No. 2, September, 1920) GENETICS 219 



1660. Stein, E. [German rev. of: van Hkkui.km:-., M. A. De invloed van radium- 

 stralen op de ontwikkeling der eieren van Daphnia pulex. (Effects of the rays of radium on the 

 oogenesis of Daphnia pulex.) Genetics 1: 305-320. July, 1919. (See Bot. Absts. 3, Entry 

 1044.)] Zeitschr. indukt. Abstamm. Vererb. 22: 286-287. May, 1920. 



1661. Steinach, E. Histologische Beschaffenheit der Keimdruse bei homosexuellen 

 Mannern. [Histological condition of the gonads in homosexual men.] Arch. Entwicklungs- 

 mcch. Organ. 46: ::!) :;?. PI. 3-5. 1920.— Interstitial cells characteristic of the ovary were 

 found in the testes of several homosexual men, associated with degeneration of male inter- 

 stitial cells, and of the seminal tubules. As reported elsewhere (Steinach und Lichten- 

 stebn, Munch, med. Wochensch. Nr. 6, 1918), these testes were removed and cryptorchid 

 testes with normal puberty gland implanted, restoring normal sexual instincts to the homo- 

 sexuals. — H. D. Goodale. 



1662. Steinach, E. Kiinstliche und natiirliche Zwitterdriisen und ihre analogen Wirk- 

 ungen. [Artificial and natural hermaphroditic glands and their analogous functioning.] Arch. 

 Entwicklungsmech. Organ. 46 : 12-28. 1920. — A discussion of castration, feminization, mascu- 

 linization, and hermaphroditization, some of it based on work previously unpublished, with 

 particular reference to the similarity between homosexuals and certain artificial hermaphro- 

 dites. Two instances of homosexual goats are described. — H. D. Goodale. 



1663. Stockard, Charles R., and G. N. Papanicolaou. Variations of structural 

 expression in the inheritance of Polydactyly. Anat. Rec. 18 : 262-263. April 20, 1920. — Author's 

 abstract of paper read before American Association of Anatomists, April 1-3, 1920. — The 

 inheritance of Polydactyly in a strain of guinea-pigs has been studied for the past several years. 

 This character when it appears in the race is inherited as a Mendelian dominant. — The expres- 

 sion of the character in a series of individuals presents a most striking condition. The extra 

 toe on the hind foot may be a perfectly developed functional toe in one animal, while in others 

 the toe presents varying degrees of imperfect development and structure until in some it is 

 represented by only a minute toe-nail attached to the foot by a thread-like filament. This 

 poorly formed toe is frequently broken off or lost shortly after birth, and would often escape 

 notice if not carefully looked for. Other animals inherit the extra toe, but fail to develop 

 it sufficiently to show any evidence of its existence at birth. The fact that these have the 

 character for extra toes is demonstrated by their offspring which may exhibit the toe as 

 frequently as do offspring from parents with well-expressed Polydactyly. — These normal 

 variations in the expression of this dominant character renders it a most uncertain quantity 

 for judging the influences of experimental treatments on its inheritable behavior in different 

 groups of animals. — Charles R. Stockard and G. N. Papanicolaou. 



1664. Stomps, Theo. J. Uber zwei Typen von Weissrandbunt bei Oenothera biennis L. 

 [On two types of white margins in Oenothera biennis L.] Zeitschr. indukt. Abstamm. Vererb. 

 22:261-274. May, 1920. 



1665. Stout, A. B. The aims and methods of plant breeding. Jour. New York Bot. Gard. 

 21: 1-16. Jan., 1920. — Author notes rise of subject during past three decades which has cul- 

 minated in the present day development of genetics. Broadly considered, plant breeding, 

 through selection of seed parents, is older than written history, but modern methods of plant 

 breeding are based on a knowledge of sexuality in plants. Notes work of early investigators 

 in study of sexuality, hybridization and selection including the early pedigree methods of 

 Le Cotjteur and Shirreff, also the early work on sugar beets. — Importance of hybridization 

 as a means of inducing variation is noted. Also development and importance of chromosome 

 theory of inheritance and Mendel's Law. The rise of the mutation theory, linkage, multiple 

 and modifying factors is also noted. Author notes "the germ plasm is the seat in which most 

 of the hereditary changes occur." Cites the case of the 6,500 varieties of Dahlia in cultiva- 

 tion in the United States, all of which have descended from a single American species during 

 the past 130 years. Similarly with Phlox, 200 varieties of which have descended from a single 



