REVIEWS. 253 
vindication of his own discoveries presents itself to him in the aspect of 
a “ parental duty” (p. 267). 
In many respects the present work appears to us to be far in advance 
of any previous one upon the subject. Together with clear, concise, and 
sufficient descriptions of the characters which serve to distinguish the 
species, are combined so many interesting observations on the habits of 
the animals, that the work possesses the rare merit of combining scien- 
tific accuracy with a large amount of popular instruction. We can only 
give one or two brief illustrations. It is well known that certain univalves, 
when suddenly dislodged from floating weeds, spin a thread by which, 
like the spider, they are able to regain their resting-places. Mr. Jeffreys 
records a similar habit in Sphcerium lacustre ( Cyclas cciliculata), which also 
uses its foot in ascending the sides of an aquarium, and even in creeping 
along, suspended from the surface of the water, just in the manner 
common to many gasteropods. Bivalves, with the exception, perhaps, of 
some species of oyster, are supposed to be purely aquatic in their habits ; 
yet the author records, on the authority of Nilson, that Pisidium pusillum 
is in Sweden frequently found living between the bark and the wood of 
fallen trees in moist places. Helix pulchella, a minute snail common in 
Britain, is reported to occur in Siberia, Italy, Corsica, Madeira, North 
America, Cashmir, and Thibet. Some of our little wood-snails, H. aculeata 
and H. fusca, appear, on the Continent, to adopt habits not generally 
known in this country : they ascend in spring the trunks of trees, live 
during the summer amongst the higher branches, and in the autumn save 
themselves a long and laborious descending journey, by dropping with 
the falling leaves to their place of winter retreat. 
The snail has not generally found much favour in the eyes of poets ; 
yet the author avails himself of the assistance of a friend to devote some 
pages to the aesthetic aspect of bis subject, with especial view, as he asserts, 
to the gratification of his fair readers. Homer, Goethe, and “ Shakspere,” 
are cited. From the “Venus and Adonis” of the last-named a fine 
simile is given : — 
“ Or as the snail whose tender horns being hit, 
Shrinks backward in his shelly cave with pain, 
And there, all smother’d up, in shade doth sit, 
Long after fearing to creep forth again ; 
So at his bloody view her eyes are fled 
Into the deep dark caverns of her head.” 
We anticipate with pleasure the volumes on the “ Marine Mollusca of 
Britain,” by the same author, and conclude this brief notice with a word 
of commendation for artist and publisher. Mr. Sowerby’s plates, more 
especially the beautiful coloured frontispiece, deserve special notice ; and 
of Mr. Van Voorst we can only repeat what has been said a hundred 
times before, — that what ink and paper can do to render useful reading 
pleasant, he has done. 
