Further Studies on Reproduction in Sagitta. 297 



are heavier and more lasting than the surrounding network (Fig. 

 75). Fig. 76 is from an older egg, where the netw^ork has nearly 

 all disappeared and the central figures are spread out thinner. 

 In Sagitta decipiens (Fig. 77 and 78) we find the irregular figures 

 without the network. 



As the above described intranuclear network is evidently de- 

 rived from the large chromatin-like masses and granules of the 

 younger oocytes, and these masses and granules are either de- 

 veloped under the influence of the chromosomes, or, more prob- 

 ably, are material extruded from the chromosomes of the early- 

 growth stage, I think we must regard it as comparable to the 

 chromatin-like material frequently given off from the chromo- 

 somes in early growth stages of both spermatocytes and oocytes 

 (see Boring, '07, Figs. 62-67, and King, '08, Figs. 26-30), and not 

 to the mitochondria which is found outside the nucleus, usually 

 in the form of fibers, and which has not been satisfactorily traced 

 to a nuclear origin. Ordinarily when one sees such material 

 thrown out by the chromosomes or spireme, one is inclined to 

 regard it as waste material, but the case of Sagitta, where the 

 material forms such a conspicuous pattern on the nuclear mem- 

 brane during the greater part of the growth stage of the oocyte, 

 strengthens the growing opinion that such material may have a 

 specific function in connection with the growth-process of the 

 egg. So far as I can see, there is no evidence whatever that either 

 the chromatin-like masses seen against the nuclear membrane 

 in spermatogonia, oogonia, and young oocytes, or the elaborate 

 pattern of older oocytes, can possibly be derived from Elpatiews- 

 ky's ' besondere Korper ' or from the degenerate inner connecting, 

 or fertilization cell of the ovum, as Buchner ('10) has suggested. 



Synapsis and Spermatogenesis 



In regard to synapsis, I have no new evidence to add to that 

 given in my two earlier papers. I have found nothing opposed 

 to the conclusion that in Sagitta we have a case of parasynapsis 

 in the oocyte and telosynapsis in the spermatocyte. Synizesis 

 and bouquet stages (Figs. 79-81) are not uncommon among the 



