1152 Life-histories of Northern Animals 



me rent the air with their shrill chirruping. My friend heard 

 nothing of this, the insect music lying beyond his limit of 

 audition." 



Birds, we know, are gifted with a great range of sounds to 

 express their varying emotions. Shrews and Bats, being in 

 general much more highly organized than birds, have probably 

 a much greater range of sounds. 



There is every reason to believe that they have at least 

 as many varied calls as a crow or a magpie, including even 

 a song for the season of love; and yet, because of our dull ears, 

 these things are in a sealed book, and the older we grow the 

 more curtailed is our power of peeping even at the covers. 



There is little evidence on the mating of Bats. Each 

 year in late August or early September they are seen in unusual 

 numbers, rushing about and chasing each other in great ex- 

 citement, for one or two evenings. Specimens collected at 

 such a time show, by the enlarged sexual organs, that now is the 

 rutting season. I saw this in a marked degree at Owen Sound, 

 Ont., on August 17, 1889. About nine in the evening the Bats 

 appeared in hundreds, and circled around the electric lights 

 like swarming bees. They were chasing each other in the 

 greatest excitement. I think that without doubt this was the 

 rut. Next evening it seemed to be over, and the number of 

 Bats went down to 3 or 4 in sight at one time. I am not sure 

 what kinds predominated, but have little doubt that the present 

 species was represented. I saw a similar demonstration at 

 Cos Cob, Conn., September 7, 1906. 



GESTA- Gestation is unusually long in all of this group, and ap- 



parently 10 months in the present species, as the young are 

 not born till June. C. L. Herrick says:" "Although northern 

 species mate ordinarily in autumn, eggs are not fertilized until 

 spring, when impregnation takes place." The observations on 

 which this is founded are not given; it implies a number of 

 unusual modifications. 



" Mam. Minn., 1892, p. 22. 



TION 



