CHAPTER XIX 



The Chromosome Mechanism of Heredity in Relation 

 to Dairy Cattle Inheritance 



The cytology of the germ cells of cattle has been worked out by 

 Wodsedalek and Masui. These papers may be read and discussed. 

 Problems showing the probable distribution of the sex chromosomes 

 and the proportion of chromosomes received by the offspring from 

 certain of their grandparents may be worked. This information should 

 then be considered from the view point of the inheritance of milk 

 yield and butter-fat percentage. If it is possible to obtain slides 

 of cattle test is or ovary from the Biology department of the Uni- 

 versity, the student will find it interesting to study them in the 

 attempt to obtain the number of chromosomes and the manner in 

 which they divide. Do not get discouraged if the first slides are 

 not good for the material is difficult to fix properly; obtain fresh 

 material and try fixing it again. 



REFERENCES 



MasuIj Kiyoshi. 1919. The spermatogenesis of domestic mammals II. The 



spermatogenesis of cattle (Bos taurus) . Jour. Coll. Agr. Tokyo 



Imperial Univ. 3: 277-403. 

 Wodsedalek, J. E. 1920. Studies on the cells of cattle with special reference 



to the spermatogenesis, oogonia, and sex-determination, Biol. Bui., 



vol. 38, pp. 290-317. 

 See also M. S„ Chapter XXIX. 



105 



