490 top. 
warm hand as long as one has patience to hold them; they 
come up to the surface to breathe, and therefore do not con- 
sume much oxygen; they are perfectly hardy and easy to 
keep alive, eating small pieces of beef eagerly ; they occa- 
sionally change their skins, bringing the old skin over their 
heads and then swallowing them just as toads do. Their 
odd motions in the water, often poising themselves on the 
end of the tail or on one toe, are ver y amusing. They lay 
their eggs in the early spring either on or botos the leaves 
of water-plants. By the middle of August the young are 
nearly two inches long; they breathe at first with gills, but 
by September they come to the surface for air, as the older 
ones do. These tritons outlive all the other specimens in 
the tank, and they live so peaceably with their companions 
that they are invaluable as aquarial specimens. — To be con- 
uded. 

REVIEWS. 

THE DEVELOPMENT oF INsecTs.—Naturalists are now paying in- 
creased attention to the embryology of the articulates. After Rathke, 
Herold, and Kölliker had published their memorable works, there was an 
interval of twelve years between the publication, in 1842, of Kólliker's 
celebrated tract, entitled in Latin, «Observations on the first Genesis of 
Insects," and Zaddach's ** Researches on the Development and Structure 
of Articulated Animals; Part I. The Development of Phryganidan Eggs,” 
Leu atio 
PUN. and fhitalled, are the most elaborate we pied 
also * Researches on 



