No. 1, July, 1920] GENETICS 83 



teetli and bred to pure-bred cows, produced in 2 successive ye its 5 c ilvea vritb deficient coats, 

 3 of which are known to have defective dentation corresponding to the Bire. Since the hull 

 was not born on the place and all of the calves including !•"> to20 normal ones were all reared 

 under similar conditions it is probable thai the cause is genetic rather than physiological. — 

 Maxwell J. Dorsey. 



."17. Conklin, Edwin Grant. Heredity and environment in the development of men. Srd 

 ed., 15X21 cm., v + 311 p., 101 fig. Princeton University Press: Princeton, N. J. 1919. 

 — Present edition like previous ones is divided into six chapters. (1) Facts and factors of 

 development. Includes detailed treatment of development of body and mind and discussion 

 of theories of development. Emphasis is placed on essential unity of organisms; intrinsic 

 (hereditary) and extrinsic (environmental) factors of development are discussed. (2) Phe- 

 nomena of inheritance. Observations on inheritance are described and statistical and ex- 

 perimental methods of study are compared. List of human characters which Mendelize is 

 given. Doctrine of universality of Mendelian principles is supported. (3) Cellular basis of 

 heredity. Includes account of germ-cell formation and behavior in fertilization, sex-deter- 

 mination, mechanism of heredity and of development. Specific roles of chromatin and cyto- 

 plasm in heredity and development are contrasted. (4) Influence of environment. Includes 

 discussion of relative importance of heredity and environment and account of experimental 

 modification of development. (5) Control of heredity; eugenics. Methods of breeding 

 employed in establishment of domesticated races of animals and plants are described and 

 control of human heredity is discussed. (6) Genetics and ethics. Voluntaristic conception 

 of nature and of human responsibility, mechanistic conception of nature and of personality, 

 determinism and responsibility, the individual and the race, are topics discussed. Poten- 

 tialities of development are contrasted with actualities; heredity is regarded as determining a 

 limit, closeness of approach to which depends upon factors of development. List of larger 

 references, glossary, and index complete the book. Subject material and illustrations are 

 carefully selected; animal side is emphasized, but plant side is not neglected; each phase of 

 the subject is developed logically; historical allusions are skillfully interwoven in the text; 

 and biological principles are related in a scholarly manner to the great body of human 

 thought. — Present edition differs from second only in minor changes in text and figures, except 

 in third chapter which has been rearranged and revised in order to give proper weight to results 

 of Drosophila investigations. Among other changes are introduction of more numerous chap- 

 ter headings, exchange of places of second and third chapters, and reduction in number of 

 pages (from 550 in second edition), which has been accomplished by use of smaller type. 

 Subject material has been very slightly augmented, number of figures has been increased 

 from 96 to 101.— R. E. Clausen. 



518. Conklin, E. G. The mechanism of evolution in the light of heredity and develop- 

 ment. Sci. Monthly 9: 481-505. 1919. Ibid. 10: 52-62. Fig. 1-10. 1920.— The illustrations 

 are all zoological. — The paper discusses the experimental and analytical studies of inherit- 

 ance and development in their relation to evolution. — L. Pace. 



9. Cook, O. F. Olneya beans. Jour. Heredity 10:321-331. Fig. 13-17. 1919.— A 

 discussion of the economic and genetic possibilities of Olynea iesola, a southwestern desert 

 leguminous tree. The wood is heavy and hard, the beans edible and the tree hardy. There 

 are many possibilities in selection both for bean production and as a wood plant for the 

 desert. — Maxwell J. Dorsey. 



550. Correns, C. Vererbungsversuche mit buntblattrigen Sippen. II. Vier neue Typen 

 bunter Periklinalchimaren. [Genetical studies with variegated races. II. Four new types of 

 variegated periclinal chimeras.] Sitzungsber. K. Akad. Wiss. 44: 820-S57. 1919. — The four new 

 types of periclinal chimeras described are, leucodermis (found in Arabis, Aubretia)] ps ndo- 

 codermis (found in Arabis, Glechoma) : chl mis (found in Arabis) ; and albopclliculatus 



(found in Mesembryanthemum). They are compared with Baur's 'albot urticatus' type found in 

 Pelargonium. — All four types arc anatomically alike. Leucodermis, pseudoleucodermis and albo- 



