271 



mena can be accounted for in thiswise, although De St. -Joseph 

 has observed the formation of a stolon anterior to the 14th segment 

 in A. lo7igicii'ris . As, however, one of my specimens bore sperm 

 cells in a stage of development equal to the sperm cells found in re- 

 cently separated free-swimming individuals, and as there was no ex- 

 ternal or internal evidence of bud formation , ftfter such a stage of 

 advancement it is not likely that the formation of a stolon would take 

 place later on. 



The conversion of a parent stock into a sexual individual (called 

 Epitokie by Ehlers, Epigamie by Claparède and Malaquin) has 

 been observed in A. longiferieus by Malaquin (Recherches sur les 

 Syllidiens) and has been demonstrated in several other Syllideans by a 

 few investigators. In such cases the parent stock acquires the identi- 

 cal characteristics peculiar to the sexual individual. In my specimens 

 of A. ornatus I have been able to observe no well marked changes in 

 their external appearances , and with the exception of a very slight 

 difference in the size of the eyes the ovule or sperm -bearing indivi- 

 duals do not differ externally from those devoid of sexual products. 

 Since, moreover, these phenomena make their appearance in the sto- 

 lon just prior to its separation from the parent stock, it is likely that 

 my specimens may have been too young to show such changes. With 

 the exception of slight changes of doubtful significance the internal 

 differences I was able to observe were no more than such as Avould 

 naturally result in the displacement of the alimentary canal by an ac- 

 cumulation of ovules and sperm cells in the body cavity. 



While my material would hardly justify the assertion that in this 

 species there is a conversion of a parent stock into a sexual individual, 

 nevertheless, these phenomena, I think, strongly suggest such a con- 

 dition. 



The complete verification of these phenomena in the parent stock 

 of A. ornatus would indicate a different aspect to alternate generation 

 at least in this species of Autolytus. 



Ursinus College, Collegeville, Pa., U.S.A., April 6, 1896. 



7. Vorläufige Mittheilung über die Entwicklung des Seesternes 

 Asterias pallidal 



Von Seïtaro Goto, Zoöl. Lab., Mus. Comp. Zoöl., Cambridge, Mass., U.S.A. 



eingeg. 23. April 1896. 



In dieser vorläufigen Mittheilung beabsichtige ich die Haupt- 

 resultate der vergangenen Winters im hiesigen Laboratorium unter 



1 Contributions from the Zoological Laboratory of the Museum of Compara- 

 tive Zoology at Harvard College, under the direction of E. L. Mark , No. LXI. 



