8 H. L. WIEMAN 



the lctt(M's I) ;iii(l il to (Ictiotf the lar,n('i' and smaller allosome respectively, 

 ill so (loinjj; we should recall that each allosoiiie divides only once in 

 the course of tlie two maturation mitoses, and undergoes one trans- 

 port (reductional) without division. 



Condition A, 59 caseft. Both D and d at one spindle pole (of the 

 first spermatocyte). Both would then go to one secondary spermato- 

 cyte and in that o)ie divide equationally. 118 spermatids would then 

 each contain \ D and ] d, while 118 would receive no part of these. 

 This is the most usual condition and the one discovered by Guyer. 



Condition B, 5 cases. D at one spindle pole and d at the opposite 

 pole. One secondary spermatocyte would receive D entire, and the 

 other d entire. These dividing in the secondary spermatocytes would 

 result in 10 spermatids each with | D and 10 each with h d. 



Condition C, 10 cases. D at one spindle pole, | d at that pole and 

 I d at the opposite pole. Half the secondary spermatocytes would 

 receive only h d, which does not divide again, consetjuently from this 

 line would result 10 sjiermatids with h d and 10 with no allosome. The 

 remaining secondary spermatocytes would receive D and | d; the 

 former would divide in them but not in the latter, and there would re- 

 sult 10 spermatids with ^ D and 10 with h D and | d. 



Condition D, 5 cases. D probably dividing at the equator (for it is 

 absent at the poles), d at one spindle pole. Half the secondary sper- 

 matocytes would receive d and h D; in them d would divide but not | D, 

 and there would be formed 5 spermatids with \ d, and 5 with ^ d and | D. 

 The other secondary spermatocytes would receive only ^ D, which 

 would not divide in them, consequently 5 spermatids would receive 

 ^ D and 5 would receive none. 



Condition E, 3 cases. Both D and d dividing in the equator. Every 

 secondary spermatocyte would then receive ^ D and | d, and these 

 would not divide again. It would then be a matter of chance how 

 these allosonies became distributed to the spermatids. There might 

 be: either 6 spermatids with | D and 6 with | d; or 6 spermatids with 

 ^ D and | d, and 6 spermatids with no allosomes. . . . That is 

 (omitting condition E) 42.09 per cent of the spermatids contain 2 allo- 

 somes, the same number contain no allosomes, and 15.82 per cent 

 contain one allosome. 



There are then in man certainly four classes of spermatozoa with 

 regard to their allosome content, and possibly five or six. Scarcely 

 any of the spermatozoa examined show abnormalities and no degenerat- 

 ing ones were found, therefore there is no reason to believe that all 

 but certain classes of sperm degenerate or prove incapable of fertiliza- 

 tion (p. 9 and 10). 



Concerning another point Montgomery says (p. 12), 



Bardeleben held that a second reduction occurs in the secondary 

 spermatocytes resulting in approximately a quarter of the normal num- 

 ber in the spermatoids. Guyer found about the same result, conclud- 

 ing of the secondary spermatocytes that "half of them show five and 



