ANIMAL PKODUCTION. 371 



contains data on the length, breadth, and thickness of the walls ot the cannon 

 bone in horses. The bones were also examined chemically and. microscopically. 



A bibliography is appended. 



The problem of the origin of species and recent theories of heredity, E. 

 HiRS (Schwciz. Arch. Tierheilk., 53 {1011), Nos. 1, pp. 14-27; 2, pp. 71-83).— A 

 summary of recent work on heredity and the evolution of species. 



The law of the origin of the sex and the means by which the sex of the 

 individual is influenced, I. Sutkowsky {Berlin. Klinik, 1909, No. 252, pp. 

 l-'n; abs. in Arch. AV/s.se/i, u. acscU. Biol, 7 {1010), A'o. 2, pp. 2-'{l, 242).— 

 Various theories on this subject are reviewed and a new theory proposed, based 

 on the belief that the sex of the embryo is dependent upon the chemical reac- 

 tion of the medium through which the spermatozoon passes on its way to the 

 egg, as it is very sensitive to change, losing its motility in acids and regaining 

 it in alkalis. It is also claimed that an acid medium causes a production of 

 females and an alkaline medium the production of males. 



Kineniatography of fertilization and cell division, G. J. Ries {Arch. 

 Mikro.s. Aiuit. u. Entuicklunfj.'iycschichtc, 7// {1009), Xo. 1, pp. 1-31, pis. 2, figs. 

 12). — This contains information on the use of the kinematograph, by means of 

 which a continuous picture can be obtained of all stages and changes in the 

 siiermatozoa, unfertilized egg, cell division, and the early stages of development 

 of the fertilized eggs. 



On the influence of the spermatozoa on the uterus, J. H. F. Kohlbrugge 

 {Ztschr. Morph. u. Anthropol., 12 {1909), No. 2, pp. 359-368, figs. 2; abs. in 

 Arch. Rasscn u. Gesell. Biol., 7 {1910), No. 2, pp. 250, 251). — ^The sex organs of 

 1,300 Javan bats wore examined and large numbers of spermatozoa were found 

 in the epithelium of the uterus and in adjoining tissues. The author thinks 

 that the penetration of millions of spermatozoa into the mucosa uteri of great 

 importance, as it may produce an effect similar to that caused by injections of 

 serum, with the possibility that the biochemic changes of the uterine tissues in 

 turn may affect the growing embryo, in which case somatic changes of the 

 embryo would furnish a demonstration of telegony though not necessarily the 

 inheritance of acquired characters. 



The influence of the spermatozoa on the blastula, J. H. F. Kohlbrugge 

 {Arch, llikros. Anat. u. Entioicklungsgcschichte, 75 {1010), No. 3, pp. 519-521, 

 fig. 1; abs. in Zcntbl. Allg. u. Expt. Biol., 1 {1010), No. 9-10, p. 337).— Addi- 

 tional experiments on the bat showed that the spermatozoa penetrated the 

 blastula and the embryonic disk after the zona pellucida was ruptured. The 

 author suggests that the sperm entered the developing ova from 8 to 10 days 

 after fertilization, and thus the male may have influenced the embryo apart 

 from amphimixis. 



Experimental contributions on abortion and sterility induced by Roent- 

 g'en rays, F. Trillmicii {Experimcnteller Bcitrag 'zur Einleitung dcs kiinst- 

 lichcn Abortus tind zur Sterilisation (lurch Rontgcnstruhlcn. Inaug. Diss., Univ. 

 Freiburg, 1910, pp. 62; abs. in Zcntbl. Gesam. Physiol, u. Path. Stoffwcchsels, 

 n. ser., 6 {1011), No. 8, p. 352). — Exposure to Roentgen rays caused abortion 

 and sterility in a large percentage of the guinea pigs so treated. 



A note on zebra hybrid breeding-, E. H. Riley {TJ. S. Dept. Agr., Bur. 

 Anim. Indus. Rpt. 1900, pp. 220-232, pis. 3). — A summary is given of previous 

 attempts by various investigators to obtain zebra hybrids, and a brief report is 

 made of the zebra hybrids which have been obtained at the Bureau experiment 

 station, the data presented being substantially those previously noted from 

 another source (E. S. R., 23, p. 671). 



Miscellaneous information concerning the live stock industry, J. Roberts 

 {U. -S'. Dept. Agr., Bur. Anim. Indus. Rpt. 1909, pp. 30i-342).— This is the usual 



4496°— Xo. 4—11 6 



