MARK AND COPELAND. — SPERMATOGENESIS OF THE HONEY BEE. 109 



terminal part, containing the chromatin, is detached in the form of a 

 very small cell, — much smaller, indeed, than the interzonal body pre- 

 viously set free. We have called this a cell, though it is difficult to 

 determine how much, if any, undifferentiated cytoplasm is cut off with 

 the nuclear matter. This, however, is a difficulty which is often en- 

 countered in studying the polar cells formed during the maturation of 

 eggs, and does not in our opinion preclude the use of this designation. 

 When fully separated from its sister cell, this small cell assumes a 

 spherical form and increases in size. The nucleus of the larger cell, 

 the spermatid, likewise increases in size and becomes to all appear- 

 ances the counterpart of the detached polar cell. Figure 15 represents 

 the two cells at this stage, and it also shows the previously eliminated 

 interzonal body, now much diminished in size. The chromatin in 

 both nuclear bodies becomes variously aggregated, but assumes in 

 general a peripl 3ral position ; the metamorphosis of the larger cell 

 — the spermatid — now begins. 



Meves in his description of the first "Richtungskorper" is evidently 

 dealing with what we have called the interzonal body, the peculiar 

 history of which has been briefly described. If this so-called bud 

 were in truth made up simply of undifferentiated cytoplasm, as Meves 

 leads us to believe, perhaps one would be justified in considering it a 

 rudimentary spermatocyte of the second order, even though it con- 

 tained no chromatin. But if it is composed of the remnants of the 

 interzonal filaments, which have become metamorphosed into a definite 

 body within the cell, and is surrounded by only the slightest amount 

 of undifferentiated cytoplasm, if any, it is difficult to find any sufficient 

 basis for homologizing it with the first spermatocyte division of typical 

 spermatogenesis. Moreover, such a casting forth of spermatogonial 

 spindle remnants has already been observed in cases where four 

 functional spermatids are formed in the normal way, and where, conse- 

 quently, this elimination of interzonal matter can have nothing to 

 do with the first spermatocyte division. Paulmier ('98, p. 228) has 

 described such conditions in Anasa tristis in the following terms : " At 

 the tip of the resting cell [spermatogonium] is a structureless mass 

 which is formed from the remains of the intermediate spindle fibres 

 [interzonal filaments] of the preceding division." Further on he adds, 

 " As a group of chromosomes approaches the end of its movement the 

 cell loses its conical shape and becomes more cylindrical, and the 

 Zell-Koppel [interzonal body] of the preceding generation is cast 

 off, remaining for a time as a small isolated mass, which ultimately 

 disappears." Blackman (■• 05, p. 37) likewise describes a somewhat 



