194 



ROBERT H. BO WEN. 



If this suggestion be correct, in tripolar spindles the dictyosomes 

 should obviously be arranged around each spindle pole (centriole ) 

 in a manner similar to that found in bipolar figures. This, is, in 

 fact, the case as the figures show very clearly (Figs, i and 2), 

 and seems to contribute additional evidence to that already ac- 

 cumulated tending to demonstrate an element of unusual regu- 

 larity in the distribution of the Golgi apparatus in cell division. 



DISCUSSION. 



Abnormal mitoses in the male germ cell cycle are chiefly of 

 interest from the standpoint of the sperms which might be pro- 

 duced as a result of such divisions. It is clear that the sperms 

 derived from divisions belonging to Case i would always be 

 abnormal; and those of Case j (if the division were ever com- 

 pleted, which seems doubtful 1 ) would likewise be abnormal in 

 the great majority of cases. Whether any such abnormal sperms 

 ever take part in successful fertilization is questionable. After 

 divisions of the Case 2 variety, however, there is no reason for 

 supposing that the resultant sperms might not behave in an en- 

 tirely normal manner in fertilization. This is particularly true 

 of the case which I have described in Euschistus, and to the pos- 

 sibilities there presented I should like to give particular attention. 



It is evident that tetraploid spermatogonia would probably give 

 rise to diploid primary spermatocytes, and this probability has 

 been definitely proved in the EuscJiistiis case. It seems equally 

 probable that the resultant sperms would likewise contain a group 

 of chromosomes in the diploid rather than the normal, haploid 

 number. Unfortunately definite proof of this has not been ob- 

 tainable, but everything indicates that such is actually the case. 

 If such diploid sperms should fertilize a normal (haploid) egg, 

 a triploid individual would result ; and if, as an almost impossibly 

 rare coincidence, the egg should also be diploid, through some 

 abnormality, a tetraploid individual would result. The triploid 

 individuals might be numerous due to the involvement of a large 

 number of sperms, but they would be accompanied by diploid in- 

 dividuals derived through some of the normal, haploid sperms 



1 It is perhaps more probable that these abnormal mitoses fail, giving rise 

 to the familiar giant spermatids with one large nucleus but a multiple set 

 of centrioles. 



