THE BEHAVIOR OF THE ACCESSORY CHROMOSOMES 



AND OF THE CHROMATOID BODY IN THE 



SPERMATOGENESIS OF THE RABBIT. 1 



L. J. BACHHUBER, 

 UNIVERSITY OF WISCONSIN, DEPARTMENT OF EXPERIMENTAL BREEDING. 



The following studies resulted from a series of experiments 

 to determine the effect of lead poisoning upon the germ-cells 

 of the male rabbit as indicated by his offspring. My intention 

 originally was to attempt to determine the manner in which the 

 lead-poisoning affected the normal mitosis. The problem of the 

 normal mitosis in itself proved to be so large that the study of 

 the effect of lead-poisoning had to be postponed to a future time. 



The following work was done under the direction of Dr. M. F. 

 Guyer, to whom the writer is very much indebted for many 

 valuable criticisms and kindly help. The writer is also indebted 

 to the kindness of Professor L. J. Cole for aid given in getting the 

 necessary material for this study. 



All of the rabbit testes used were from animals raised at the 

 barns of the Department of Experimental Breeding of the 

 University of Wisconsin. These males were chosen from the 

 normal stock resulting from the double matings described by 

 Cole and Bachhuber (1914). 



A fairly successful fixing reagent was found in Flemming's 

 strong. This method brought out the chromosomal and cyto- 

 plasmic structures better than Gilson's, Zenker's, Hermann's 

 and possibly Bouin's fixative. Bouin's gave good results in the 

 study of the accessory chromosomes and the chromatoid body. 

 A new method reported to be in use in McClung's laboratory 

 was also tried with considerable success. This fixative employs 

 urea as a means of more rapid penetration. To one hundred 

 cubic centimeters of Bouin's, made up of seventy-five parts of 



1 Papers from the Department of Experimental Breeding, Wisconsin Agricultural 

 Experiment Station, No. 6. Published with the approval of the Director of the 

 Station. 



294 



