40 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
ratory ; they have a hydrostatic function when the body is expanded ; 
they produce numerous amoebocytes; and finally, the presence of uric 
acid and urates shows that they have excretory functions comparable to 
those of the renal organs of Vertebrates and of the Malpighian tubes of 
insects. 
Asterid Development. — Prof. E. W. McBride * * * § criticises Prof. S. 
Goto’s account f of the development of Asterias pallida , and re-asserts 
two of his previous conclusions (1896), — (a) that the right hydrocoele is, 
after its origin, entirely isolated from the anterior coelom, and (6) that 
the radial peri haemal canals have at first a ccelomic connection. 
Ccelomic Cavities of Asteroids.^ — Prof. S. Goto has studied the 
development of Asterina gibbosa, and has compared his results with 
those reached by McBride, and with his own previous observations on 
Asterias pallida. The differences between the two species may be 
shown by the following diagrams, in which the four smaller squares 
represent the four portions of the larval enterocoel. The broken lines 
represent the partitions, real or imaginary, that obtain in the larva ; 
the complete lines represent the partitions that persist in the adult. 
The names of the different cavities are written within the parts of the 
larval enterocoel from which they arise. The diagram may be directly 
derived from nature by viewing the larva from the ventral side and 
supposing the body to be cut open in the dorsal mid-line and spread 
out flat, and imagining the larval enterocoels as squares. 
Posterior 
Perioesophageal 
enterocoel 
Dorsal sac 
\ Epigastric 
\ ent. cl. 
Secondary left 
postr. ent. cl. \ 
Hydrocool 
Circular 
ent. cl. 
Axial 
sinus 
Anterior 
Asterias pallida 
Pericesophngeal 
enterocoel 
Epigastric 
Dorsal sac 
ent. cl. 
Circular 
ent. cl. 
Secondary left po 
str. ent. cl. \ 
Perihcemal ca 
vities partly \ 
Hydrocoel 
Axial 
sinus 
Asterina gibbosa 
Ri 
Hybridism in Sea-TJrchins.§ — Mr. H. M. Vernon publishes the 
results of researches on the relation between hybrid and parent forms 
of Echinoid larvte. The majority of his observations were confined to 
three species, Strongylocentrotus lividus , Sphserechinus granularis , and 
Echinus micro tuber culatus. These species are not separated from each 
other by any rigidly defined physiological barrier, for there is present 
* Zool. Anzeig., xxi. (1898) pp. 615-7. 
t Journ. Coll. Sci. Tokio, v. Cf. this Journal, 1897, p. 129. 
X Annot. Zool. Japon., ii. (1898) pp. 79-83 (3 figs.). 
§ Phil. Trans., cxc. (1898) pp. 4G5-529. 
