THE BATS 



(CHIROPTER,\). 



by tike posscssnn of 



■d tai, aad capiile of 

 wiililw; two pcdocsl nun 



hf a. Twhraur aitarhfd to tbe body, and cn M w I j p ako to tbe 

 ntnidfd by tbe idBukabir donpttfd ^JEPls of ilie ineJiBbB; 

 - dsooidal phoenta. 



The body in the bats is in general thidi- 

 set and cxMnpact. the^ neck ^ort, the skull 

 radier small dian large, somewhat elongated. 

 Owii^ to the lemarkaUe devdcpoient of 

 various appendages of the skin, however, 

 as well as to the broad muzzle, the head 

 in the lining animal a{^)ears to be rather 

 laige. TTje eyes depart finom the general 

 rule for nocturnal animak in being ratho' 

 small, sometimes even very small: the eats 

 are always large, crften peculiarly devel- 

 oped; the nose is sometimes naked, and 

 situated at the end of the snout, snn^imes 

 adorned in a singular manner with flaps erf 

 skin supported by cartilage. 

 ' The brain-case is mostly rounded, and 

 finequently di\-ided (mtn the fecial regi<xi by 

 a marked constriction. The CH^Mt is mostly 

 cootiniKMS with the temporal fossa or de- 

 pression at the temfJe. and it is only rardy 

 bounded by a narrow external bony rii^. 

 The structure <^ the fyfTnaxilla is often very 

 peculiar. Only in rare cases do the two pre- 

 maTcilbry bones meet in the middle: for the 

 most part the>' are separated by a wide in- 

 terval so that the upper incisors are placed 

 quite to the side, and often they are reduced 

 to small bony scales which scarody cut the 

 giuns. 



The dentition bdoi^ to the insectivorous 



type, and evoi that of the flying-foxes, which 

 we leave out of account in the meantime, can 



( be derived therefrom. .All the other bats 



j may. without heataticMi, be de^;nated as 

 flyii^ Insectivora. 



1 The nimiber erf" the teeth varies in an ex- 

 traordinary manner, ftxMn 24 to 38 fcN- the 



I total, but the numbos 32, 34, and 30 are 

 diose by which the u>tal is most fictjuendy 

 rep re sented. Twent\--three <rf" the sixty-sevoi 

 genera that have been distinguished, that is, 

 mme than one-third of the whole, have 32 

 teeth. Besides the m^inal deviaticMis. e^ie- 

 ciaDy in the mnnber of die mcJars, the dis- 

 dnctiaas diiefly depend up<» this, that in 

 many genera many incisors and {MioncJars 

 drop out very early, or are not nqJaced at 

 the change of teeth. The indsors are mostly 

 very small, in the upper jaw placed, as we 

 have seen, to the side, and there also pecu- 

 liarly ape to disappear. The canines, which 

 are always present, are large, recurved, and 

 provided widi cuttit^ e*%es. in many genera, 

 as notably in the vampyres. very large and 

 prominent: the prenxJars sharp and ccHiical: 

 the molars ftunished with two or three pointed 

 cu^ps, which are so arrai^ed as to fit dosdy 

 into one anodier, so that they do not get 

 ground away by use. but are k^>t always 

 sharp. The dentition is thus ^>ecially adapted 



