THE BODY -CAVITIES OF THE STAR-FISH. 



By 8EITARO GOTO. 



First High Sclool, Tokyo. 



In a paper on the metamorphosis of Asteria* pallida (1) published a short 

 while ago I have come to conclusions, which are in several respects contradictory 

 to those arrived at by others from a study of other species. In particular, my 

 results, while confirming those of MicBride (2) in many essential points, could not 

 at the same time be reconciled with them in several not unimportant details. To 

 see if these differences are to be explained by the principle of personal equation 

 or are really due to differences of species I obtained some material of Aslerina 

 gibbosa from the Zoological Station of Naples and have made a close comparison 

 with the species formerly studied by me. The result was that, while the embry- 

 ological differences of the two species are not so great as might be inferred from a 

 comparison of the published accounts, yet are in some respects decidedly conspicu- 

 ous. 



The enteroccel of an adult star-fish consists, aside from the axial sinus and 

 some other smaller cavities, of two compartments entirely separated from each 

 other by a continuous and somewhat complicated mesentery, one lying on the 

 aboral side of the gut and the other mostly on the oral side. The former I have 

 called the epigastric enteroccel, and the latter may be called the hypogastric entero- 

 ccel. In this paper [ shall, in the first place, describe the relation of these two 

 cavities to the larval body-cavities in Asteri-na gibbosa and compare it with what 

 obtains in Asterias, and then treat of some of those accessory cavities above refer- 

 red to ; confining our attention to general features and reserving the details for 

 another paper accompanied by plate, to be shortly published in the Journal of 

 the College of Science, Imperial University of Tokyo. 



The various enterccelic cavities that arise during development and their 

 genetic relations to the four portions of the larval entercœl in As'nias pallida may 

 be diagrammatically représentai as follows : 



