.-.4. ^^%;^^; '•?>^'^--^i*^-'-^ =^?h--:x-^ ^''^T^i X -r r ->■ ^ r'^f^^"* ■v^yi^ ^JiW v:^<^-^l/ ^.-v'" '<^ < ^ \.fj .A' ^ lit V 1 i^r^i NV^»-^ V.-AsJl^r f. '^hst^s XT,dsS3 JOURNAL ELisfiA Mitchell Scientific Society VOLUME XXXI 1915 ISSUED QUARTERLY PUBLISHED FOR THE SOCIETY Edwaeds & Beoxjghton Printing Co. Raleigh, N. C. Mil iqiS Jj-^^Ajt^ I- 3( TABLE OF CONTENTS PAGE Proceedings of the Fourteenth Annual Meeting of the North Carolina Academy of Science 1 An Outline Bearing on the Theory of Descent — J. J. Wolfe 12 Eadio-activity and the Periodic System — F. P. Y enable- 27 A List of Homoptera in North Carolina — Z. P. Metcalf 35 The Seasonal Distribution of the Araiy-AVorm Moth at Raleigh — C. S. Brimley 61 Cooperation in Matters Chemical (Presidential Ad- dress)— Clias. H. Herty 65 The Merit System in Highway Work — Joseph Hyde Pratt 86 Our Mountain Shrubs — IF. C. Colder 91 Observations on the Lawns of Chapel Hill — W. C. CoUr and E. 0. Randolph 113 The Vascular Response of the Kidney in Acute Ura- nium Nephritis — The Influence of the Vascular Response on Diuresis — Ifm. deB. MacNider 122 Notes on New and Rare Species of Fungi Found at Asheville, N. C.—H. C. Beardslee 145 The Influence of Radium Rays on Germ Cells and Em- bryonic Tissues. — ir. C. George 150 Winter Grasses of Chapel Hill— TF. C. Coker 156 PAGE The Lawn Problem in the South— 11\ C. Coker 162 The Collection and Cultivation of Crude Drug Plants in Xorth Carolina — John Grover Beard 167 Publications of the United States Department of Agri- culture on Drug Plants 180 Index to Volumes I to XXXI 182 VOL. XXXI JULY, 1915 No. 1 JOURNAL OF THE EusHA Mitchell Scientific Society ISSUED QUARTERLY CHAPEL HILL, N. C, U. S. A. TO BE ENTERED AT THE POSTOFFICE AS SECOND-CLA88 MATTER Elisha Mitchell Scientific Society J. M. BELL, President A. H. PATTERSON, Vice-President T. F. HICKERSON, Recording Sec. F. P. VENABLE, Perm. Sec. Editors of the Journal : W. C. COKER J. M. BELL - A. H. PATTERSON CONTENTS PROCEEDINbs OF THE FotJBTEENTII AnNTJAL MeETING OF THE NoETn Carolina Academy op Science . . 1 An OuTi.iNE of Modern Work Bearing of the Theort of Descent — J. J. Wolfe 12 Radio-Activity and the Periodic System 27 A List uk liuMoi'JKiiA in North Carolina — Z. P. Metcalf 35 Tjii: tSEAauNAL DisTiiiBUTioN of TJiE xiimv-AVoinr Moth at Raleigh: — C. S. Brimley CI Journal of the Elisha Mitchell Scientific Society — Quarterly. Price $2.00 per year; single numbers 50 cents. Most numbers of former vol- umes can be supplied. Direct all correspondence to the Editors, at University of North Carolina, Chapel Hill, N. C. JOURNAL OF THE Elisha Mitchell Scientific Society VOLUME XXXI JULY. 1915 No. 1 PROCEEDINGS OF THE FOURTEENTH ANNUAL MEETING OF THE NORTH CAROLINA ACAD- EMY OF SCIENCE HELD AT WAKE FOREST COLLEGE, WAKE FOREST, N. C, FRI- DAY AND SATURDAY, APRIL 30- MAY 1, 1915 The Academy was called to order by President J. J. Wolfe at 2 :50 P. M., with 21 members and 10 visitors pres- ent. Reading of papers was begun and continued until 9 had been read and discussed. President Wolfe then an- nounced the following committees: Nominations, C. Cobb, F. Sherman, Jr., J. F. Lanneau ; Auditing, A. S. Wheeler, B. Cunningham, C. S, Brimley ; Resolutions, W. A. Withers, A. H. Patterson, Z. P. Metcalf. The Academy then ad- journed at 5 :30. The Executive Committee — President Wolfe, Vice-Pres- ident Patterson, Secretary Gudger, ex officio, and Prof. W. A. Withers — held its annual meeting immediately after ad- journment. The following applicants for membership were unanimously elected : 1. F. E. Carruth, Assistant in Chemistry, N. C. Experiment Station, West Raleigh. 2. R. H. Field, Assistant in Zoology and Entomology, State Agri- cultural and Mechanical College, West Raleigh. 3. S. W. Geiser, Professor of Biology, Guilford College. 4. T. F. Hickerson, Professor of Civil Engineering, University of North Carolina. 2 Journal of the Mitchell Society \_July 5. R. W. Leiby, Assistant Entomologist, State Department of Agriculture, Raleigh. 6. Mary Lyon, Professor of Science, Southern Presbyterian Col- lege, Red Springs. 7. E. T. Aliller, Professor of Engineering, Trinity College. 8. J. K. Plummer, Soil Chemist, State Department of Agriculture, Raleigh. 9. Elizabeth B. Potwine, Instructor in Mathematics, State Normal College, Greensboro. 10. H. Spencer, Assistant in Zoology and Entomology, State Agri- cultural and Mechanical College, West Raleigh. A letter from the Secretary of the Faculty of the A. & M. College was then read invitiug the Academy to hold its next annual meeting at that institution in 1916, On motion the invitation was unanimously accepted. The Secretary then gave his report as to (1) membership, (2) finances, and (3) the matter of raising the dues. These matters were dis- cussed at some length and recommended to the careful con- sideration of the Academy at its annual business meeting. The Committee then adjourned. At 8 P. M. the Academy met in evening session in "Win- gate Memorial Hall. After a cordial welcome to Wake Forest College delivered by Dean Charles E. Brewer, Presi- dent J. J. Wolfe delivered his presidential address, ''The Status of the Theory of Descent," Next Prof, John F. Lan- neau delivered a lecture on "The Cosmoid" with a demonstra- tion of an apparatus of his own design. Following him Prof. A. TI. Patterson gave a demonstration and explanation of the working of a new form of humidifier of Xortli Caro- lina make. His title was "The Importance of Humidity in Health and the Arts," At 9:20 Saturday morning the Academy convened in an- nual business meeting with 19 members present. The min- utes of last meeting were read and approved and the report of the Executive Committee as to the election of new mem- bers and the choice of the next place of meeting was had. Notice was ordered to be entered in the Proceedino;s of the 1915^ Peoceedings N^. C. Academy of Science 3 invitation to the recent inauguration of Prof. E. K. Graham as president of the University of North Carolina, and of our representation there by President Wolfe. The Secretary then made his annual report as to membership ; that on Janu- ary 1, 1914, there were 78 members, and that dviring the year there were 4 new members elected and 13 dropped be- cause of removal from the State, non-payment of dues, etc., leaving 69 members in good standing on January 1, 1915. The Treasurer then read his itemized financial statements as follows : Report of E. W. Gudgek, Teeasueee^ 1914-1915. Apeil 23, 1915 RECEIPTS Balance, last audit $ 186.06 Dues since last audit 67.00 Interest Savings Bank 4.46 Total Receipts 257.52 Less Expenses 96.55 Balance 160.97 RESOURCES Savings Bank Balance $ 114.47 Checking Bank balance 46.50 Total 160.97 Dues unpaid (about) 25.00 Stamped envelopes (about) 7.00 Estimated Resources 192.97 Estimated Debts 95.00 Estimated Balance 97.97 EXPENSES Proceedings, 1914 $ 75.00 Secretary's expenses, Durham 4.90 Postage 5.50 Typewriting and clerical help 2.40 Printing 8.75 Total Expenses 96.55 4 Journal of the Mitchell Society [JuIt/ OUTSTANDING DEBTS Proceedings, 1915 $ 75.00 Printing 5.00 Miscellaneous (about) 15.00 Total (about) 95.00 Tlie Treasurer next drew attention to a comparative financial statement synopsized on the blackboard showing the receipts, expenditures, and balances since 1907-08, and mak- ing it clear that our yearly receipts do not meet our yearly expenses, and that the deficit has had to be met annually out of our gradually diminishing savings bank account. Con- siderable discussion was then entered into on the question of raising the dues. This course, however, was deemed imwise and it was thought best to institute a vigorous campaigTi for new members that the income from initiation fees might swell the cash receipts at the same time that new blood was infused into the Academy. On motion, unanimously adopted, the President was em- powered to appoint a committee composed of one or more members representing each locality where meetings are held, with two members for the State at large, whose duty it shall be to make every efi'ort possible to increase the membership of the Academy. President Wolfe announced as the Com- mittee for 1916: Chapel Hill, A. H. Patterson; Durham, E. T. Miller; Greensboro, Miss Gertrude !Mendenhall; Guil- ford College, John S. Downing; Raleigh, C. S. Brimley and Z. P. Metcalf; Wake Forest College, John F. Lanneau; State at large, Franklin Sherman, Jr., and tlie Secretary, ex ojficio. Reports of committees being next in order, the auditing committee reported the Treasurer's books, accounts and year- ly statement to be correct. The nominating committee next reported and the following officers were elected for 1915-10: President, A. S. Wheeler, Professor of Chemistry, University of North Carolina. 1915^ Pkoceedings N. C. Academy of Science 5 Vice-President, W. A. Withers, Professor of Chemistry, State Agri- cultural and Mechanical College. Secretary-Treasurer, E. W. Gudger, Professor of Biology, State Normal College. Additional Members Executive Committee : Z. P. Metcalf, Professor of Zoology and Entomology, State Agricultural and Mechanical Col- lege. W. C. Coker, Professor of Botany, University of North Carolina. E. T. Miller, Professor of Engineering, Trinity College. The resolution committee presented the following report: The North Carolina Academy of Science, assembled for its four- teenth annual session, finds itself under renewed obligations to Presi- dent Poteat, Dean Brewer, and the Faculty of Wake Forest College for the considerate manner in which they have provided us with a meeting place, and the kindly and gracious manner in which the citizens of Wake Forest have entertained us in their homes. The Academy feels itself the richer for having heard the scholarly address of President Wolfe, and the Academy, which already owes a great debt to its Secretary-Treasurer for the able manner in which he has conducted his office, feels itself again with greatly increased obligations on its hands. Therefore be it resolved by the North Carolina Academy of Science, that President Poteat, Dean Brewer, the Faculty of Wake Forest College, the citizens of Wake Forest, President Wolfe and Secretary Gudger have combined to make this one of the most profitable meetings of this Academy. The report of the legislative committee on ventilation was then called for and the committee then discharged from further duty. At 10 o'clock the reading and discussion of papers was then resumed with some 25 members and visitors present. The session continued until all had been read when adjourn- ment was had at 1 :20 P. M. Of the 23 papers on the pro- gram only three were read by title. The membership of the Academy at the present time is as follows (those present at this meeting being indicated by a*): 6 Journal of the Mitchell Society \_JuJy Allen, W. M.; Balcomb, E. E.; *Brimley, C. S. ; Brimley, H. H Bruner, S. C; Cain, William; *Carruth, F. E.; Clapp, S. C; *Cobb, Collier; Cobb, Wm. B.; Coker, W. C; Collett, R. W. ; *Cunningham Bert ; Dixon, A. A. ; Downing, J. S. ; Edwards, C. W. ; *Farmer, C M.; *Field, R. H. ; Fulton. H. R. ; Geiser, S. W. ; *George, W. C. Gove. Anna M.; *Gudger, E. W.; Hammel, W. C. A.; Harding, W, T.; Herty, C. H.; *Hickerson, T. F. ; Hobbs, A. Wilson; Hoffman S. W.; Holmes, J. S. ; Hutt, W. N. ; Ives, J. D. ; Kilgore, B. W. *Lanneau, J. F. ; Lay, George W. ; *Leiby, R. W. ; Lewis, R. H. Lyon, Mary; Mclver, Mrs. Chas. D. ; MacNider, W. deB. ; Mac- Nider, G. M.; Markham, C. B.; Mendenhall, Gertrude, W. ; *Metcalf, Z. P.; *Miller, E. T.; Mills, J. E. ; Newman, C. L. ; *Patterson, A. H. ; Pegram, W. H.; *Plummer, J. K. ; *Poteat, W. L. ; Potwine, Elizabeth B. ; Pratt, J. H. ; Ragsdale, Virginia ; Randolph, E. Oscar; Rankin, W. S. ; Robinson, Mary; *Sherman, Franklin, Jr.; Shore, C. A.; Smith, J. E. ; *Spencer, H.; Stiles, C. W.; Strong, Cora; *Totten, Henry R. ; Venable, F. P. ; *Wheeler, A. S. ; Williams, L. F. ; W^ilson. H. V. ; Wilson, R. N. ; *Withers, W. A. ; *Wolfe, J. J. The following papers were presented : DESMOTROPY ALVIX S. WHEELER The first case of keto-enol isomerism among the phenols of the naphthalene series was recently reported by Willsaetter and Wheeler. Juglone, a dyestuff in green walnut shells, yields on reduction 1, 4, 8- trihydroxynaphthalene, melting at 152°. After once being melted, it melts thereafter at 96°. Since this type of compounds is very sensitive to alkalies, weakl}' basic reagents as semicarbazine and phenylsemi- carbazine were emploj-ed to detect the carbonyl group. The lower melting product was found to be the ketonic form. Some work, not yet published, on 1, 4, 5, 6-tetrahydroxynaphthalene reveals another case of this nature. Here however it has been impossible to separate the two forms, the compound melting at 154° responding readily to both enolic and ketonic reactions. Numerous isomerisation methods fail to reveal another form. The application of Knorr's ferric chloride method and Kurt Meyer's bromine method to approximate the relative amounts of the isomers present is not practicable to the above cases. Ferric chloride oxidizes the compounds to quinones wliile bromine enters the ring of either form. 1915^ Peoceedia^gs IST. C. Academy of Science Y THE H-H WATERWHEEL AND PUMP FOR FARM WATERWORKS T. P. HICKERSON The Hutchison-Hickerson Waterwheel and Pump, recently in- vented by R. B. Hutchison of Wilkinsburg, Pa., and T. F. Hickerson of Chapel Hill, N. C, is a discovery of a new application of the old principle of the overshot wheel in the design of a small easy run- ning combination Wheel and Pump and Stand (made in the factory complete for installation) to utilize the flow and fall of small brooks as power for operating continuously a pump which pushes pure spring water to higher elevations. The remarkable simplicity, adaptability, and reliability of this machine brings it in direct competition with Hydraulic Rams, all of whose defects seem to be met satisfactorily by the Wheel and Pump. One dozen of these Wheels and Pumps have been introduced in North Carolina during the past year. Among these is one which de- livers every day through a vertical height of 45 feet 500 gallons of spring water for a large farm home, where the power of the stream •which operates the wheel is only 1-100 of a horse power. ON LEIDY'S OURAMOEBA AND ITS OCCURRENCE AT GREENSBORO, N. C. E. W. GUDGER In the fall of 1914, considerable numbers of large and active Ouramcebas were found at Greensboro. The Amoebas themselves and the locality in which they were found were described. Their activities both in feeding and moving were discussed, and it was noted that there was no reversal of polarity, the tail-feather-like mass of fungous hyphae always remaining posterior. The history of this interesting organism was then reviewed, and the conclusion arrived at that Ouramoeba (tailed Amoeba) is nothing but an ordinary Amoeba which has ingested fungous spores which have germinated and formed a mass of mould hyphae which projects from the posterior end of the animal. The full paper will be published shortly. SOME IGNEOUS ROCKS OF MOUNT COLLIER JOHN E. SMITH Mount Collier is in Orange County, N. C. ; about 5 miles west of Chapel Hill. It is typical of those igneous monadnocks of the eastern Piedmont, most of which rise to a common level about 200 feet above the peneplain. It was formerly much higher and of greater extent this is shown by the position of parts of the mountain that have been 8 Journal of the Mitchell Society [July separated from it by erosion, also by the fact that Ball Mountain, in Davidson and Rowan counties, of similar rock and structure has been cut by a river (Yadkin) which flows through it. That the upland level of the region is a peneplain is also proved by the presence of smooth, rounded quartz pebbles on this plain. The mountain consists chiefly of dark rhyolite which made its way upward along the contact between the ancient crystalline schists north of it and the granite on the south. On each if its slopes flow structure has been observed in the weathered rock and in many places where it is fresh. It is called Mount Collier in honor of Professor Collier Cobb who, in 1892, was the first to recognize its igneous origin. (Specimens and structure sections were used in presenting the paper.) SOME OBSERVATIONS ON THE RED CEDAR H. R. TOTTEN Junipcrns virgiiiiana is our common cedar and is the only species of Junipcrus that is at all abundant in North Carolina. Junipcrns com- munis, the northern cedar, is known to occur in a few localities in the mountains. The male and female flowers of Junipcrus virginiana are borne on separate trees. The time of flowering is dependent upon the climate and weather. The male trees begin blooming first and the return of cold weather may delay the female trees. In both the seasons 1914 and 1915 the male trees began blooming nearly six weeks before the fe- male trees. The young "berry" is formed soon after pollination by the growth and fusion of the sporophylls about the ovule. Fertilization takes place about the middle of June. The seeds are matured in the first seas- on. The species is very variable in color and habit of growth, varying in the neighborhood of Chapel Hill and Durham, in color from a glaucous to a deep green, and in form from an open spreading tree to a close spreading tree and to a narrow columnar tree. SIGNIFICANCE OF GOSSYPOL IN THE COTTON PLANT F. E. CARRUTH Gossypol, CisHiiOi (or possibly CanH.nOio) according to Marchlew- ski* appears to be a diliydric (ortho) phenol. It occurs in peculiar glands, "resin glands," in all parts of the cotton plant. Its physiological significance is not clear. The change in color of the cotton flower on ageing is probably due to it. It is a yellow substance, dissolving in H3SO4 with a red color and oxidizing easily in alkaline solution with a deep blue color. It is being studied in an endeavor to show that it is a respiration pigment •J. Prakt. Chem. 1899, 60, p. 80. 1915^ Proceedings N. C. Academy of Science 9 or an anthocyanic substance, rather than an end-product of plant metabolism. An effort to elucidate its constitution is being made by the N. C. Experiment Station. FLY-PARASITES AS A FACTOR IN CONTROLLING ARMY- WORM IN NORTH CAROLINA IN 1914 p. SHERMAN The Army-worm (Heliophila unipuncta) was destructive in many localities in North Carolina in 1914, attacking millet, grasses and grains. Tachina-flies were abundant and laid eggs on the worms. A lot of 534 army-worms was separated into groups according to number of eggs per worm, and rearings made. Worms without visible eggs matured less than 10 per cent of moths. Of worms with fly-eggs less than 1 per cent matured moths. Highest development of flies was 'from worms with 3 parasitic eggs each (32.81 per cent), the rate consistently declining both below and above that point. On all worms collected, the average was 2.44 fly-eggs per worm, close to the desired optimum. Outbreaks were of short duration and there was no widespread damage by any later broods. A more detailed article covering this work will be found in Journal of Economic Entomology for April, 1915. ON THE MYTH OF THE SHIP-HOLDER, THE ECHENEIS OR REMORA E. W. GUDGER A brief account was given of some of the data relating to this myth, which began about the time of Pliny the Elder and persisted until about 1660. The true explanation was given by Ekman in 1904 in his work on "dead water." Material and data are being collected for a series of papers giving accounts of and explaining the myth, describing the use of the Remora as a living fish hook, and lastly giving as fully as possible the natural history of the fish — the matter of chief interest being the origin of the sucking disk. THE SEXUALITY OF THE FILAMENT OF SPIROGYRA BERT CUNNINGHAM The general opinion as shown by Wood (1872), Wolle (1887), DeToni, Klebs (1896), Vines, Bennett and Murry, and Mottier (1904), is that the filaments contain cells of one sex. West (1904), basing his assertion upon Hassall (1845), states that cross conjugation is exceed- ingly rare in Conjugales. 10 Journal of the Mitchell Society [July The writer found a Spirogyra which follows the general description of Quadrata, with the exception of reproduction. This frequently oc- cured as cross conjugation, the zygotes being in such a position that it could not possibly be a combination of lateral and scalariform con- jugation. This occurrence would tend to prove that the filaments of some Spirogyra at least are truly bisexual, and that the transition from the bisexual to the unisexual occurred in the family of Spirog3Ta. ABNORMAL SPECIMENS OF TARAXACUM S. W. GEISKR This paper notes the occurrence of a clump of dandelions at a point 70 feet e. n. e. of the n. e. corner of Cox Hall, on the Campus of Guilford College. Seven specimens showed well fasciation of the flower-stipes. The multiple-headed character was not so pronounced as noted by Kirsch (1909:) only two or three stipes in each of the specimens were united. The flower heads were either slightly con- fluent or independent. At the point of collection, the soil was un- usually infertile, and the occurrence suggests Nicuwland's ('09) con- clusion that the abnormality is due to a physiological change due to un- favorable soil conditions, and to age. Bowditch ('09) has also noted fasciation of the dandelion (T. off.) in an unfavorable environment. Diligent search failed to find abnormal specimens outside of the local circumscribed area. For the following papers no abstracts have been received. Tlie Present Status of the Martian Controversy — A. H. Patterson. Filose Phenomena in Pieces of Gonads of a Cubomedusa — H. V. Wilson. More Fossil Plants from the Moncure Shales (32 specimens) — Collier Cbob. Cow Pea Weevil— Z. P. Metcalf. Gossypol, the Toxic Substance of Cottonseed Aleal — \V. A. Withers and F. E. Carruth. The Influence of Salt Solution on the Development of the Frog Egg — W. C. George. Experimental Alteration in the Direction of Growth of a Sponge — H. V. Wilson. The Importance of Humidity in Health and the Arts (with demon- stration of a new form of Humidifier of North Carolina make) — A. H. Patterson. Simplifying our Methods of Teaching Cell Division — Z. P. Metcalf. 1915'] Proceedings ^N". C. Academy of Science 11 Monadnocks and Metamorphism in the Cretaceous Peneplain — Collier Cobb. The Origin of the do, re, mi Syllables for the Musical Scale. — A. H. Patterson. Notes of Geology of Smith's Island — ^Collier Cobb. E. W. GuDGEE, Secretary, AN OUTLINE OF MODERN WORK BEARING ON THE THEORY OF DESCENT BY J. J. WOLFE In my eagerness to select a subject worthy of presentation on this occasion, I have, like many another, attempted a task much bigger than I had realized. It is apparent that nothing approaching encyclopaedic treatment is possible. You will, therefore, find much important work conspicuous by its ab- sence. I do, however, regard the generalizations and experi- ments discussed as being, in the main, those most pertinent to the matter in hand. You can hardly be better persuaded than I am, that it is hazardous in the extreme to attempt to speak at the present time with any degree of positiveness concerning the subsid- iary theories involved. Wide differences exist in the minds of equally able students both as to the value and the inter- pretation to be put upon recent and current work. The subject, however, is so vital, and so grips the attention wherever we meet it, that it seems to me well worth while to review this work even if it nuist be in a most tentative fashion. Mendel's law We may begin this review with the opening of the present century. Until this time the theory of descent was in its essentials just as Darwin had left it in 1859. The year 1900, however, is made memorable by the rediscovery of the unpretentious studies of an Austrian monk, Johann Gregor Mendel. His results were published in 1860 in an obscure journal wlierc they lay buried until unearthed independently and almost simultaneously by three distinguished botanists, Dr. Vries of Holland, Tschermak of Austria and Correns of Germany, ^fendel was a student of Carl Nageli, another great botanist, to whom he sent his results, but somehow the master failed to grasp the significance of his old pupil's work. 19151 Outline on the Theory of Descent 13 Mendel's method differed from that of earlier students of heredity in that he focused his attention upon the behavior of a single pair of alternative characters. He selected the ordinary garden pea to work with, and for eight years car- ried on his experiments in hybridization. The parental characters reappear in their hybrid offspring in a perfectly definite fashion, which has come to be known as '^Mendel's Law." An example or two may make this clear. A tall pea, crossed with a dwarf, produces offspring which are invariably tall. So it is when round seeded pears are crossed with wrinkled ones, yellow with green and with a host of other character-pairs which have been tested by Mendel and his followers. The offspring are not intermediate in character between the two parents as had been universally supposed to be the case, but wholly like one parent which Mendel called the dominant. The character which does not appear in the offspring — dwarfness in this case — is called recessive. IsTow when these hybrids are interbred, three kinds of offspring are produced and, when the numbers are large, in fairly definite proportions. One fourth are dwarfs and breed true. The remaining three-fourths are tall, and look alike, but behave differently in reproduction. One of the fourths is tall and breeds true, the other two-fourths are tall, but not true breeding — they split up again in the same ratio — 25 per cent true breeding tall, 25 per cent true breeding dwarfs, and 50 per cent tall but not breeding true, and re- peating this behavior in the next generation. Another case — the blue Andalusian fowl does not breed true. Its offspring is 25 per cent white, 25 per cent black and 50 per cent blue. The whites and the blacks breed true to color, but the blues repeat the story. The Andalusian is thus seen to be not a true race of fowls but merely a hybrid between a white and a black race, in which black is not en- tirely dominant as it is in guinea pigs for example, and as it usually is, and as tallness is to dwarfness in the case of garden peas. 14 JOUKNAL OF THE MlTCHELL SoCIETY [^July Similar experiments have been carried out involving two and even three pairs of such characters, but the combina- tions become too complex for presentation without figures. Suffice it to say that with but few exceptions any pair of characters will behave as above described. Cases such as those cited show that a character may be extracted in a pure state from a hybrid even when it is completely masked by a dominant. Characters must there- fore be represented in the germ cells by independent units that never lose their identity. Mendelism thus puts in the hands of the experimentalists a definite standard of measurements by means of which he may test the hereditary constitution of living organisms, and to the practical breeder its gives a definite formula in ac- cordance with which he may purge a chosen race of unde- sirable characters and even supplant them with desirable ones extracted from many sources, with somewhat the same exactness that a chemist extracts and combines his chemicals. THE PUKE LINE Before great progress can be made in any science, the fundamental units which enter into its facts must be clearly understood. "Chemistry was alchemy until the chemical elements were identified and isolated.' ' Similar fundamental units in heredity are the Mendelian unit characters, and we now speak of heredity in terms of unit characters rather than of the individual as a whole. A species as the term is today coming to be understood consists of subsidiary groups of individuals, which groups differ from each other in average size, structure, color and other unit characters, which in heredity, according to Jen- nings, behave "as rigid as iron." The progeny of individuals belonging to one such group constitutes the so-called "pure line." This conception rests upon the brilliant and independ- ent investigations of the Danish botanist Johanssen, the American zoologist, Jennings, head of his department at the Johns Hopkins T^niversity, and the Swedish botanist Kilsson. 1915~\ Outline on the Theory of Descent 15 Johanssen, to cite the work of but one of them, experimenting with beans, isohited nineteen such groups of pure lines, " . . . . the progeny of each of these pure lines of beans varied around its own mean, which was different in each of the nineteen instances." It matters not whether the smallest or the largest individuals are chosen to breed from, the progeny in either case is the same, which is the average for the pure line in question. The conclusion then is that ^'Se- lection within a pure line is absolutely without effect in modifying a particular character in the offspring of the line in question." I^or can selection from the mixture of pure lines which constitute the species accomplish more. The utmost that it can do is to isolate that pure line which ex- hibits the character in question developed to the highest de- gree. Manifestly this is a discovery of far-reaching signifi- cance, for if these things be so, how can the transition from one pure line to another have been made ? That such tran- sitions have repeatedly occurred is, it would seem, beyond intelligent question, but how, looms larger today than ever before. There seem to be but two answers now made to this question : one of these is mutation, which makes the passage from one pure line to another at a single bound, but which seems to me much too questionable a support for any great super-structure ; the other is the inheritance of acquired characters, an ancient dogma but not now in good standing in most approved scientific circles. Later on I shall discuss each of these theories at some length, but now before leaving this topic it should be added that Johanssen has recently reported mutations within his pure lines. This is, however, as Walter has pointed out, a clear case of the logician's "vicious circle." For so long as a variation does not reappear in the progeny it is taken to prove that such variations are individual, due to effects of the environment, and not heritable, but, when- ever such variations do reappear, they are at once styled mutations. DARWINISlSr With your indulgence, I will now sketch in as briefly as 16 Journal of the Mitchell Society [July I may the background of Darwinism upon which mutation may be most effectively projected. Darwin, as you well know, based his theory of the origin of species upon the minute variations presented by all living things. There are no two human beings, no two trees, no two flowers, in fact no two living things of any kind exactly alike. Nevertheless, organ- isms continue to produce offspring which in the main re- semble their parents. The developing plant or animal be- haves as if it were acted upon by two opposing forces, one heredity, a centripetal force tending to hold it down to type, the other variation, a centrifugal force tending to throw it off at a tangent. These variations occur in all directions, some of advantage to their possessors, some possibly without effect, othejF positively detrimental. Couple with this the further fact that vastly more plants and animals are produced than can possibly find room and food for development. Tt is difficult to conceive the prodig- ious members of every species that would exist were it not for cheeks put upon them by the environment. The conger- eel it is said lays 15,000,000 eggs. If these all reached ma- turity it has been computed that in less than ten years, the waters of the globe would be solidly full of conger-eels, all the progeny of a single pair. "Even slow-breeding man," says Darwin, ''has doubled in 25 years.'' ''At this rate in less than a thousand years there would literally not be stand- ing room for his progeny." In the keen competition that must thus necessarily ensue in a state of nature the great ma- jority of these are doomed to early destruction. Manifestly it is the best endowed, the fittest in Darwin's phrase who survive. For this process Darwin coined the term natural seJection and looked upon it as the controlling principle in shaping the course of evolution. It operated on those minute variations already referred to, weeding out those individuals which did not vary in directions tending to adapt the organ- ism more perfectly to its environment. The summation of these favorable variations in the course of time would be suffi- 1915~\ Outline on the Theory of Descent 17 cient to warrant classifying the form as a species distinct from the parent type. From the flood of criticism that fell upon the "origin" two ideas may be singled out for consideration. First is the view that imperceptibly small variations in the direction of producing a new structure could be of no possible service and therefore would have no selection-value. Second, that geo- logic time is too short for the evolution of the complex living forms that we know out of simple undifferentiated organisms. Without entering into a discussion of these objections, sufiice it to say that their weight was felt to be great by many Dar- winians. To such, and many others, the mutation theory was most welcome. MUTATION It was ably presented to you at the Wake Forest meeting five years ago by President Poteat. I shall therefore at this time attempt only a brief outline. The mutation theory is the great life-work of Hugo De Vries of Holland already referred to in connection with the rediscovery of Mendel's results. Appearing in 1901 it embodied the extensive ex- perimentation of the preceding twenty years. As a basis for the operation of natural selection, De Vries takes the more striking variations, the previously called "sports" to which he gave the name — mutants — such for example as the sudden appearance of a rose-comb in an apparently pure bred race of single comb fowls, or a white English sparrow, sev- eral times recently reported in "Science," and which I ob- served some months ago on the streets of Durham. Darwin was familiar with this phenomenon and cited numerous cases in his "Animals and Plants under Domestication," but after mature deliberation and after it had been urged upon him by some of his closest scientific friends, he reached the conclusion that "sports" were without important effect on the origin of species — an opinion it would now seem destined to receive recruits. These sports or mutants breed true from the beginning and thus furnish a foundation for the view that new species 18 Journal of the Mitchell Society [July are produced, not as Darwin thonglit by the gradual accumu- lation of minute differences, but all at once bv the sudden ap- pearance of full Hedged new characters which sharply dis- tingiiish them from the parent species. The theory certainly leaped into favor. It cflFectively disposes of the criticisms of Darwin's theory to which I have referred. Furthermore, mutations instead of being extreme- ly rare phenomena are almost becoming common. This is due it would seem to the fact that mutationists are coming to lay less emphasis upon the magnitude of a mutation and more upon its heritability. Many of the departures that now pass as mutations could I think very well be included under Dar- win's variations. To claim heritability as a criterion between mutations and Darwinian variations as seems now to be the tendency would, in my judgment, rob Darwinism of all claim that it has to bring an explanation of evolution, since it leaves it in the absurd position of being based on non-heritable variations. CEITICISM OF MUTATIOX For some years now there has l)een a growing suspicion that the phenomena of mutation are really due to hybridi- zation. The English geneticist, Bateson, seems to have been first to suggest that Lamarck's evening primrose, upon which De Vries primarily based his theory, is in reality a hybrid. Much evidence has now accumulated to sustain this view. Davis, Professor of Botany at Pennsylvania, has attempt- ed l)v hybridization to produce a complex type which in re- production will behave like Oenothera Lamarckiana. He has apparently succeeded in producing fairly constant hybrid races which occasionally throw off mutants much as does the classic example. Similar results have likewise been obtained by Tower working with potato beetles. But in my judgment the most significant attack upon mu- tation has been made by Jeffrey, of the Harvard Botanical laboratory. Jeffrey investigated the evening primroses with a view to determining the amount of sterility present. It has long been known that infertility was characteristic of 1915^ Outline ok the Theory of Descei^t 19 hybrids, and curiously enough this fact was invoked as long ago as 1837 in support of the view that the sperm was really essential to the act of fertilization. In that year R, Wagner showed that sperms were invariably absent in non-fertile hybrids and as invariably present in all fertile males. Jeffrey found that without exception a high degree of sterility was characteristic of every species examined. Furthermore all known hybrid plants available were examined with essen- tially the same result. On the other hand an extensive in- vestigation, ranging from the highest to the lowest plants and including a large number of species as to whose genetic purity no suspicions are entertained, revealed absolutely no sterile pollen whatever. Since in this respect the evening primroses ally themselves with undoubted or suspected hy- brids Jeffrey maintains that the group as a whole is much contaminated by hybridization and that no such important theory as mutation should rest upon so dubious a foundation. De Vries has recently replied at considerable length to Jeff- rey's attack but without, in my judgment, seriously damag- ing the criticism. Among other things, he cites cases of mutation in the com- mon shepherd's purse and asserts that its pollen is all perfect. This, however, is manifestly an error. I have just begun an examination of this plant myself and there is abortive pollen here, just as Jeffrey found in all his hybrids. Since the connection between sterility and hybridization has been so long and so well known, it would seem strange that its significance should have escaped De Vries, who was aware of the fact that sterility was more or less abundant in his primroses. In the controversy which is still going on, it appears that De Vries is inclined to admit the contention of Davis, Tower, Jeffrey and others that mutants may arise as a result of hybridization, but still clings, with other muta- tionists, to the view that mutation is a distinct phenomenon in no way dependent on hybridization. To be sure there are numbers of cases where mutants or sports have appeared in which it is very difficult to impugn 20 Journal of the Mitchell Society [July the purity of the strain, nevertheless in the present state of our knowledge it would seem wiser to account for them as a result of hybridization far back in the line, than as the pro- duction of an entirely new character by the operation of some as yet wholly unknown force. While this would seem to be true it is possible that it does not apply to all cases. De Vries divides his mutants into two classes, one characterized by the appearance of a char- acter wholly new, and the other by the loss of some character previously possessed. This latter, it would seem, might and probably does occur with the intervention of hybridization. It is a matter of common knowledge that accidents happen during the embryonic history of the individual which pre- vent the development of organs and tissues and, to me at any rate, it is no more difficult to think that certain conditions might, even in the germ cells, destroy, some one of these units of living matter which would otherwise in the mature animal express itself as a character. For example, albinos are simply animals in which for some reason or other the color factor has failed to express itself. Granting this, however, the tendency of present investigation is to rob mutation of any really great significance in the hypothesis of descent and perhaps throw us back either to Darwin or Lamarck. ACQUIRED CHARACTERS Whether acquired characters are inherited or not consti- tutes for biologists a seemingly eternal question. Are dis- eases, mutilations, habits, the effects of use and disuse handed on to offspring — these are some of the forms in which the query has been put. But from whatever angle the problem be approached the real aim has been to find whether or not the environment can in any way reach and impress itself upon the germinal substance so that its effects may be transmitted. That such is the case was generally believed a hundred years ago and the idea was made the foundation of the theory of evolution propounded at that time l)v the celebrated French biologist Lamarck. 1915^ Outline on the Theory of Descent 21 There are some more or less well known practices which incidentally seem to support this hypothesis — for example the growing of bacteria under adverse conditions such as ex- cessive heat with a view to reducing their virulence. Certain disease-producing forms so treated may then be safely in- jected into the human being, whereas before such treatment it would have resulted fatally. Southern market gardeners pretty generally purchase northern grown seed where early crops are desired. The explanation is that short northern growing season somehow speeds up the life processes so that the cycle is complete before cold weather. Seed from plants so grown are supposed to inherit this rapid maturity. Tower, a zoologist of Chicago University, in his experi- ments with potato beetles found that species carried from Chicago were so altered by a stay at Tucson, Arizona, under desert conditions that when carried back to Chicago some years later they were unable to withstand the winter. Ac- cording to Tower no selection is practized and this condition is gradually brought about. Bordage, a botanist of Reunion, a French island off the coast of Madagascar, reports that European peaches carried to Reunion retain their deciduous habit permanently at higher altitudes, but in the coastal region the leafless period is gradually shortened until after 20 years they are completely evergreen. Seedlings of such trees show the acquired char- acter to the same extent as the parent tree, but no more. Furthermore they retain this character even to the second generation in higher altitudes where trees that have not been so modified shed their leaves every autumn. Besides such cases there have been many experiments de- vised primarily to prove this proposition. Bonnier, a mem- ber of the French Academy of Sciences, published in 1895 an extensive series of experiments. In all he handled 105 species. Plants growing in the lowlands were transplanted to alpine conditions. In a few years these had acquired the aspect of the characteristic alpine species of the same genus even to cell and tissue structure. When carried back to the 22 JOUEXAL OF THE MiTCIIELL SoCIETY [July lowlands, plants that had grown at elevated locations for four to six years retained their alpine characters for four to six 3^ears, but eventually returned to the habit and character of lowland types. The well known German botanist, Klebs, likewise ex- perimented extensively in this line with the net result that many acquired characters are inherited while others are not. Perhaps experiment should now be directed toward ascertain- ing just what acquired characters are inherited. Lest you should imagine that I have ignored the evidence from the zoological side let me briefly refer to Kammerer's results. It should be added, however, that zoologists are more nearly a unit tlian botanists in the view that acquired char- acters are not inherited. Kammerer at Vienna by reducing the amount of water succeeded in permanently modifying aquatic species of sala- manders so that they came more nearly to resemble land forms and by changing the color of the soil on the bottom of the aquaria transformed the color of the animals so as to correspond very nearly with the color of the substratum. These effects according to Kammerer are hereditary. There are numerous other experiments of this kind made on ani- mals with corresponding results, still it must be said that the bulk of the evidence furnished by experiments on animals seems to support the negative side of this proposition. Un- fortunately, however, this is not a question that can be settled by majorities in the good old democratic way. Castle, of the Harvard Zoological Department, as well as several others, has made some beautiful experiments in the hope of solving the prolilem. Their method consists in graft- ing the ovary of one animal into another from which her o^v^l had ])cen rcinovcd. The body of the animal operated upon may be looked up(m as a new environment for the engrafted ovary, and by reason of the intimate relations existing ought to exercise a marked influence in heredity, if such a thing be possible. The details of one of these experiments is as follows: 1915^ Outline on the Theory of Descent 23 The ovary is removed from a young female, white in color, and that from a black animal substituted. The animal operated upon is then mated with a male pure white in color. All the offspring were absolutely black. The black ovary although transplanted to a white animal produced young which were colored exactly the same as would have been the case had the ovary remained in the body of the black animal from which it was taken. This is in accord with Mendelian principles — black dominating white. In other words the body tissues of the foster-mother had no effect whatever, upon the color of the developing embryo. Castle, as well as others, has regarded such experiments as lending great support to the view that the environment produces no heritable effects. The lifework of August Weisman, the great German biolo- gist and philosopher, who died last fall, was in a sense a continuous and formidable onslaught upon Lamarck's hypo- thesis. Weisman founded his attack upon the fact that the germ substance is very generally early set apart in the de- velopment of each animal from egg to adult. Once so set apart, he contended, the germ cells could not be influenced by the tissue cells, a thing must happen if a character im- pressed upon the body cells is to become hereditary. This has now become to be pretty generally the dominant view with geneticists and embryologists. The Weismannian contention, however, is not so formidable as it once seemed.. It is a well known fact that the germ cells exercise a profound influence on the body cells. Is it too wild a flight to suppose that there might be a reverse influence ? At any rate such a view becomes somewhat more tenable in the light of recent re- searches on the ductless glands, which have their effect in distant parts of the body by means of substances secreted into the blood. These substances are called harmones, and it is coming to believed that they are of very general occurrence and very great importance. The fact upon which Weisman based his criticisms seems to me to furnish a basis for the more or less evident line of cleavage between zoologists and botanists on this question. 24 JOUENAL OF THE MiTCHELL SoCIETY [July The germ-plasm is early set apart in animals, but this is not so in plants which develop new germ tissues each season. Also it would seem more difficult for the environmental in- fluences to penetrate the thicker envelope of body tissues in animals, and to produce effects upon cells in more or less con- stant environment. The body fluids surrounding these cells and which constitute their environment are artificially main- tained at fairly uniform pressure, temperature, composition, and concentration. For these reasons it would seem to be much easier for environmental factors such as temperature, moisture, and light, to act upon the germ tissues of plants than of animals. However this may be, it is much more than probable that any generalization such as the inheritance of acquired characters if found to be true for plants would also be true for animals, although it is easily conceivable that special animal characteristics might render the operation more difficult of observation. Such a view appears at least to be near the truth. The inheritance of environmental effects in some fashion has long seemed to me a logical necessity. To assume that they are not, would force the conclusion that all heritable variations are represented in the germ-plasm, and, to carry the thing to its ultimate end, there were l)undled up in the first organism all the infinity of possibilities that have since appeared in living things. Darwin, in liis later wi'itings, felt that the en- vironment in some way acted upon the germ cells so as to call forth variation, lait the cause of most variation was so dark tliat lie fi-c