694 é GEOLOGY. 
set up a rattling for the sake of enticing birds to them, but that 
they would slowly and cautiously approach their victim, or else 
lie in wait ready to give the fatal spring upon anything that came 
near. He believed that the rattle was in reality a detriment to 
the snake, except in so far as it served to call the sexes together, 
which he thought was most likely its true function. 
Fires as A Means or COMMUNICATING CONTAGIOUS DISEASES.— 
Prof. Leidy remarked at a late meeting of the Academy of Natural 
Sciences of Philadelphia, that at this time, during the prevalence 
of small pox, he was reminded of an opinion he had entertained 
that flies were probably a means of communicating contagious 
disease to a greater degree than was generally suspected. From 
what he had observed in one of the large military hospitals, in 
which hospital gangrene had existed, during the late rebellion, he 
thought flies should be carefully excluded from wounds. Recently 
he noticed some flies greedily sipping the diffluent matter of some 
fungi of the Phallus impudicus. He caught several and found 
that on holding them by the wings they would exude two or three 
drops of liquid from the proboscis, which, examined by the micro- 
scope were found to swarm with the spores of the fungus. The 
stomach was likewise filled with the same liquid, swarming with 
spores. 
GEOLOGY. 
Extinction oF Brrps IN MAURITIUS, rTc.—I believe I have 
demonstrated, by the’ examination of the bones which have been 
found in the recent deposits in the Mascarene Islands, an 
_ belong, for the most part, to extinct species, such as the dodo, 
solitaire, the aphanapterex (Fulica Newtoni), large parrots, ett, 
that these islands have once been part of a vast extent of land, 
that these lands, by little and little and by a slow depression, have 
been hidden under the waters of the ocean, only leaving visible 
some of their highest points, such as the islands of Mauritius, 
Rodriguez, and Bourbon. These islands have served as a refuge 
for the last representatives of the terrestrial population of these 
ancient epochs; but the species, confined in too limited a space 
and exposed to all causes of destruction, have disappeared by 
degrees ; and man has in some measure aided in their extinci®® 
Madagascar evidently was not in communication with we 
islands ; for when Europeans visited them for the first time, y 
the 
d which © 
