Hyatt.] 60 [March 5, 



spermatozoa wholly from the division of the nucleus, and does not 

 admit the presence of a protoplasmic residuum in the cyst of 

 Porifera. Polae Jeff's remarks seem very clear and specific but 

 there is great room for error in such observations and they need 

 confirmation, since they are opposed to the general results of La 

 Valette St. George and others. Certainly one matured cyst with 

 fully formed spermatozoa, which we have seen, contained two 

 round bodies, apparantly masses of protoplasm, and several times 

 larger than the fully grown active spermatozoa, which lined the 

 cyst. The two cell-like bodies occured on one side and in the lower 

 part of the cyst, which was surrounded by a special envelope hav- 

 ing a round opening at the top, similar to the micropyle in the 

 chorion of the ovum. This body could not have been an ampul- 

 laceous sac, since it was as large as a larval form found in the 

 same colony ; and the wriggling motion of the spermatozoa with 

 their heads against the envelope, forming a layer of closely 

 set rounded granules, left no room for the supposition that they 

 were parasites. It was found with one other specimen in 

 Chalinula limbata at Eastport. 



Dr. T. Eimer (Arch. Micr. Anat. 1872, vol. vm, p. 290), in his 

 article on the development of the Spermatozoa among sponges, 

 states that the results of his researches confirm the opinion that 

 these arise from the nucleus, " und zwar scheint der Kopf aus 

 dem Kern sich zu bilden, wahrend der Faden aus dem Proto- 

 plasma der Zelle entsteht." Schultze's figure of the spermatocyst 

 of Halisarca lobularis gives the cells of the chorion or cyst clearly 

 (Zeitschr. Wiss. Zool. vol. xxviii, pi. 3, f. 18.). In Aplysilla sulfurea 

 (ibid, vol. xxx, pi. 23, f. 20), several spermatocysts in different 

 stages are represented, and in separate figures, the spermatozoa 

 (pi. 24 f. 28) exhibit distinct nuclei, one dark refractile and the 

 other lighter colored near the tail. Spongelia pallescens ( ibid vol. 

 xxxii, pi. 8, f. 12), Hircinia spinulosa (ibid, vol. xxxm, pi. 3, f. 4), 

 and all of the above exhibit no signs of protoplasmic residuum, and 

 appear to confirm Polaejeff's conclusion that there is no cysten- 

 kern in the cyst. Schultze, however, did not see the early stages 

 or search for a residual mass and this leaves the evidence in an 

 incomplete condition. Polaejeff in Rep. on Calcarea, reiterates 

 his conclusions, and tries to show, that the spermatocyst in Cal- 

 carea has a peculiar covering different from that demonstrated 



