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SUMMARY OF CURRENT RESEARCHES RELATING TO 
could be counted, were collected together at the centre of the lower 
surface of the disc and masked altogether the oral orifice. It is evident 
from their position that they can take no food during the period of 
gestation. M. Perrier has not been able to assure himself of the exis- 
tence of any special organ of adhesion to the mother, but it is clear that 
all the individuals are fixed to a membrane, which is given off from the 
body of the mother, by a soft peduncle. This membrane is, probably 
though not certainly, part of the membrane of the stomach which is 
protruded for the support of the young. The author suggests that the 
soft peduncle is the homologue of the stalk of Crinoids. 
Morphology of Skeleton of Young Asterias. — On this subject the 
author does not treat at the length which characterizes many contribu- 
tions on it, but he promises to return to it, and he asks a question which 
may require some answering, and that is why the Crinoidea want the 
so-called terminal plate which appears at such an early stage in Star- 
fishes and Brittlestars. 
Prof. Perrier next discusses the characters of the attached young of 
Asterias spirabilis Bell, and points out that, as in A. varia Phil., they do 
not acquire a mouth for some time. The stomachal sac and the brachial 
diverticula are filled with yolk-splieres. Special attention is given to 
the “ sacciform organ,” the “ plastidogenous organ,” and the sand-canal ; 
the development of the madreporic plate ; and the constitution of the 
subambulacral cavities and of the nervous system, for which we must 
refer the student to the memoir itself. 
In dealing with the budding of arms in Labidiaster radiosus. Prof. 
Perrier points out that in Starfishes we may see the following phe- 
nomena ; (1) In all species mutilated parts are reformed; (2) in a 
number one-half of the body is almost always being regenerated ; 
(3) an arm, being separated by accident, forms, in some species, a new 
Starfish ; (4) in some species, especially of Linckia, the arms become 
detached spontaneously, and each forms a new Starfish ; (5) the number 
of arms is not constant in the same species. All these characters can 
be paralleled by what may be seen among the Coelenterata, but it has 
always been held that all the rays of a Starfish were formed simul- 
taneously during larval life, and this has been taken as an important 
distinction. Now, however, we know that in Labidiaster new rays 
become budded from the disc among the old ones. In the author’s 
opinion this completely justifies the assimilation of the ramified body of 
a Starfish to the ramified body of a Hydroid or a Coral. 
In the systematic portion of his memoir Prof. Perrier recognizes five 
chief divisions — the Forcipulatae, Spinulosse, Valvulatse, Paxillosas, and 
Velatae, the last being a new group for the Pterasteridae, which he 
separates from the Paxillosse. Asterias Hyadesi Perrier is regarded as a 
synonym of A. spirabilis Bell ; its habit of guarding its young is a 
characteristic which is very common among the animals of the cold and 
temperate regions of the southern hemisphere. Among the many 
interesting forms which are discussed at length Cycethra simplex Bell 
may be specially mentioned ; this species, originally founded on a single 
specimen collected by H.M.S. ‘ Alert,’ is regarded by Prof. Perrier as 
one capable of considerable variation ; in an appendix, written after the 
publication of Mr. Sladeu’s report on the ‘ Challenger ’ starfishes, in 
