OF THE UNITED STATES 441 



reason to protect them, as bats destroy simply millions of destruc- 

 tive insects. Yet the smaller species of temperate countries 

 rarely seem to ever increase in number to any marked extent. To 

 be sure, they have but one or two young at a time, and in the 

 north breed but once during the season; yet with so few enemies, 

 and man not in the list of these, one would think that the smaller 

 species would become very numerous, especially in those locali- 

 ties where the majority of the conditions were favorable to them. 

 During recent years a number of new species and subspecies of 

 bats have been added to the fauna of the United States, and 

 doubtless not a few still remain to reward the search of the intel- 

 ligent collector. This likewise applies to the discovery of the fos- 

 sil remains of bats, as bones of insectivorous varieties of them 

 have already been found in the tertiary deposits in various local- 

 ities. 



