206 
SUMMARY OF CURRENT RESEARCHES RELATING TO 
The so-called teeth are pressed into the service of classification in a 
quite new way. 
In the three expeditions of the ‘ Travailleur ’ and the single one of 
the ‘ Talisman ’ there were collected about 630 Starfishes ; these belonged 
to 78 species, 61 of which were then new. The expeditions ranged from 
26 to 5005 metres in depth, from 46° to 15° of N. latitude, and 6° E. 
to 30° W. in longitude. 
Enteric Canal of Echinoderma.* — Dr. J. Frenzel has examined the 
enteric epithelium of various common Echinoderms, and finds that the 
cells are always cylindrical, and have characteristic brownish contents ; 
in some cases there are found between these cells migratory elements, 
which are principally secretory in character. When these are absent the 
cylindrical cells, which are always absorptive, are also secretory. No 
part of an Echinoderm gut can be said to be hepatic in function. 
Organogeny of Asterina gibbosa.f — Mr. E. W. MacBride gives a 
preliminary account of his observations on the development of this Star- 
fish, in which he deals especially with the later larval stages and the 
metamorphosis. He finds that the coelom becomes segmented, and that the 
arrangement of its divisions strongly recalls that of Balanoglossus. The 
right and left hydrocoele are compared to the collar cavities of Balano- 
glossus , and support for this view is found in the structure of Cembalo- 
discus , where the collar cavities are prolonged into long, pinnately 
branched arms, comparable to the radial canals of the water-vascular 
system of Echinoderms, with their rows of tube-feet. 
There is no haemocoele in A. gibbosa , all cavities lined with epithe- 
lium being derived from the coelom. The so-called dorsal organ is 
nothing more than an ingrowth of the left posterior coelom into the 
septum separating the posterior coelomic cavities from the axial sinus. 
It soon becomes solid, and from its upper end in the adult the genital 
rachis grows out. As the genital organs are formed as local swellings 
of this rachis, the ultimate origin of the sexual cells in Asterina , as in 
Vertebrates and Annelids, is coelomic epithelium. 
Ludwig, who discovered that the preoral part of the larva becomes a 
special locomotor organ, failed to observe that it is connected with a 
fixing organ or stalk. This arrangement persists for some time after the 
larva has acquired the adult form, for it is for a time unable to use its 
tube-feet, and when displaced from its attachment floats helplessly 
about. 
In Aniedon , which is likewise stalked, there is an excessive growth 
of the ventral surface, which rotates mouth and hydrocoele backwards 
and upwards away from the stalk, with the result of placing the mouth 
in a favourable position to catch pelagic prey. In Asterina , however, 
the body is flexed ventrally on the stalk, so that the ends of the hydro- 
coel meet round it, and the mouth is approximated to the substratum. 
The general conclusion to be drawn is that the abactinal plates of 
Asterina and Comatula are not comparable with each other, and that all 
conclusions based on the supposed homology of the dorsocentral in 
* Arch. Anat. and Physiol., Physiol. Abth., 1892, pp. 81-114 (2 pis.). See Zool. 
Jahresber., 1892 (1893) Echinoderma, p. 5. 
t Proc. Hoy. Soc. Lond., liv. (1894) pp. 431-6 (4 figs.). 
