18 JEch. 
ECHINODERMATA. 
to be quite functionless in the adult. The Polian vesicles are lymphatic 
glands, and contract in order to send the blood corpuscles they produce 
into the water- vascular system. The blood-vascular system has no cur- 
rents in definite directions, but the liquid is simply kopt in motion by the 
cilia of the epithelium. It serves for the nutrition of the organs it 
traverses. 
Greenwood describes the action of nicotin upon Asterids, Ophiurids, 
and Crinoids. In the two latter groups the paralyzing action of nicotin 
is preceded by a phase of stimulation. 
Ludwig (2) contradicts the statements of Hartog as to there being an 
outward current from the madreporite of Echinoderms. As the result of 
experiments on Holoihuria tubulosa , S tichopus regalis , Sphcerechinus granu- 
laris , Asterina gibbosa and pancerii , Antedon rosacea , and on Auricularice , 
he finds that the current is always from without inwards, both in the 
pore canals of the madreporite, the calyx pores of Antedon , the dorsal 
pore of Auricularia , and in the stone canal. 
Prouho (2) finds that the sense of smell in starfishes is localized in the 
anterior non-locomotory tube feet of each arm, situated just behind the 
ocular plate. He proposes for these feet, or tentacles, the name “ palps.” 
[Cf. Biology, infra.] 
VI. — BIOLOGY. 
Bather (3) gives an account of the habits of Crinoids and their rela- 
tion to their environment. 
Cu^not (1) describes the method in which a starfish uses its pedicillarise 
for defence. A worm falling on the skin is seized and held by them, 
assisted by the spines. At the same time, the glandular cells of the skin 
pour out their poisonous excretion. The animal is held till it is dead. 
There is a relation between the abundance of pedicillariae in specimens of 
a given species from different localities and the richness of the fauna ; 
and the species with pedicillariae in the ambulacral groove never have 
commensal worms in this part. The most vulnerable parts of the body 
are the lymphatic glands ; in Astropecten these are protected by the 
paxillae, which act like the pedicillariae in seizing animals. Another 
method of defence in starfish is autotomy. The author describes the 
method in which starfish feed (pp. 40, et seq.). 
Fewkes (1) describes a Crustacean parasitic in the brood cavities of 
Amphiura squamata. It causes the ovaries of the Amphiura to degene- 
rate into an amorphous mass, in which no ova were recognisable, and the 
brood cavities become filled with the eggs and young of the Crustacean. 
Fewkes (2) describes the manner in which Strongylocentrotus drobachi- 
ensis , on the coast of Grand Manan, makes excavations in solid rock. 
The excavations are effected by the teeth and spines, combined with 
motions of the animal produced by waves and tide. The object is pri- 
marily protection, but secondarily a sufficient amount of water is retained 
in this way to cover the animal at half-tide. The coralline accompanying 
