48 THE AMERICAN NATURALIST. (VOL; XXXIII. 
Lastly, Dr. Goto discusses cavities of ‘‘mesenchymatous ” 
origin. Under this heading he includes the peribranchial cav- 
ities surrounding the dermal gills, or papulæ, and the radial 
perihemal canals, together with the outer perihzmal ring. 
These spaces, according to him, originate entirely independ- 
ently of the ccelom by the hollowing out of originally solid 
masses of mesenchyme cells. The inner perihzemal ring, on 
the contrary, is an outgrowth of the axial sinus. 
Seitaro Goto confirms my statements as to the total want of 
homology between the aboral poles of the asteroid and crinoid, 
the origin of the axial sinus and the stone canal, and the per- 
sistence of a communication between them, and the origin of 
the pericesophageal coelom and of the inner perihzemal ring. 
On the other hand, the results of my investigations, which 
seemed to me the most interesting and important, namely, the 
primitive segmentation of the ccelom, the existence of a right 
watervascular rudiment or hydroccele, the presence of a per- 
manently fixed stage in the ontogeny, and the denial of the 
existence of any spaces of mesenchymatous origin, are not 
confirmed by Goto. | 
It will conduce to brevity and clearness if I state shortly 
and definitely my position with regard to this discordance in 
opinion. I am convinced, from the general outline given by 
Goto, that the development of Asterina gibbosa and the devel- 
opment of Asterias pallida are in all essential points identical 
in character. I have submitted my own sections to reéxamina- 
tion, after reading Dr. Goto’s paper, and find them decisive ; 
and I find enough imperfection in Dr. Goto’s methods to more 
than account for all the differences between us. 
My work was based on hundreds of complete series of sec- 
tions of larva fixed by a method which was selected, after a 
long series of trials, as preserving the outlines of the organs 
with the sharpness of the lines in a steel engraving. I find 
no evidence whatever that Dr. Goto examined anything com- 
parable to the number of larvæ seen by me, and the method 
= of preservation adopted by him is one of the worst suited for 
the purpose. 
3 > not t question the ey of Dr. Goto’s statement as — 
