292 
NATURAL HISTORY. 
“more fortunate than the Tetraodon, which can only return to its original condition by becoming a 
mere inert mass on the surface of the water, the Bat preserves all its faculties, or, what is better, 
increases their energy by becoming lighter and capable of more rapidity in flight.” This supposed 
advantage is at least questionable. — ^ 
CHAPTER I Y. 
FAMILY I V. — VESPERTILIONIDiE, OR TRUE BATS. 
T’lie Genus Vcspertilio and tlie Family Vespurtilionitlui— Characteristics : Nostrils — Tail — Ears— Dentition— Diet— Distribu- 
tion Long -eared Bat— Ears - Distribution — Asleep — In Captivity — BaRBastelle — Characteristics — Distribution — 
Habits — Flight — In Captivity — Big-eared Bat — Townsend’s Bat— The Genus Nyctophilm Its true place —Charac- 
teristics — Geoeeroy’s N YCTorn ile— Pipistrelle— Distribution— Diet— N octule— Natural Food— Mr. DanielTs Obser- 
vations— Serotine— Parti-coloured Bat — Hairy- armed Bat — Negro Bat— Kuhl's Bat— Nilsson’s Bat— 
Coromandel Bat— Thick-footed Bat— Temminck’vS Bat -Welwitsch’s Bat— New Zealand Bat— Mouse- 
coloured Bat— Natterer’s Bat Daubenton’s Bat— Whiskered Bat— Black and Orange Bat— Painted Bat — 
Harpy Bat— Red Bat— Sciireiber’s Bat— Brown Pig-Bat Straw coloured Bat. 
LiNNdSUS, in his “ Sy sterna Natune,” united all the Bats known to lain (with the exception of a 
single species, which, by a curious perversion of judgment he referred to a distinct genus, and placed 
in quite a different order) under the single genus Vespertilio. Later writers, finding it necessary, as 
their knowledge of these animals increased, to divide the Bats into many genera, have gradually, as 
it were, cut off portions of the old Liu mean genus and given them new names, always retaining the 
old name for the group which might be considered to include the most typical forms of the original 
genus Vcspertilio , the ordinary Bats of European countries. Of these, only two are noticed in the 
last edition of the work of the great Swedish naturalist, and even these are now referred to two 
distinct genera, and the generic name of Vcspertilio is now retained by only one of the few species 
with which Lin mens was acquainted. The genus, however, as at present restricted, contains a great 
number of species, all of wliich present the characters of what; may be called an average Bat, forming, 
as it were, the centre (or part of the centre) round which the other groups forming the order may be 
ideally arranged, and hence it very appropriately bears the old name Vcspertilio, as Bat par excellence , 
constitutes the type of the family V espertilion id<e, and gives its name to the V espertilionine 
alliance. In point of fact the genus Vespertilio and the family Vespertilionkhe may be regarded as 
the ideal centre of the whole order. As in other groups of the same 
kind the number of species contained in the family is very considerable, 
and their structural differences are generally minute, these, indeed, being 
the characteristics usually presented by what are called typical groups, 
the study of which is on this account attended with peculiar difficulties. 
Except in one Australian genus (Nyctophilns), which has been 
removed here from among the Megaderms by MM. Tomes and Dobson, 
the nostrils in the Yespertilionidse are simple round or crescentic 
apertures placed at the extremity of the muzzle, and not surrounded by 
leaf-like appendages. The tail is always long, contained in the mem- 
brane between the legs, wliich it traverses from base to apex, usually 
leaving a single joint projecting beyond the membrane ; the cars are 
of moderate or large size, are generally separate, and are furnished 
with large tragi. With regard to the teeth, the upper incisors are 
separated in the middle by a wide space and placed close to the canines. The number of incisor 
teeth in the upper jaw varies, being generally four, standing in pairs in the pre-maxillary hones, 
but in some species there is only one incisor on each side, and this difference may not be associated 
with any other characters sufficient to justify the generic separation of the species. The lower in- 
cisors are almost always six in number ; one genus only has four. The canines are of moderate 
