572 FERNANDUS PAYNE 



Specimen 3/f.-2 is the most puzzling individual of them all. 

 The chromosome distrubution is somewhat different from the 

 others and this leads me to suspect that it may be a different 

 species. The most striking variations are in the spermatogonial 

 divisions. Two different cysts were found in division and varia- 

 tions were present in both. Among 33 counts of clear metaphase 

 plates there were nine with 24 chromosomes, 16 with 25, seven 

 with 26 and one with 27; (for these variations see fig. 6, ^, 27; 

 B, C, D, 26; E, F, G, H, 25 and /, /, 24 chromosomes). I am at a 

 loss to explain these variations and certainly will not draw any 

 conclusions from them. However, a few suggestions which the 

 facts warrant may not be out of place. As there are a number of 

 multipolar figures in the cyst, it is possible that these divisions 

 may be pathological. Secondly it is possible that the chro- 

 mosomes which behave irregularly in the spermatocyte divisions 

 may also behave irregularly in the spermatogonial divisions. 

 Thirdly, all counts (45) of the first spermatocyte division with the 

 exception of one — and as we shall see this is really not an ex- 

 ception — show 13 chromosomes. Twelve of these 13 are bi- 

 valent and one single (fig. 6, L, M, N, three metaphase plates 

 which have been smashed to cause the chromosomes to lie flat 

 as in a smear preparation). Figure 7, A, B, C, are serial sections 

 of a single cell, showing likewise 12 bivalent and one univalent 

 chromosome. In case there are 14 present, 11 are bivalent and 

 three univalent (fig. 7, E and F) . So, as in the case of the other 

 individuals, the two groups are in reality the same, although 

 they appear different in polar views. The chromosomes then 

 in the first division must have come from a spermatogonial 

 cell with 25 chromosomes, 24 of them uniting two by two to form 



Fig. 6 Specimen 34-2. A, spermatogonial group with 27 chromosomes; 

 B, C, D, the same with 26 chromosomes ; E, F, G, H, the same with 25 chromosomes ; 

 /, J, the same with 24 chromosomes; K, growth period showing nucleoli; L, M, N, 

 first maturation divisions, metaphase, which have been smashed as in a .smear 

 preparation, showing 13 chromosomes, 12 of which are bivalent and one univalent; 

 O, first division, polar view, 14 chromosomes; P, first division, 13 chromosomes 

 (0 and P are found in the same cyst) ; Q, R, anaphases, polar view, from the same 

 spindle; Q, 13 chromosomes and R, 12; .S, T, second spermatocyte divisions showing 

 13 and 12 chromosomes respectively. 



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