144 THE CANADIAN NATURALIST. [April 



REVIEWS. 



" Monogram of the Bats op North America." By H. 

 Allen, M.D. Washington : Published by the Smithsonian In- 

 stitute. 



This is a valuable contribution to our knowledge of a group of 

 animals little studied, though of great interest. As an incite- 

 ment to their study, we take the following extracts from the 

 introduction : — 



Among the numerous agents which Nature employs for restrict- 

 ing the excessive increase of the insect world, the bats hold a 

 conspicuous position. Eminently adapted to an animal regimen, 

 the vast majority of these animals are exclusively insectivorous in 

 their habits. Mosquitos, gnats, moths, and even the heavily- 

 mailed nocturnal Coleoptera, fall victims in large numbers to their 

 voracious appetites. Certain members of the order, such as flying 

 Foxes (Pteropodld^e), are strictly frugivorous, it is true; and 

 others, as the Dog-bat of Surinam (yoctula leporina), classified 

 as an insect-eating bat, partakes occasionally of fruit in addition to 

 its more animal diet. None of the species found in this country, 

 however, are known to subsist on any other than insect food. In 

 this respect they hold a decided relationship to certain birds ; and 

 it is interesting to observe how, under different circumstances, 

 these widely-separated animals serve us to the same end. The func- 

 tions which the latter perform during the day, the former assume 

 in the evening. The latter prey upon the diurnal insects, while 

 the former feed exclusively upon the crepuscular and nocturnal 

 kinds. The disappearance of the birds of day is a signal for the 

 advent of the dusky host, which, as it were, temporarily relieve from 

 duty their most brilliant rivals in guarding the interests of Nature. 



But, while thus connected with birds in their position in the 

 world's economy, bats have none of that grace of form or beauty 

 of coloring so characteristic of the others. Their bodies are clumsy 

 and repulsive ; their hues are dull and unattractive ; nor can the 

 eye dwell with pleasure upon their grotesque and awkward motions. 

 This aversion — so universally evinced toward these little animals 

 — is heightened by the associations of the time and place of their 

 daily appearance. Attendant, as they are, upon the quiet hours 

 of twilight, when the thickening gloom is conducive to the develop- 

 ment of superstitious feeling, bats have always been associated 



