BATS AND THEIR YOUNG. 651 



The Size of Bat Families. It is not known that bats make a nest 

 like birds, or that they have any other way of caring for their young 

 than by carrying them hanging to their fur whether during flight or 

 while suspended at rest by the legs. 



So we might naturally infer two things : first, that the young bats 

 would be born in a somewhat advanced condition so as to be able as 

 soon as possible to sliift for themselves ; and, second, that the number 

 produced at a birth would be small. 



The former inference would seem to be true, judging from the 

 large size of the little bats before birth, and the rarity of the cap- 

 ture of the mothers with young. In one case the two unborn young 

 weighed two-thirds as much as the parent, and the average of twenty 

 individuals gave the weight of the young as four-tenths that of the 

 parents. 



Upon the second point it is stated by Van der Hoeven (" Hand- 

 book of Zoology," vol. ii., p. 731) that "bats commonly produce one 

 or two young ones at a birth ; " but he does not say upon how many 

 observations the conclusion is based. 



Prof. Owen (" Comparative Anatomy of Vertebrates," vol. iii., 

 p. 730) I'ecords two observations of bats [Vespertilio emarginatus and 

 Y. noctula), with each one young, and concludes that this is commonly 

 the case with all bats. 



A collared fruit bat ( Cynonycteris collaris) produced a single young 

 February 27, 1870, and a second April 7, 1871.' 



In Jamaica Mr. Osborn observed several females of Jfolossus fu- 

 marius and Monophyllus poeyi^ with each one young.' 



The same observer mentions two other species [Macrotus Water- 

 housii, and Monophyllus Redmanii), without specifying the number 

 of young ; but we may infer that, as in the other cases, each female 

 had but one. 



In a single female of an undetermined Brazilian species I have 

 found one young ; and in each of forty females of the Nyctinomus 

 3rasiliensis (from Brazil) a single young. 



These are certainly facts in corroboration of the opinions of Owen 

 and Van der Hoeven, but let us not be hasty in generalizing from 

 them respecting all bats. 



In June, 1874, there were brought to me twenty females of the 

 "little brown bat" {Vespertilio suhnlatus). Each was found to con- 

 tain two little bats in various stages of development.' 



Finally, Prof. Putnam, of the Peabody Academy of Science, has 

 kindly allowed me to examine two females of the Lasiurus novehora- 

 censis taken in Massachusetts, on each of which were three young bats. 



The foregoing observations indicate that, while one is the more 



1 P. L. Sclater, "Proceedings of Zoological Society, 1870, 1871." 



* " Proceedings of Zoological Society, 1865," p. 81. 



8 I have since seen a bat of another species, to which were clinging two young. 



