitropous. Each of the three cells in the ovarium of the genus Hippocastanum contains two ovula; the one erect, the other inverted. Each of the four cells in Halesia and other STYRACEÆ, contains ovula, differing by pairs in asimilar way, When the two ovula of the first, and one of each pair of the second, have been fecundated, there remain in the same cell two seeds, the pericarpic direc- tion of whose embryo is opposite ; but the sper- mic direction remains the same. This also obtains in Arum Dracunculus, whese ovula and seeds are both upright and inverted in the same fruit, Now let us proceed to consider the structure of the embryo. The parts which characterize the embryo, are Ist, the Radicle ; 2nd, the Cotyledon, which is either simple or divided; 3rd. the Cauliculus ; Ath. the Gemmula. 1. Radicle. This forms one of the extremities 39 of the embryo; it is always simple and perfectly undivided through the centre of its base.* 2. Cotyledon.—When it is simple, it is com- pletely closed ; that is to say, it has neither inci- sion nor cleft on any point of its surface.? When there are many cotyledons, they spring immediately from the same point, and are exactly opposite or verticillate.° 3. The Cauliculus runs on the one hand, into the radicle, of which it is only an extension, and on the other, terminates at the base of the coty- ledonary cavity, or at the division which distin- guishes the bases of the cotyledons.‘ 5. The Gemmula® is the little simple or compound body which either springs from the bottom of the cotyledonary cavity which com- pletely encloses it, or between the bases of the cotyledons by which it is concealed or sur- rounded. The first observers called it Plumula, because in the seeds submitted to their exami- nation, it seemed to resemble a little feather.‘ The exterior surface of the radicle and coty- ledon, united by the cauliculus, constitutes that of the embryo, a See tab. 3. fig. 15. b, &e. b See tab. 3. fig. 8. c See tab. 2. fig. 7. a. d See tab, 2. fig. 6. 7. 5. e Plumula Gærtner. f See tab. 5. fig. 2. a, tab. 3. fig. 17. a. 40 The embryo should always be considered in its state of inaction. Germination ought never to be considered with respect to the embryo, except as the means of better understanding some particular part, The absence and the presence of the embryo, P y form the base of my two first great divisions of plants—ExXEMBRYONATÆ and EMBRYONATEÆ. Or EXEMBRYONAT#&.—Plants of this division are characterized by the absence of an embryo in the corpuscles with which they are furnished, instead of seeds, These corpuscles have no hilum, and are not covered with a parenchyma- tous integument. They have been called ACOTYLEDONES ; but this word seems improper, because it does not always exactly indicate the distinguishing charac- ter which has been attributed to them. Be- sides, it ceases to form an important feature in my new division. They are also known under the Linnean name of CRYPTOGAMOUS plants. But I am persuaded that Nature has not furnished them at all with sexual organs, which would be quite useless to them. A prejudice of the necessity of sexes in all vege- AY tables, has hitherto contributed to conceal this truth from the most acute observers, who, however, are the more excusable, because, un- like their parasites, they have paid to science a tribute of facts collected by actual observation. That you may be the more able to recognise these errors, I shall, before I treat particularly of EXEMBRYONATÆ, submit to your consider- ation, certain remarks which will be of material assistance in your search after the truth. Since we know that the propagation of some animals can take place without the existence of sexes, what reason can there be why vegetables should not also be capable of reproduction by corpuscles, which may have the property of vegetating without fecundation ? The reproductive corpuscles, which that excel- lent observer Hedwig, has called Sporule, sometimes differ so materially from each other in neighbouring species, and even in individuals of the same species, either in form and thickness, or in their receptacle, that they point out by that very circumstance, how distinct their nature is from that of seeds. ‘The uniformity of the plan which nature pur- sues in their formation, from the arborescent 42 ferns to the microscopic fungi, is not only admi- rable, but yet more strongly proves their identity throughout the whole series, and the impossi- bility of their sexual fecundation. Since the formation of an embryo makes it necessary that fecundation should actually take place, the organs destined for that purpose should be found in those plants only, which are reproduced by seeds. Sporules differ from seeds, not only in the manner in which they are formed,* but above a The rudiment of a sporule is one of the cellules, or a cellular portion of the substance of its receptacle. This cellule dilates and is filled by degrees with a peculiar matter, whose adherence to it is constantly increasing. When this mattcr has acquired the nature and the volume necessary to the perfection of the sporule, the cel- lule detaches itself from its neighbours, or from its receptacle. The internal substance of the receptacle may be made up of cellules, im- mediately, and in every sense, united with each other; if they be all equally filled, the whole substance becomes converted into sporules, at maturity. Ifsome part only have received the sporular matter, the others remain coherent either together, or with the receptacle, with interruptions or spaces occasioned by the emission of those cellules which are become sporules. If the superficial matter of the receptacle be very delicate, it may either fail away piecemeal, or drop with the outer sporules. But when the cellular internal struc- ture of the receptacle is traversed by vessels distinct from the cellules themselves, these vessels which have been considered as a placenta, fall with the sporules, or else remain in the form of filaments, or of a kind of tissue. Richard in Ann. du Mus. 17, 444. The opinion of the absence of sexes in Cryptogamons plants, has received material support from some acute and valuable obser- vations on the germination of Mosses, communicated to the Lin- næan Society by Mr. Drummond, of the Cork Botanic Garden. It is to be hoped that this very curious paper will soon appear in the Transactions of that body. 43 all, in their want of embryo. A perfect sporule excited by germination, creates what it first pro- duces. The germination of a perfect seed, first unfolds the pre-existing parts of its embryo. The points of germination of the first are uncertain; the embryo of the second has always two which are determinate and opposed to each other.? But I must dismiss the consideration of these plants, since, as they have no embryo, they are in some measure foreign to the subject. Or EMBRYONATÆ. Embryonate plants are such as are provided with sexual organs, and are reproduced by anembryo. This embryo has received from the reciprocal and momentaneous action of the air, that principle of life which the sporule draws immediately, and during the whole time of its formation, from the vascular texture of its receptacle. F divide EMBRYONATE plants into two great series; ENDORHIZÆ and EXORHIZ&. The essential characters of Endorhizeé are, a The embryo of some ArotDEx, such as Calladium, has been ob- served by Mr. Brown to offer an apparent exception to this rule. “In these the nucleus of the seed is not properly a monocotyledonous embryo, but has an appearance and ceconomy more nearly resembling those of the tuber of a root; for instead of being distinguishable into a cotyledon, a plumula, and radicula, and of germinating in a particular manner, and from a single point, it is composed of a mass whose internal structure is uniform, and on the surface of which fre- quently more than one germinating point is visible.’ See Mr. Brown’s remarks in Linn. Trans, 12, 150. 44 that the radicle emits from its extremity dur- ing germination, a tubercle which before was interior, and which becomes the principal root of the young plant. It rarely happens that an enlarged body occupies the place of the radicle, and forces the internal tubercles to break through the sides of the cauliculus, In Exorhize the radicular extremity of the embryo itself becomes the root of the nascent plant. Hitherto botanists have founded the principal divisions of Vegetables on the number of their cotyledons; separating sexiferous plants into Monocotyledones and Dicotyledones, to which must be added with the immortal Gærtner, Polycotyledones. This numerical principle for main divisions, is seducing by its apparent sim- plicity; and if it could always be reconciled with the affinity of natural orders, its priority would give it a right to be preferred to any other. But it will be seen by the sequel that it not only does not possess this important quality, but that in its application it presents here and there some striking difficulties and uncertainties. The character I propose for the two series, appears to be immutably established by nature. a See tab. 5, fig. 1. a, and 3, 45 Lam warranted in considering it constant, by very numerous observations. It is independent, first, of the remarkable dissimilitude of the parts that are called radicles and cotyledons, Secondly, of the variation of their number. Thirdly, of the anomalies they present. It also admits the aid of aflinities derived from the differences in texture, of which botanists make more use than of the embryo,* to refer plants to their primary divisions, It has moreover a double advantage over these latter; it is the first cha- racter that is indicated at the commencement of germination, and may be the last examined, either immediately, or by the assistance of the sheath of the cotyledon, when the latter is itself obliterated by germination. It is evident by the two characters [ have drawn from the radicular extremity of the embryo, that what is called radicle in certain plants is essen- tially different from what bears that name in others. The difference in the cotyledons is necessarily inherent in that of the radicles.. What I have said of ENDORHIZ&, is sufficient a The characters of the vegetation of Dicotyledones and Monoco- tyledones, as proposed by M. Decandolle, are as follows : I. Dicotyledones or Exogene, Trunk conical, composed of bark and wood; the exterior part of the wood, younger and softer than the rest. IT. Monocolyledones or Endogene. Trunk cylindrical, homogene- ous, younger and softer in the centre. 46 to " that the admission of more radicles than one in an embryo, is erroneous. Variation in the number of cotyledons, in the same natural order, in neighbouring species, and even in the-same individuals, is notorious in CONIFER. Unity of cotyledon, accidental plurality, and here and there, their adhesion ina single mass, are anoma- lies which weaken and obscure the character of Dicotyledonous plants. Or ENDoRHIZ&. Endorhizæ are the true monocotyledenous plants of authors. Many Bo- tanographists have written on these plants with- out giving themselves the trouble to examine the embryo on which they founded their denomina- tion, Nevertheless, its structure might have offered them a differential character, less equivo- cal than such as may be obtained from the tex- ture of other parts, I cannot refrain from expressing my surprize, considering the number of years I have here publicly demonstrated the singular structure of the monocotyledonous embryo, that no one should, as far as I know, have robbed me of the priority of my discoveries on this head. Their publica- tion would have been useful to the science, and this itis which has already consoled me for more than one plagiarism and loss of anteriority, The same idea would have again diminished my re- 47 gret. But I know how much men are naturally attached to the principles which support their writings and their glory. It is chiefly therefore, on the attentive young men, whom I address, that I have founded the hope of one day seeing the fruit of the new observations I annually ex- pose to them, arrive at maturity. This hope in- duces me again to go over, with some additions, what concerns the embryo of ENDORHIZ&. The embryo of ENDORHIz&, is not divided by the two extremities of its radicle and cotyle- don, and it offers no lateral separation between them. To distinguish these extremities, is often therefore no easy task. Here the excellent work of Gærtner contains some mistakes, as in ARO- IDEZ, ŒYPHINEx, Zannichellia, Triglochin, &c, ; that illustrious author must have possessed a vast deal of sagacity not to fall into more errors, since he determined on the radicle and cotyledon without the aid of analysis, Nevertheless, with- out the latter, this denomination is almost always uncertain ; a truth of which the great carpologist seems to have been aware, since he has frequent- ly confined himself to indicating the absolute po- sition of the embryo. The distinction between the radicle and coty- ledon, is the more important, as it serves to determine the spermic direction of the embryo. 48 Without this distinction, we should be deprived not only of the excellent character which it fur- nishes, but also of the means of describing these two parts. Let us then examine generally, the internal structure of the embryo of ENDORHIZx, before we attempt to distinguish its extremities with greater certainty. The radicular extremity encloses or produces a tubercle which is internal, and which, during germination, pierces or bursts through the apex of the radicle and becomes elongated as the rudi- ment of a root. I call it primary radicle. This extremity is rarely terminated by a large radicular body, of which I shall presently have occasion to speak. In GRAMINEZ, where this body exists, a conical projection of the cauliculus resembles a radicle and sometimes contains se- veral radicular tubercles. As in Avena, Hor- deum,* Secale, Triticum, Coix, &c. Hitherto some celebrated botanists and those who have copied them, have regarded such tu- bercles as so many radicles, and have attributed to these genera a multiradicular embryo. But it is only necessary to dissect the radicular extremity or the base of the cauliculus to discover these a See tab. 5. fig. 1, 2 49 tubercles which are at first enclosed in it, and then the former no longer forms of itself the radicle, Now if the radicular extremity of the embryo of ENDORHIZ® be not itself the radicle, the cotyledonar extremity cannot be considered coty- ledon; this must also be dissected, and then we shall find that it sometimes encloses the rudi- ments of several leaves, as the other conceals the rudiments of many roots. I do not think it necessary to proceed further in order to convince you that the analytical mode of naming the parts of the embryo of ENDORHIZÆ cannot be erro- neous. Thus the knowledge of one extremity will determine the other ; but it will soon be perceived that the cotyledonar is the better index of the two, The cotyledonar extremity, or the cotyledon, is usually almost solid, containing only a little cavity at the base, which closely shuts up the gemmule, Sometimes this cavity occupies the middle, or the axis; sometimes it is nearer one side than the other, and then it usually inclines towards that side which is next it. It is by a longitudinal division of the embryo in a state of repose, or just beginning to germinate, that this gemmuliferous cavity is most easily dis- covered ; the gemmule is then fixed by its base E 90 which points towards the radicle ; otherwise it is disengaged. This free extremity it is, that it is first necessary to discover, since its direction usually indicates that of the embryo with respect to the seed, and points out the cotyledon, and con- sequently the radicle. The embryo of ENDORHIZZ, is very rarely epispermic, or without endosperm: [I have never yet seen it so, except in Nelumbium,* HYDRo- CHARIDE®, ALISMACEÆ, POTAMOPHIL#, JON- CAGINEÆ, BUTOMES, &c. The embryo of ENDoRHIZÆ then, is usually endospermic, and almost always internal; I am not aware of its being external, except in SAU- RURES,* PIPERACEZÆ, ERIOCAULES, GRAMI- NEÆ, HYDROPELTIDER, and NYMPHÆACEZÆ. In Musa, ZINGIBERACE®, EPHEMERE#X or CoMMELINES,’ some CYPERACES, (Scleria) &c. the radicle is enclosed in a hollow projec- tion of the episperm, and enveloped by a very delicate membranous elongation of the endosperm. When in a dry state, this extension is difficult to perceive ; care must therefore be taken not to fall into a mistake, by considering the hole of the endosperm which contains the radicle to be closed by the episperm alone. a See tab. 4. fig. 1. b See tab. 4. fig. 8. * Cyamus, Smith, Exot. Bot. V.i. p. 59. 51 When one of the two extremities of the endo- spermic embryo is manifestly nearer the episperm than the other, itis thatextremity which contains the radicle. If this law, to which I as yet know no exception, preserve its general application, it will often supply the necessity of dissection.* The embryo is generally straight; it may be variously curved, but is never plaited. Its two extremities are usually of the same shape. Therefore names cannot be deduced either from the exterior dissimilarity or from the con- formity of different embryos. Cabomba,” EPHE- MERES,° &c, have a fungilliform embryo, al- most like that of Musa, ZINGIBERACEZÆ, &c; in the first the radicular extremity is thickest, but the contrary is the case with the second. The cotyledon is often straighter than the radicle ; in Dioscorea it is much dilated and extremely at- ‘ tenuated. Or THE VITELLUS. The embryo of some ENpDoRUIZ# has so remarkably different a struc- ture from that which I have just explained, that the great carpologist has attributed to them one a This idea is completely confirmed, except in Gramine®, by the subsequent observations of the learned author. See Annales du Mu- seum, 17. 447. b See tab. 4. fig. 9. c See tab. 4. fig. 8. d See tab. 4. fig. 10, 12. © See tab. 4. fig. >. 52 part more than the others. In the examination J am about to make of the pretended vitellus of Gærtner, I shall proceed for the sake of clearness from the most simple vitelliferous embryo to the most compound. First, however, I shall remove from this im- portant article ZINGIBERACEZ, in which the vitellus is nothing more than a central indurated portion of the endosperm.® Zamia must also be removed, since it belongs to EXORHIZ x. The vitelliferous embryo is either epispermic, asin Ruppia, Hydrocharis, Zostera, Nelum- bium, or endospermic, asin GRAMINEZ, 1. That of Ruppia‘ is formed by a great white, amygdaloid, solid body, the upper extremity of which appears obliquely cut off and rather concave, producing a filiform, cylindrical corpuscle, which inclines suddenly towards the point of attachment of the seed, The substance of these two bodies is so continuous that the lesser is manifestly only an elongation of the larger. Divide the cylinder longitudinally ; you will find on the inside a little above its origin, near the curvature and on the side opposite its inclination, a very minute ca- vity, This contains a conical compressed body 4 In tab. 4. fig. 3, and 4. a is the Vitellus, b See tab, 4. fig. 12, and 13, c See tab. 4. fig. 14, and 15. 53 whose free extremity is directed towards that of the cylinder. Referring to what I have said above, it will easily be seen that this corpuscle is the gemmule ; that the cylinder which encloses it is the cotyle- don, and that the great body, named vitellus by Gærtner, is reaily the radicle enormously dis- tended. 2. If the seed of Hydrocharis* be stripped of its episperm, and of its outer integument, which is formed of numerous cylindrical vesicles united at their base, it will present an oval kernel which appears entirely solid. But casting the eye over it attentively, we can just perceive on one of its sides near the middle of its length, a very little hole which penetrates across the kernel almost to its centre. From the bottom of this hole springs an oblong body which fills it, and whose extremity so completely stops up the orifice, that the super- ficies of the surface does not appear to be inter- rupted. This body is the cotyledon enclosed in the radicle, of which, as in the former genus, almost all the kernel is composed. From these two examples of an unusually large 4 See tab, 4, fig. 16, 17, & 18. 94 undivided radicle, I pass on to the plant in which it is, as it were, two valved. 3. The kernel of Zostera* is an oblong oval, and presents at its upper end a cavity in which is received a swelling of the base of the episperm. Throughout the whole length of the posterior sur- face, it is cleft almost to the axis. From the middle of the centre of this cleft, and nearly through the centre of the entire mass, springs a filiform body which forms a bend in its descent to the lower end of the kernel, and then again takes an opposite direction towards the contrary ex- tremity, continuing to preserve its proximity to the cleft, through which it may in part be seen. Dissect this body, and you will find at the very bend an internal flattened cavity, nearest the out- side, with the curvature of which it preserves its parallelism, This cavity encloses a gemmule much shorter than itself, (which is unusual,) broadly ligulate, rounded, obtuse, with its fixed extremity looking towards that of the corpuscle. The de- scription I have given of the two first, will make it sufficiently clear to you that the almond-like divided body of the present, which has been called vitellus, is the radicle ; you will also recog- nize the cauliculus in the part which descends from that body to the gemmuliferous cavity, and the cotyledon in the rest. 4 See tub. 4 fig. 19, 20. 99 4. The genus Nelumbium* is not less remark- able for the structure of the embryo, till now im- - perfectly known, than for the other characters which are peculiar to it. (The identity of its ra- dicle with the vitellus of Geertner was first dis- covered by Correa de Serra.*) The kernel of Nelumbium is either a short oval, or a sphere, terminated at the lower end by an areola, which seems mammillary, and is of an hard amygdaline white substance, Itis nearly divided the long way into two equal lobes, slightly united at their upper extremity into acommon base, which is also that of the in- verted kernel. Between these two lobes, whose interior face is alittle concave in the middle, is contained a body which appears suspended from the centre of their common base, and almost as long as them- selves, but much narrower. This body is com- pletely enveloped in a sort of membranous bag, which like it, originates from the common base of the lobes, This covering is extremely delicate, of a whitish colour, becoming pulpy by macera- tion. Itis so brittle when dry, that it never can be found perfectly entire in old seeds. The body it encloses is green, pierced all over by little a See tab. 5. fig. 5, and 6. * See Smith on this subject, Tr. of Linn. Soc. V. ix. p. 204. 56 superficial pores ; its lower end is a little cylin- drical stem ; the upper is longer and thicker, and seems to be divided in two, being formed of two very unequal rudiments of leaves ; the petiole of the largest, bends down in sucha way that the summit of the disk of its leaf is brought up to the point of bifurcation; the other is seldom erect, but usually bends down so as to apply its disk to its base in the inside. The disk of each leaf is fixed to its petiole by nearly the middle of its back ; it is spindle-shaped, and its two edges are rolled inwards. The base of the larger petiole on the inside is naked ; but the lesser has a small oval bud, formed by the sheath split on one side, and filed with the very minute rudiment of a leaf which in its turn is gemmiferous also. It now remains to determine on the names of the different parts we have analysed. This kernel is an inverted embryo; the radicle instead of being simply cleft as in Zostera, is deeply divided into two parts. The cotyledon is the sacciform covering of the green body which is the gemmule. 5. The species of Nymphea with yellow flowers ought to constitute a genus, which for the present I would name Nymphozanthus.* It is chiefly a See tab. 5. fig. 7, and 8. Nuphar of Salisbury, who effected this division two years before the publication of the Analyse, See Annals of Betany.— And Sith Prodr. Fl. Grec. V.i. 361, 97 distinguished by the persistence of the calyx: by the form of what are called petals: hypogynous insertion of stamina: &c. The kernel of the seed of Nymphozanthus vul- garis, is oblong-oval, and almost entirely formed of a white endosperm, which is at first fleshy, afterwards farinaceous and friable by desiccation. At the narrowest end of this endosperm is situ- ated a little spheroid body which is turbinate in a slight degree, whitish, and partly enclosed by the former, but covered otherwise by the episperm. This spherical substance is the embryo. It iscom- posed, first, of a sort of tunic completely closed and undivided, thin, fleshy and a little coriace- ous ; secondly, of a corpuscle, which fills the cavity and assumes the form of the latter, attach- ed only by its outer end or that which is opposite to the endosperm. The tunic is the cotyledon; the end by which it unites with the corpuscle is the radicle; the corpuscle itselfis the gemmule. This gemmule is deeply divided into two thick, fleshy pieces, which by their approximaticn, conceal a third, which is pale green, oval, remarkably com- pressed, and slightly divided on one of its edges. This description shews that the embryo of NYMPHEACES, brings them near HYDROPEL.- TIDEÆ, SAURURE®, and PIPERACES. 58 6. The genus Nymphæa, in which the insertion of the petals and stamina is pleurogynous, does not differ from the preceding as far as regards its kernel ; except that the embryoniferous spheroid is so remarkably depressed that it is not so long as broad. At present I know of only one exam- ple of this mode of insertion amongst EXORHI- ZH. It exists in Parnassia. 7. The botanical analysis of the seed of GRA- MINE more particularly requires your attention, both because it is in itself very difficult, and be- cause the descriptions you will find in the best authors are not only incomplete, but in part erro- neous. ‘The last assertion surprizes you: what! you will say, the seed of corn, as common as it is interesting by its utility, is that not yet under- stood by botanists?’ Remember that the progress of science is necessarily progressive, and instead of criticizing the writings of others, let us add our own observations, The grain of GRAMINEZ is covered with two integuments which are very delicate, and almostal- ways united so inseparably that they appear to form but one. A brownish spot at the base, or a lon- gitudinal taway line, which I call spilum, indi- cates the hilum of the seed or the true point where it is connected with the outer integument which is the pericarp. At the base of the grain 59 on the outside is a sort of areola which indicates the scite of the embryo, and to which I give the name of areola of the embryo. The embryo* is applied obliquely and laterally on the base of an endosperm, which is farinaceous, and much larger than the former; so that the whole of its front surface and lower end are im- mediately covered by the seminal integuments. This embryo is composed, like those which are called vitelliferous, of two distinct bodies; one, posterior and larger; the other anterior, shorter, and narrower, The first I call hypoblastus ; it is a sort of fleshy disk, flattish in front, more or Jess convex or gibbous behind; its circumscrip- tion, which forms that of the embryo, varies in figure from orbicular to subulate. The second, named blastus, is a cylindrical body, lying longi- nally on the former, to which it is attached as it were by the middle of its length, so that its two extremities appear disengaged. Sometimes this cylinder seems simply applied to the posterior body; most generally it is retained by the two more or less projecting edges of a slight furrow, grooved out of this body; it seldom happens that the two edges of the furrow dilate and converge, so as to touch each other and entirely enclose the cylinder, a See tab, 5. fig. 1, and 2. 60 In certain genera, as Avena, Triticum, &c. a sort of appendage, termed epiblastus, is applied on the front surface of the cylinder, with the lower end of which it becomes united ; it seldom hap- pens that it covers the cylinder entirely, its edges coalescing with the posterior body, from which it is then scarcely to be distinguished, This struc- ture may be observed in the embryo of Oryza,* and of those to which it is allied. In the admirable and immortal work of Natural Orders, a precious mine of knowledge decried by certain writers more to the profit of themselves a With the greatest deference to the opinion of the learned and excel- lent author, it is necessary to observe, that my view of the structure of Oryza differs very materially from that which he has exposed both in the present work and in his more recent and extended observations in Annales du Museum. M. Richard describes and figures the ex- terior surface of the embryo as perfectly continuous ; an unusual struc- ture in the order, which he explains, by saying, that the epiblastus coalesces with the margin of the little cavity in which the blastus is lodged. The origin of the mistake seems to be this ; if old seed- vessels of Rice be macerated for a long time, or fresh ones for a short time, the testa and the pericarp come off together without apparent disunion, and the real surface of the embryo is exposed ; but if Rice in a fresh state be submitted to the action of hot water for two or three hours, the pericarp readily detaches from the testa; the latter by this operation becomes unusually fleshy, and adheres to the surface of the embryo, from which it is not readily separated, and for which it appears that M. Richard has actually mistaken it. (See tab. 6. fig. 10, and 11.) Ihave no doubt that such must have been the cause of an error which is the more necessary to be pointed out, as it has oc- curred to a botanist in the well known accuracy of whose observations the greatest confidence may be placed. The surface of the embryo of the genus before us, instead of being continuous, presents about its middle a small squamiform body (part ofthe epiblastus, Rich.) in some degree concealed by the superincum- bent attenuated margins of the hollow in which the plumula (blastus Rich.) lies. Mirbel has taken the same view of the structure of Oryza as M. Richard, and probably from the same cause. 61 than of science, the posterior body is called the cotyledon, Gertner named it vitellus scutelli- formis or simply scutellum, and he has taken the cylindrical part for the whole of the embryo. Now let us examine the singular structure of the embryo. The pretended vitellus is the body of the radicle; the point by which the cylinder is attached to this, is the base of the cauliculus ; the lower extremity of this same cylinder is a la- feral protuberance of the cauliculus, enclosing one or more radiceilar tubercles ; its upper extre- mity is an oblique extension of the cauliculus, and is composed of several conical scales con- tained one within the other; that which is most interior is thicker than the rest and undivided ; and is the cotyledon. I have thus acquainted you with certain facts relative to embryos which have been considered vitelliferous. But facts are only the materials of science. To give them a suitable form and to com- bine them by analogy is to prepare them for building ; by uniting them we raise the edifice. The solid or philosophical elevation of a science is only effected then by arranging facts prepared in a manner suitable to the end proposed. We have already prepared them ; it now remains to unite them, since it is the only way to contri- bute to the real advancement of Botany. 62 Although the comparative name vitellus is not here justly applied, we must nevertheless admit, that its immortal author is not much to be blamed for having introduced it. By it he has not only given a proof of his sagacity; but he has done a service to the science by pointing out to botanists an extraordinary structure of the embryo of EN- DORHIZÆ. I shall proceed to examine the latter with regard to the size of the radicle. Let us recollect that it is always from nature herself that we should borrow the light which is necessary to guide us in discovering the ana- logy of her productions under the various masks with which she has disguised them. We shall then find that she has prepared the eye of the ob- server for this excessive enlargement of the radi- cle, by the gradations of different endorhizal embryos. These gradations are very evident in certain PALMÆ, SAURUREÆ, EPHEMERERS, Cabomba, &c. Even the formation of some Ex- ORHIZX will throw light on this point; since the genera Lecythis, Bertholletia, Pekea,* have an embryo whose enormous radicle constitutes, as in Ruppia, almost all the kernel of their seed. A tendency to similar enlargement exists in the ge- nera Zannichellia,” Potamogeton, and Naias. The thickness of their radicle is not much greater, a See tab. 6. fig. 4. b See tab. G. fig. 5, and 6. 63 except at the end, than that of the cotyledon, but the situation of the gemniule towards the middle of its length, or near the upper end of the embryo, gives the radicle a length unusual in ENDORHIZÆ which makes up for the thickness, Having sketched the chain which assimilates the embryo of Ruppia, to other ENDORHIZx, let us compare together this genus, Hydrocharis, and Zostera. Although the cylindrical corpuscle which springs from the body of the radicle be in part formed by the cauliculus, yet for the sake of brevity, I shall call it cotyledon. The cotyledon of Ruppia is seated in a little trough at the top of the radicle; a lateral hole receives that of Hydrocharis; a longitudinal cleft contains between its approximated edges that of Zostera. The chief difference between the embryos of these two last genera is the existence of a lateral hollow, instead of a longitudinal cleft. The concealment of the cotyledon in the radicle may be considered then to be gradual. It (the cotyledon,) is nearly all visible in Ruppia; the end of it only is seen in Hydrocharis ; a part of it is seen through the inferior hiatus of the cleft in Zostera. Now let us pass to the embryos whose cotyledon is perfectly concealed in the radicle. In considering abstractly the nymphoidal cha- 64 racters of Nelumbium, taking its pistilliferous re- ceptacle for a sort of alveolate spadix, and comparing its embryo with that of Zostera, are we not tempted to regard it as almost interme- diate between this genus and Nymphea? Some genus, hereafter to be discovered, may one day unite this approximation, which though sudden, does not appear to me to be far from the truth. The central point of the face of the radicle of an embryo, is at the lower extremity of the elon- gated axis of its cauliculus. This point in Zostera is that of the exterior face of the body of the radicle which answers to the origin of the cauliculus. Placing the body of the radicle on this point, its cleft becomes apicular, and it then resembles that of Nelumbium, which besides its form, differs only in having its separation deeper. Nevertheless this genus offers two remarkable peculiarities in its cotyledon and gemmule. The first, whose extreme tenuity and above all its fra- gility has caused it to be misunderstood, admits of no exact comparison with any other that I am acquainted with; that of GRAMINEZ is nearest perhaps. The second, which resembles germina- tion within the cotyledon, still differs from all other ENporuizz by the inflexion of the rudiments of its leaves, When I was in Cayenne, and examined for the first time the kernel of Pekea butyrosa, I was 65 astonished at finding no interruption of its surface nor any cavity in its sections, whether longitudi- nal or transverse. I then submitted to examina- tion that of Pekea tuberculosa*, which Gærtner has well described under the name of Rhizobolus, The latter having its cauliculus as well as the two little terminal cotyledons lying in a superficial hollow, I made a slight corresponding incision in the other, and discovered a similar cauliculus, but entirely enclosed in the substance of the ra- dicle. The resemblance between the kernel of Pe- kea tuberculosa and Ruppia is striking ; and if we compare that of Pekea butyrosa with the embryo of GRAMINEA, we shall be less surprised at the complete inclusion of the radicular cavity in that of Rice. These two comparisons also confirm the denomination of radicle, which I have sub- stituted for that of vitellus. By giving the embryo of GRAMINEZ the po- sition I have pointed out for Zostera, that is to say, by placing it on the dorsal protuberance, or convexity of the body of the radicle which is really its base, we see that the cauliculus, which is extremely short, and the cotyledon suddenly take a transverse direction. This direction being nearly the same as in Zostera ought to surprise us less than the caulicular protuberance A See tab. 6, fig. 4. F 66 directed the contrary way. The latter, which ts peculiar to GRAMINE#, resembles so much the usual extremity of the radicle of the embryo of ENbDoRHIz#, that botanists have regarded them as the same, But this projection is in reality no- thing more than a lateral extension of the base of the cauliculus which contains from one to six ra- dicellar tubercles. Nature, who always assists those who examine her productions with zeal, herself furnishes the proof of this assertion. In- deed in certain GRAMINE®, the base of the cau- liculus offers on different points of its contour, many other gibbosities which each also enclose a little radicellar tubercle, not differing from the principal protuberance except in size. Often also these gibbosities do not shew themselves till germination has commenced. The cotyledon of GRAMINE™® being nearly as in CYPERACEÆ beginning to germinate, a hollow cone, encloses several rudiments of leaves rolled up in each other. But this convolution does not usually exist in the second, which are besides essentially distinguished by their embryo which is orthotropous, axile, seated nearly at the base, and with a simple radicle, I think I have sufficiently shewn you that the structure of embryos called vitelliferous, does not essentially differ from that of other ENDORHIZ2, 67 except by the great body I have called radicle. if this denomination be rejected we must also refuse to consider the other extremity of the embryo as a cotyledon, and then the embryo of EN DORHIZ& can no longer be compared with that of EXORHIZ&. To render more easy the description of Embryos with a swollen base(Hmbryones macropodi,) | think it right to indicate by a particular name each of the bodies which compose them, I call Blastus the cylinder, whose upper part forms the cotyledon.* IT give the name of Hypoblastus to the great body of the radicle, to which the former is attached. The name of Epiblastus is applied to the ante- rior appendix of the Blastus of GRAMINEZ ; and the term Radiculoda to the protuberance of the cauliculus which appears to constitute its lower end. OF THE GERMINATION OF ENDORHIZ&. Desiring to vender my lecture on ENDORHI- ZÆ as useful as possible, [ cannot terminate it withont something on their germination. Some- thing, 1 say, because until I come to treat in another place of germination in general I shall a See tab. 6. fig. 10, 11, where a is the Blastus, (Embryo Gert.); bis the Hypoblastus (Scutellum Gert.); c the Epiblastus; and d the Radiculoda. F 2 68 confine myself to mentioning the principal marks. which characterize the plants with which we have been occupied. We call germination that first spontaneous action, by which the vegetable body, isolated by nature from the individual which produced it, indicates its first degree of increase, and its tend- ency to become itself a plant. Perhaps it might also be called Plantulation, since the formation and developement of a little plant is the result, The embrycs of ENDORHIZ# usually undergo fewer changes during germination than those of ExorH1zx, which is chiefly to be attributed to their frequent uniformity of structure, and to their almost constantly upright position. The radicle usually first pushes from the epis- perm, or pericarp; andits end bursts open to permit the radicellar tubercle to escape. If the emission of the latter take place without remarkable exten- sion of the radicle, the edge ef the radicular opening is very narrow, and forms as it were a slight rim round the base of the radicel, or a lit- tle ring or disk, more or less developed. If the radicle extends before its end opens, it forms a sheath more or less long, which envelopes the base of the radicel; the latter becoming elongated to form the base of anew vegetable. But it fre- 69 quently happens that when several lateral radicels are sufficiently developed, the primary one with- ers and perishes, as does the Hypoblastus. The cotyledon increases more or less before it is perforated by the gemmule which it contains. When its perforation or rupture, which is always lateral, takes place next the summit, it is entirely converted into a cylindrical sheath enveloping the gemmule. When it opens at a distance from the summit, its upper part remains solid, and after- wards becomes enlarged in a greater or less degree; its lower part forming round the gemmule a sheath, proportioned to the elongation or dilata- tion it has undergone previous to being perforated by the latter. The extraordinary construction of the radicle of Embryones macropodi, called vitelliferous, ne- cessarily occasions some difference in the manner in which the radicels are formed. En fact the great body of the radicle called Hypoblastus, does not sensibly increase at all, and, enclosing no ra- dicellar tubercle, remains in statu quo, and the radicels spring from the surface of the cauliculus at its base. We may reduce to three principal heads the different modifications of germination in ENDO- RHIZÆ; 1. Immotive. 2. Admotive. 3. Remotive. 70 In the first, which is peculiar to Embryones macro- podi, or those furnished with an hypoblastus, the episperm remains fixed to the base of the young plant, by means of the hypoblastus. In the se- cond, the episperm encloses the head of the coty- ledon, and is retained laterally near the sheath of the latter. In the third, the episperm is carried up to an indeterminate distance from the primary radicel, by the elongation of the cotyledon, to the summit of which it remains fixed for some time. I shall conclude what concerns ENDORH1IZZÆ, by remarking that Gertner, the most laborious, and the most learned scrutinizer of the vegetable embryo, has himself been wrong in considering as monc- cotyledonous that of Zamia, Taxus, Aristolochia, Asarum, Hippuris, Loranthus, and Nepenthes ; so true is it, that the author of a work not only long, but full of difficulties can never hope to be exempt from error. The next lecture will chiefly apply to the em- bryo of ExoruH1z2, which constitute my second division of EMBRYONATE plants. NoTE.—My observations on this structure will be very brief as I shall reduce them to their most remarkable part. Of Exorhize.—The divisionof EMBRYONATÆ EXORHIZ&, is composed of mono-di- and polyco- 7i tyledonous ~plants; but a gradation founded on the number of cotyledons, cannot be the base of even a secondary division, because it would dis- turb the affinities of orders, and even of genera. Nevertheless, having here to speak only of the embryo, in some measure isolated, f shall divide my observations according to the above grada- tions. 1. The embryo of monocotyledonous Exorut- Zm is very rare. Itis epispermic in LENTIBU- LARIÆ and endospermic in Cyclamen and Cus- cuta.* It forms a body whose surface is perfectly continuous, and whose substance appears homo- geneous and entirely solid. At the period of ger- mination its radicular extremity enlarges in ‘Cyclamen, and elongates in the others, to become a root; the opposite extremity assumes in this genus and its allies the character of a radicular gemmule, and becomes elongated in Cuscuta into a simple thread which is the rudiment of the stem. The kernel of Lecythis is a fleshy amygdaline body, so solid and homogeneous that it is ex- tremely difficult to discover the two extremities. One of the ends forms at first a little protu- berance which after having burst the episperm, extends itself as root; the other produces a scaly gemmule, which, being developed, forms the a See tab. 3. fig. 6, 7, 8. 72 stem. The resemblance between this kernel and that of Pekea induces me to regard it as an en- larged radicle, or as an embryo which seems to consist of the radicle only. This body after ger- mination appears like a bulbshaped or tuberous ex- crescence at the bottom of the young stem. The kernel of the seed of Bertholletia resembles that of Lecythis; but I have not seen it germinate, Phe embryo of the plants of which I have been speaking, might perhaps be better named acoty- ledonous, since I never have been able to disco- ver any thing that can be considered analogous to cotyledon. Yet we see by what precedes, that it does not on that account cease to be Exorhizal. it confirms then, through the medium of Cy- clamen the affinity of LantizuLARim with AN- AGALLIDEÆ; an affinity that the astonishing sagacity of the celebrated Jussieu had before perceived, 2. Of various embryos, the dicotyledonous is the most common. The knowledge of its struc- ture does not require, at least very rarely, the aid of dissection or germination. One ofits ex- tremities being always undivided, forms the radicle, which itself becomes the root; the other presents two cotyledons resulting from its more or less profound division. 73 The cotyledons are usually equal; they never- theless undergo in some genera different degrees of inequality, and Trapa* affords an instance of of their greatest disproportion. Almost always their inner surfaces are mutually applied to each other ; very rarely they diverge more or less as in Thesium, many RANUNCULACES, certain VI- TIGINEÆ, Myristica, Ruizia, (fl. Per.) &c. In these plants the embryoniferous cavity is sim- ple; only in the two last genera, a protuberance of the endosperm separates the cotyledons, which in Ruizia are remarkably divided. In two species of Menispermum that I have not had occasion to observe, Gertner saw the cotyledons ledged in two distinct cells,’ only communicating towards the radicle. This last observation is the more surprizing as in other species considered as allies, such as Cis- sampelos® and Abuta, the embryo is curved like an horse-shoe in an endosperm of the same form, and has its two cotyledons entirely contiguous and applied face to face. We might to a certain extent oppose the Em- bryones macropodi of ENDORHIZ# to certain Em- bryones macrocephali of EXORHIZÆ. Geertner has distmguished the last by the sesquipedalian, but 4 See tab. 2. fig. 14, 15, 16. © See tab, 6. fig. 1, 2. € See tab. 6. fig. 7, S, 9 74 correct name of pseudomonocoiyledones. 1 shall describe a few of them, to enable you to avoid the errors into which their structure might lead you. They have the common character of union of cotyledons in a single body, which I name cotyle- donary body, I shall commence by CYcADEz, whose struc- ture is more simple and will serve to explain the nature of theirs. This order is as yet composed only of the two genera, Zamia and Cycas. Gærtner having only analysed some incomplete seeds of Zamia, is very excusable for having taken the endosperm for a vitellus, and a rudi- ment of embryo for the embryo itself. But what shall L say of those who, having in their hands complete fruits of this genus, have chosen to find in the imperfect figure of Zamia villosa an ana- logous situation between its embryo and that of PALMÆ; of PALMÆ, which by their flow- ers and fruit have no characteristic affinity what- ever with CYCADEZ. In a memoir which should have been printed before now, if I could support the expence of having the figures engraved, I hope to prove that CYCADEZ are inseparable from CONIFERS. 1. The embryo of Zamia* is reversed with re- gard to the pericarp, and occupies an axile cavity a See tab. 4. fig. 12, 13. 75 in a large endosperm, the orifice of which it seems to fill with the end next the radicle. It is straight, linear oblong ; the radicle is very short, rounded, obtuse, and terminated by a peculiar filament ; the cotyledonary body is oblong and becomes slightly narrower towards the radicle. A little above the latter, a longitudinal slit is observa- ble, which passes through it from one side to the other, and divides the attenuated base of the cotyledonary body into two pieces between which the gemmule is narrowly confined. 2. The embryo of Cycas* circinalis only differs from the preceding by the cotyledonary body be- ing proportionably larger, a little bent, and obliquely divided on one side near the summit. 3. The cotyledonary body of the embryo of Hippocastanum* is a spheroid which constitutes almost all the kernel; from one of its faces sud- denly springs a conical elongated process, curved in the shape of an horn, and directed towards the areola at the base of the seed, at the edge of which it terminates. Pretty near the middle of this corniform elongation exists a little longitu- dinal cleft so completely closed that it escaped the piercing eye of Gærtner ; this cleft contains the gemmule asin the preceding genera, and indicates * See tab. 5, fig. 4. » See tab. 3. fig. 17, 75 that the major part of the elongation belongs tothe body of the cotyledons, and that its extremity only forms the radicle. The embryo of Hippocastanum is exactly the reverse of that of Ruppia; their exterior con- formity renders this inversion striking, 4. The two cotyledons of the embryo of Casta- nea, have at the bottom only a slight point of union, taking place by the intervention of the neck of a little radicle, beneath which they extend so as just to conceal it. Besides this necessary uni- on, they contract another which sometimes com- mences near the first, and sometimes only takes place by their upper extremity. This last cohe- sion is now and then destroyed by germination. 5. The kernel of a seed of T'ropæolum® is an inverted embryo, and almost entire!y formed by the cotyledonary body. This is shortly ovoid ; its base is a little flattened by the pressure of the epispermic areola, and is divided into four thick teeth which by their approximation form a little interior cavity. In this is fixed an oblong corpus- cle attached by two opposite lateral points, but otherwise free. The inferior extremity of this corpuscle is a conical radicle terminated by a membranous filament, standing erect between the a See tab. 5. fig. 12, 18, 14. “1? “NX summits of the four teeth; the upper is the gem- mule, visibly terminated by the rudiments of two primordial leaves which are opposite, bistipula- ted, &c. Now let us compare together, for comparisons are a source fruitful in information, these Embry- ones macrocephali: let us even admit into this comparison the commencement of their germina- tion. Geertner was well aware that the union of two cotyledons in a single body does not establish the unity of cotyledon, Their gemination is easily demonstrated in the three first genera. In the embryo with two free cotyledons, where are the bases of the latter? Is it not at the top of the radicle and round the point of origin of the gem- mule? But the gemmule of that which we are examining springs from the bottom of the cleft that encloses it; two parts springing from the same point form this cleft by their approximation ; these two parts then are the two bases of the co- tyledons and prove the double nature of the latter. This gemination is not at first so evident in the two last genera. But, by reflecting on the dis- tiuct nature of the two points by which the coty- ledonary body is attached to the summit of the radicle, we easily perceive that the interval which separates them, answers to the cleft in the pre- ceding genera. 78 Germination will make this truth more appa- rent® By it the divided part, drawn out of the seed as it were by the radicle, becomes elongated. The cleft is sometimes extended into the cotyle- donary body; this elongation of the bases of the cotyledons renders them more manifest. By it, the two connective points which attach the radi- cle to the body of the cotyledons, form two prolon- gations which push the radicle out of its cavity, and of the seed, and assume the character of the bases of two cotyledons. En all, the gemmule pushes through one of the sides of the cleft, when vegetation takes place. ‘The cotyledons of the freely dicotyledonous embryo, are usually developed by germination at an indefinite time after the exsertion of the radi- cle. But when they are retained in their enve- lope like the cotyledonary body of which I have spoken, they also form two basal elongations which perfectly resemble those of this body, Such elongations, which may regarded as the petioles of the cotyledons, are particularly evident in em- bryos where these organs have their point of union, and their radicle re-entering or concealed between the bases of the cotyledons. CuruLI- FERÆ, or AMENTACE# with inferior ovarium, offer examples of this, a See tab. 6. fig. 12, and 13. 79 Since the cotyledons or the cotyledonary body may be retained in their envelope, and do not emit during germination more than a narrowed extension of their bases; so also and as it were by inversion, the great body of the radicle of Lecythis and Pekea remains enclosed in its integument, preserves there for a long time its form and its size, and then suddenly produces from its base an elongation which becomes root. The embryos of certain EXORH1IZZÆ which Ihave named Blastocarpi, germinate or commence ger- mination in a pericarp whilst attached to the plant which produced them. Many genera, like Rhizo- phora,* Sechium, Avicennia, Sphenocarpus (or Conocarpus racemosa, ) &c. offer examples of it. We sometimes also see fleshy fruit such as Citrus, kc. without apparent alteration, enclose seeds in a state of germination. 5. Gærtner has clearly demonstrated” that there certainly are embryos with more than two coty- ledons. The possibility of their existence is proved from time to time even by dicotyledonous plants, whose embryo sometimes assumes three cotyledons. That of the singular genus Cerato- phyllum* has constantly four, of which the two opposite are constantly smaller; its gemmule is a See tab, 6. fig. 3, b The celebrated Malpighi was, I believe, the first who noticed this structure, His words are, Hec (caro )—versus medium oblonga pronit foliola duodecim gracilia, que, germinante plantula, diducuntur. See Malp. anat. plant. p. 78. 30 the most compound one I know. The order of ConiIFER#& is that in which the greatest number of examples occur of a polycotyledonous embryo. The plurality of cotyledons exists there from three to more than a dozen. But the number is not very constant either in allied species or indivi- duals of the same species. The more we are versed in the interesting study of the characteristic affinities of plants, the more we are persuaded, with Adanson, that the groups indicated by Nature, sketched by that erudite bo- tanist, and made move perfect by a modern work above all praise, can never perhaps be united by amethod entirely natural, Jussieu, in founding his system on the solid bases of the insertion of parts, has exhibited a great proof of genius. But it seems to me that, perhaps seduced by the numeïical gradations of apetalous, monopetalous, and pelypetalous, he has admitted between the first and the last an interval which the separation of sexes could not itself weaken. Whatever may one day be their arrangement, those who occupy themselves with it will be perhaps surprized to perceive that it is the embryo of CONIFER:x, that is tc say of the order most abounding in Polycotyle- .dones, which, anone Exoraizam, has the greatest relation with the monucotyledonous embryo of a See tab. 2 fige 170 PRIMARY DIVISION OF PLANTS. EXEMBRYONATÆ: no sexes: produc- ing sporules : hav- ing no embryo. EMBRYONATE: having sexes, seeds & embryo. | I. ARHIZÆ ; no embryo—no radicle. II. ENpoRHIz&; the whole surface of the embryo undivided. Radicleby germination burst or perforated at the apex by an internal tubercle which increases in size, and becomes the root of the young plant, Cotyledon one, first concealing the extra axile gemmule in a basal, perfectly closed cavity, then emitting it through a rupture in its side. Rarely the radicular body of the em- bryo (macropodus) is larger than the rest, and unchanged by germination ; the cauliculus then putting forth radi- cellar tubercles above it. Ill. SYNORHIZÆ; Embryo divided at one extremity or at the sides; apex of the radicle united to the upper and dissimilar part of the endosperm, which, being burst by germiuation, pushes forth an internal tubercle, increasing and becoming the root of the young plant. Cotyledons two or more, between the centre of whose bases the gemmule rises or is situated. Obs. To this belong only Cycadeæ and Conifere, IV. EXORHIZÆ; Embryo divided at one extremity or (rarely) at the side; the whole radicle itself extending, withoutrup- ture of its apex, as the root of the young plant. Cotyledons two, sometimes more, between whose bases, in the centre, is the point from which the present or future gemmule is to spring. Rarely no distinct cotyledon. EXPLANATION OF NEW TERMS. ACOTYLEDONOUS (Embryo); without any true cotyledon. The Acotyledones of Jussieu answer to my Exembryonate. ACHENIUM; a fruit which is dry or without any evident flesh, indehiscent, monosper- mous; its episperm distinct from the endocarp. AMPHITROPOUS (Embryo) ; curved in such a way that its two ends are directed towards the hilum, and almost equidistant from it. AMPLEXATILIS (Embryo); when the radicle surrounds all the rest. ANTITROPOUS (Embryo); having a direction con- trary to that of the seed. AxIs of the Seed ; a line supposed to be drawn through its middle longitudinally, from its base to its summit. This word is equally applicable to the endosperm, pe- ricarp, &c. 83 AXILE (Embryo); internal and situated longitu- dinally in the axis of the endosperm, BLASTUS; a body usually cylindrical, fixed to the hypoblastus, and made up of the cau- liculus and cotyledon: thus named, be- cause it is the only one of the two bodies forming the embryo macropodus which is developed during germination. BLASTOCARPIC (Embryo); germinating in the pericarp. BracHypopus (Embryo); when the radicle is short; this is opposed to the word radi- culosus. CELLULAR (Pericarp); having the appearance of being plurilocular, but proceeding from an unilocular ovarium. CooRDINAL; of the same natural order. CAULICULUS; part of the embryo which unites the radicle to the cotyledon or cotyledons, DRUPACEOUS ( Pericarp); when the endocarp is hard, and covered with a thick integument which is separable or distinct from it and scarcely fleshy. EMBRYONATUS; provided with, or proceeding from, a true embryo. ENDOCARP; interior part of a pericarp, imme- diately forming the seminiferous cavity. G 2 84 ENDORHIZUS (Embryo); when the radicle does not itself form the simple or multiplied ru- diment of a root, but encloses it. This word is also applicable to the plants which produce such an embryo. ENDOSPERM; a body distinct from the embryo, and with it formmg the kernel of a seed. Jussieu called it Perisperm; Gertner Albumen. ENDOSPERMIC (Embryo); accompanied or cloth- ed with an endosperm. EPIBLASTUS ; anterior appendage of the embrye of some GRAMINEZ. EPIcARP; skin or exterior membrane of the pericarp. EPISPERM; peculiar integument of the seed. EPISPERMIC (Embryo); forming by itself the whole kernel of a seed, and immediately covered by the episperm. EXORHIZUS (Embryo); when the radicle elon- gates and becomes itself the root. This also applies to the plant which produces such an embryo. EXTERNAL (Embryo); situated on the outside of the endosperm. 85 FRUCTUARIUS; of or belonging to the fruit. GEMMULATION ; developement of the gemmule. GEMMULE; bud of the embryo; part of the embryo contained between the bases of the cotyledons, or enclosed in a cotyledon, and growing during germination in a con- trary direction to the radicle. Plumula of authors. Hererorpous (Embryo); of a form different from that of the containing part. HETEROTROPOUS (Embryo); whose direction crosses obliquely or transversely the axis of the seed, neither of its two ends being exactly opposite the hilum, Homoipous (Embryo); having the same form as its integument or covering, Homotropous (Embryo); not being straight, but having the same direction as the seed. HYPOBLASTUS ; basal or radicular body of the embryo of Endorhizæ macropode, whose form it determines ; undergoing no orga- nic developement during germination. INTERNAL (Embryo); enclosed in the endosperm. LOCULICIDAL; when dehiscence takes place by the middle of the cells. 86 MACROCEPHALUS (Embryo); when the cotyle- dons are united into a body much larger than the rest. Macropopus (Embryo); when the cauliculus bears the cotyledon, and springs abruptly from the body of the radicle, which is con- siderably enlarged. NUCULANIUM ; fruit whose fleshy pericarp forms several distinct nuts. NUCULE;; each nut of a nuculanium. ORTHOTROPOUS (Embryo) ; straight, and having the same direction as the seed. PERICARPIC (direction); with respect to the pericarp. PERITROPAL (seed); directed from the axis towards the sides of the pericarp. PLEUROGYNOUS (insertion); on the body itself of an ovarium superum. PopOSPERM; extension or projection of the trophosperm, attaching a seed to the lat- ter. Umbilical chord of authors. RADICEL; rudiment of a root formed by the elongation of the interior substance of radicle, or of the bottom of the cauliculus of Endorhize. C7 RapicuLosus (Embryo); of Endorhize with a long radicle, or with a gemmule ata considerable distance from the end of the radicle. BRapicuLopA; base of the cauliculus or inferior extension of the blastus of GRAMINEZ; enclosing one or more radicellar tubercles. SARCOCARP ; parenchyma of the pericarp. SEPTICIDAL; pericarp opening by the middle of the dissepiments which are then divided into two plates, SPERMIC (direction); with respect to the seed. SPiLUS ; hilum of the seed of GRAMINEA, indi- cated by a brownish spot or reddish line situated on the interior face of the seed. SPORULE; body reproducing plants of Agame or Exembryonate. SYNZYGIA; point of union of the two cotyledons of the embryo of Exorhize. TROPHOSPERM ; interior part of the pericarp to which the seed is attached. Placenta of authors. EXPLANATION OF THE PLATES. PLATE I. 1. Vertical section of an apple. a, fleshy tube of the calyx. 6, junction of the latter and the epicarp. c, sarcocarp. d, endocarp. e, seeds. 2. Tranverse section of the same. a, sarcocarp. b, cell. 3. Capsule of Polemonium cæruleum (from Mirb.) divided transversely. a, dissepiment. 8, cell. 4. Transverse section of the nut of Corylus Avellana, 5, A, Siliqua of Arabis turrita. 5. B, Seed of the same. a, trophosperm. 6, hilum, 6. Capsule of Crocus stellaris. a, trophosperm —dehiscence loculicidal. 7, Achenium of Helianthus annuus, 8. Capsule (Pyxis Mirb.) of Anagallis arvensis, shewing the circumscissile mode of dehiscence, 9. Capsule of Antirrhinum majus—dehiscence an orifice. 89 10. Capsule of Reseda alba.—dehiscence an orifice. 11. Capsule of Campanula obliqua—dehiscence a rupture. 12. Capsule of Silene bupleuroides--dehiscence valvular, taking place at the apex only. 13. Utriculus of Amaranthus hybridus,—de- hiscence circumscissile, PLATE IT. 1. A.& B. 2. Carex arenaria, 3, Achenium of Thesium alpinum. 4, The same divided vertically. a, tube of the calyx, 6, point of union of the latter and the pericarp. c,sarcocarp. d,endocarp. e, seed. 5. Achenium of Salvia horminum. 6. The same divided vertically. a, cotyledon. b, cauliculus. 7. Embryo of the same. a, cotyledon. 6, ra- dicle. S. Capsule of Rhododendron ponticum. a, top of the axile trophosperm,—dehiscence septifra- gal. 9, Legumen of Ornithopus intermedius (Roth), —dehiscence, solubility by articulation, 10. Capsule of Euonymus europæus. a, tro- phosperm separating from the inner edge of the dissepiment, and giving the seed the appearance 99 of being suspended. c, the seed covered by its arillus b. d, arillus expanded about an abortive. seed. 11. Seed of the same taken out of the pericarp. a, the trophosperm. c, the top of the seed seen beyond the edge of the arillus. b. 12. Seed of the same with the arillus pulled off, 13. The same divided vertically. a, endosperm. b. embryo. 14. Embryo of Trapa natans. (from Gert,) a, the large cotyledon. b, radicle. 15.—16. Radicle of the same magnified. c, e, small cotyledon. d,radicle. f, gemmule. 17. Embryo of Ceratophyllum demersum, (from Mirb.) 18, Transverse section of the seed of Ipomoea purpurea, PLATE III. 1, Legumen of Lathyrus latifolius.—dehis- cence sutural. 2. Spontaneous excoriation of Euphorbia para- lias. 3. Achenium of Cherophyllum aromaticum. (from Mirb.) 4, Capsule of Ipomoea purpurea, transversely divided. (from Mirb.)—dehiscence septifragal. 5. A small branch of Leontice thalictroides (from Bauer). a, remains of the ruptured ovarium. b, seed. c, abortive seed. 91 6. Seed of Cuscuta Europea. a, hilum, 7. The same divided. a, Episperm. 45, gela- tinous endosperm: the embryo just visible through it. 8. Embryo of the same. 9. Seed of Plantago lanceolata. 10. Vertical section of the achenium of Smyrnium Olusatrum. 11. Section of the achenium of Potamogeton fluitans not quite ripe. 12. Achenium of Rosa caucasea. 13. Vertical section of the berry of Ribes uva crispa. (from Mirb. ) 14, Seed of Citrus medica. a, chalaza. 15.—16. Vertical section of Viscum album. (from Mirb,) a, b, embryo. 17. Vertical section of the seed of Æsculus Hippocastanum. a, gemmule. PLATE IV. 1. Vertical section of the nut of Saururus cernuus. a, section. 06, embryo. (from Mirb.) . Seed of Zingiber nigrum. . Section of the same. a, vitellus. . Embryo of the same seated in the vitellus a. . Embryo of the same without vitellus. The same vertically divided (all from Mirb.) . Seed of Commelina tuberosa. . The same divided vertically. . Embryo of Cabomba aquatica. (from Richard) © do Ni © P € D 92 10. Fungilliform embryo of Musa coccinea. (from Mirb.) 11. The same divided vertically. 12. Section of the fruit of Lamia spiralis. 13. Embryo extracted. (from Mirb.) 14 —15. Embryo of Ruppia maritima. (from Richard) 16.—17.- 18. Seed of Hydrocharis Morsus Rane. (from Richard) 19.—20. Embryo of Zostera marina, (from Richard) PLATE V. 1. Section of the anterior face of the embryo of Hordeum vulgare. a, radicellar tubercles. 2. Vertical section of the same. a, gemmule. 3. Seed of the same in a state of germination. a, lateral tubercles just beginning to break through the episperm. 4. Section of the seed of Cycas circinalis. (from Mirb.) a, endosperm. b, embryo. 5.—6. Kernel of Nelumbium asiaticum. (from Richard) 7.—8.—Kernel of Nymphozanthus vulgaris (Nuphar lutea.) (from Richard) 9. Kernel of Castanea vesca. 10.—11. Sections of the same. 12. Section of the pericarp of Tropeolum majus. 13. Seed of the same. 14. Section of the last. 93 PLATE VI. 1.—2. Seed of Menispermum Cocculus. (from Gert.) 3. Commencement of germination of Rhizo- phora gymnorhiza. (from Gert.) 6. calyx. €, pericarp. d, cotyledons. (Gert. ) 4, Section of the kernel of Pekea tuberculosa. (from Richard) 5.—6. Kernel of Zannichellia palustris. (from Richard) | 7. Pericarp of Wal-tiedde; a species of Cis- sampelos. (from Gert.) 8. Section of the seed, aE mbryo— of the same. 10. Surface of the embryo of Oryza sativa. 3, hypoblastus, c, epiblastus. d, radiculoda. 11. Section of the same. a, blastus. 6, hypo- blastus. c, epiblastus. d, radiculoda. ee, radi- cellar tubercle. f. pericarp. g, episperm. (testa.) 12. Germination of Quercus pedunculata. (communicated by M. Richard.) a, b, cotyledons. c, d, elongations of the cotyledons. e, radicle. f, cauliculus developed into a stem. 13. Germination of Castanea vesca. (communi- cated by M. Richard) letters same as in fig. 12, INDEX OF NATURAL ORDERS AND GENERA. Abuta = Acantkus Adoxa ‘Alisma - Alismaceæ Allium - Amentaceæ Anagallis - Anagallideæ Anguillaria Annona - Annonaceæ Apocineæ - Aristolochia Aroidee - Arum - Asarum - Atriplices - Avena Avicennia - Aucuba Page XV. 12, 23%87, - - 32, 23, DA 24 95 Cruciferæ - > 2 2 3 L. 2 - Page. Bertholletia = = - - = ~62,- 72 Brunellia - - = = 2 a ts 12 Bucida = ë = a 2 = “ 27 Butomeæ - - - - - - - xv. 50 Cabomba - - : 2 = à - 51, 62 Calladium - - 4 < 3 = : 43 Callitriche - = = = = 2 - 22 Cannabis - - : = = =: à 27 Caprifoliaceæ - - = - à -15, 24 _ Carex - - : > a x = 13 Caryophyllaceæ - = - : = a 37 Castanea - = = a 2 a 2 "6 Casuarina - - - = à fe 33 Ceratophyllum - = = DE - 36, 79 Chloranthus - = > : : 94 Cissampelos - L 2 = Ss - 317, 73 Citrus - = = 5 = - 7 "9 Cneorum - : = 2 _ a L 37 Codonium - - 2 À à a 5 21 Coix - - - - = : = : 48 Colchicaceæ - = = z 7 : 12 Commelinee - Pa" : a - 36, 50 Composite - - = = - 11, 23, 35 Coniferæ - - - - - 33, 46, 74, 80 Conocarpus - - - : E "9 Convolvulaceæ - - - - aes 32 Cratægus - - : = . c 24 Crescentia - - E = A 2 L 31 Cucurbitaceæ - = Cupulifere - = a Cuscuta - à i Cycadeæ - £ Z Cycas : ss > Cyclamen - a Cyperaceæ - aus Daphne Laureola = Daphne Mezereum - Dioscorea - - : Dipsaceæ - - - Elæagnus - - - Eleusne - bs Embryonatæ - Endogenæ - - - Endorhizæ = = Ephemerez - = Eriocauleæ = - - Euonymus - - Euphorbiaceæ Exembryonatæ - Exogene - - - Exorhize - - - Fluviales = - Globularia - - - Graminez xvi. 13, 16, 66, 67 96 = = xvi. 36, 50, 66 = oe SM Anas a Es - = 43. 46, 47, 48 - 12, 36, 50, 51, 62 36, 48, 50, 51, 52, 58, 65, 97 Page. Guaiacane - - - - - - - 23 Halesia - - - = - ~ - 38 Haloragis - - - - - - - 24 Hippocastanum - - - - 34, 37, 38, 75 Hippophae - - - - - - - 23 Hippuris - - - - - - 24, 70 Hordeum - - - - - - - 48 Hydrocharideæ = - - - - 4, 5, 36, 50 Hydrocharis - - - - - 52, 53, 63 Hydropeltideæ - - - - - 50, 57 Hygrobiæ - - - - - - - 24 Ipomæa - - - - - - - 10 Irideæ - - = = - - - 10 Jasmineæ - = - = - “ = os Jasminum - - - - = - < 14 Jeffersonia - - = = = > : 9 Joncagineæ - - - - xv. 12, 23, 50 Juncinee - - - - - - - 12 Kiggelaria - = E - à = 9, 14 Kobresia - - - - - - - 13 Lacistema - - - = - - - 18 Lathræa - - = - - - - 27 Laurineæ - - - - - - - 15 Lecythis = - - - - 62, 71, 72, 79 Lentibulariæ - - - - - 192 Leontice - - - - - - - 15 Loranthus - - - - - - 24, 70 Magnolia - - + - - - 12, 18 Malpighia - : - - - - - 15 Melampyraceæ Menispermum Mespilus Momordica Monocotyledones Monotropa Musa Myriceæ Myristica Myrtoideæ Naias Myriophyllum Nelumbium - Nepenthes Nuphar Nymphea Nympheeaceze Nymphozanthus Nyssa Onagræ Operculariæ Orchideæ Oryza Palmæ Papaver Parnassia Pekea Piperaceæ Pistacia Plantago 98 52, 55, 64 : 36, 70 TS - 56, 58, 64 50, 57 - 56, 57 - - 37 : - oa - 6 -62, 64, 65, 72, 79 - 50, 57 - 22 2 É 24 99 Page. Platanus - - - - - 36 Plumbagineæ - - - - 22 Pomacee = - - - - 23 Potamogeton - - = 22,029: (62 Potamophilæ - - - Xv. 23, 36, 50 Proserpinaca - "4 - - - 24 Prunus - - - = - 3 Pyrus = 2 = - - 24 Ranunculaceæ - - - - 12, 73 Reseda - - - = - 8 Rhamnoidee = - - - 15 Rhizophora - = - - - 79 Rhododendron - - - - 10 Rhus > L = - - 22 Rosa - = = 2 = 35 Rosaceæ = = : = = 22 Rubiaceæ - - - 14, 15, 25, 35 Rubus - = = = - 12 Ruizia - - - - - 73 Ruppia - - 23, 52, 62, 63, 65, 76 Rutaceæ - - = - - 14 Ryana - - - - - 8 Samolus = = Eu 2 ; 36 Sanguisorbeæ - - - - 24 Sapindus - - - - - 34 Sapotæ - - - - - 23 Saurureæ - - - 36, 50, 57, 62 Schænus - = = - - 13 Scleria - = a - - 50 Scrophulariæ - - 2 : ao 4 Secale = Sechium Sphenocarpus Simarubaceæ Solaneæ - Styraceæ Sinanthereæ Taxus Ternstromia Thesiaceæ Thesium Thevetia Thymaleæ Trapa Triglochin Triticum Tropæolum Typhineæ Umbelliferæ Viscoideæ Viscum - Vigitineæ Wal-tiedde Zamia - Zannichellia Zanthoxylum Zingiberaceæ Zostera - - 202, 10, if 23, 47, s 50, 51, 52, 54, 56, 63, 62 a, OF THE UNIVERSITY OF ILLINOIS a9 = ea) ne nits ed LIBRARY OF ThE: UNIVERSITY OF ILLINOIS ae, à LU LES | Null | oe i f Be) ei er é Th db! De OF THES 4 ‘UNIVERSITY OF ILLINOIS * Ni } | [AR CE PP aN (AY vi} RS D TT 4 A aA Mes A, À UNIVERSITY OF ILLINOIS-URBANA 581.3R38AEL C002 OBSERVATIONS ON THE STRUCTURE OF FRUITS TN 01 31