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POPULAR SCIENCE REVIEW. 
ghalese to species of the genera Littorina and Cerithium. Similar sounds have 
been observed in South America ; and a recent observer in the North, about 
Vancouver’s Island, has discovered the existence of a similar musical mollusk 
in an arm of the sea running out of Victoria harbour. The sound was com- 
pared to that of a Chinese kite when flying, and which is produced by fixing 
pieces of metal to the kite’s tail. The Indians were well acquainted with the 
sound, and referred it, like the Cinghalese, to a shell-fish, but the observer had 
not hitherto been able to obtain specimens. 
The Young Fry of Anodonta Cygnea. — A remarkable fact in the history 
of this fresh-water mussel has been brought to light, viz., that the young 
fry are parasitic upon fishes. At the time of the exclusion from the ovum, 
says the Rev. W. Houghton, they keep constantly snapping together their 
valves, reminding one of the somewhat similar action of the birds’ heads 
upon some of the marine polyzoa. After it has once snapped upon the fin 
of an unfortunate fish it appears to be quite stationary. In this condition 
they appear to be identical with long-known little creatures called Glo- 
chidia, from the two hooks which they possess, and deemed truly parasites. 
These hooks being barbed, it appears that the little mussel, having once 
fixed upon a fish, is unable to re-open its valves. It is not known how 
long they remain in this parasitic condition, nor what changes they 
undergo before becoming adult anodonts. 
A cclimatization of the Silk-worm. — M. Blani, of the department of Marne et 
Loire, describes in the Revue et Magasin de Zoologie, the success with which 
a species of silk-worm ( Bombyx Cynthia) has been reared at Anjou. He de- 
scribes the appearance presented by the worms covering the branches of 
trees largely cultivated for that purpose. As many as 500,000 worms were 
placed upon the trees, and were doing well ; most of them had changed their 
skin three or four times, and some were already spinning their coccoons 
among the leaves. The tree on which these bisects feed is the Ailanthus, 
(natural order Xanthoxylaccee), a native of China, but very hardy and easily 
acclimatized. 
The Agricultural Society of Inclre et Loire has voted a sum of money for 
the cultivation of the mulberry, in order to increase the food of the true silk- 
worm (Boynbyx mori). 
Diseases of the Silkworm. — These occupy to a considerable extent the atten- 
tion of the silk cultivator, It has recently been discovered that uric and 
hippurie acid in the blood of the moth is a frequent cause of sickliness. The 
morbid product ceases to show itself when the insects are supplied with good 
food in the open air. 
New Mygale. — A. new British species of this genus of spider has been 
found at Brighton — Dysdera erythfina. Previously only one was known in 
England. These insects are remarkable for the caves some of them con- 
struct of earth, having a distinct door or lid ; and for the probably fabulous 
tales of some of the larger species’ propensity for catching birds. 
Borings of Limnoria terebrans. — Tins minute crustacean, which, though 
only two lines in length, exists in such numbers, and is so destructive in its 
boring propensities, as to cause great havoc to ships and submarine wooden 
structures, has hitherto been supposed to have received a check from Bethell’s 
patent creosote process. Mr. D. Stevenson has, however, stated, as the 
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