Bats.! 



MUSEUM OF ANIMATED NATURE. 



227 



ORDER CHEIROPTERA, OR BATS. 



We regard the Bats (Family Cheiroptera, Cuvier ; 

 Vespertilionidce, Gray) as constituting a distinct 

 order, as it stands in the Catalogue of Mammalia 

 in the ' Mus. Zool. Soc.,' 1838. 



The Bats, or Flitter-mice (Fledermauser of the 

 Germans ; Pipistrelli and Nottoli of the Italians ; 

 Chauvesouris of the French), are termed Cheiroptera, 

 that is, wing-handed {x*>?i a hand; irrepov, a wing), 

 because their anterior limbs are modified as organs 

 of flight. Of all the mammalia, the bats alone emu- 

 late the feathered tribes in their aerial endowments. 

 They are essentially flying Insectivora: in the air 

 they pass the active portion of their existence and 

 revel in the exercise of their faculties. Their organs 

 of flight, however, consist not, as in the bird, of stiff 

 feathers disposed in order and based upon the bones 

 of the fore-arm, but of a large thin membrane 

 stretched over and between the limbs, to which the 

 bones act as stretchers, like the strips of whalebone 

 in an umbrella, the tail in many species assisting 

 also. Of this membrane the bones of the arms and 

 hands are the principal supporters and levers of 

 motion— we say hands, because, though not graspers, 

 such must the anatomist consider them. All these 

 bones, those of the carpus excepted, are slender 

 and remarkably elongated, and here we refer to 

 the skeleton of the bat (Fig. 1015). The hu- 

 merus,/, is long and slender, but much more so is 

 the radius, g, the only complete bone of the forer 

 arm, the ulna, h, being reduced to a mere rudi- 

 ment. The carpus, i, consists of six bones in two 

 rows, the first row having two, the second row four 

 bones, on which are based the metacarpal bones of 

 the thumb, A, and of the fingers, I. These bones 

 of the fingers are very slender and of extraordinary 

 length, diverging from each other as they proceed. 

 They are. however, moveable upon the metacarpus, 

 and are not only capable of closing together, but of 

 being folded down in contact with the fore-arm. 

 The phalanges, or true finger-bones, m, carry on the 

 elongation of this framework, and taper to a point, 

 like the extremity of an angling-rod, unfurnished 

 with nails or claws. These fingers are essential not 

 only for carrying out the wing to a due distance, 

 but for keeping its margins stretched out, and for 

 folding it down when requisite. In some genera 

 the first finger consists but of one very fine bone, 

 the second finger consists of three : occasionally the 

 first finder is tipped with a very small hook-like 

 nail. The thumb, It, is free, and usually short, con- 

 sisting of a metacarpal and two digital bones, the 

 last of which is armed with a strong hooked claw. 

 Such then is the hand of the bat, essentially an 

 apparatus for flight. Thus designed and constructed, 

 rotation of the fore-arm would not only be an un- 

 necessary, but indeed an inconsistent endowment ; 

 its motion, therefore, is simply hinge-like, while that 

 of the shoulder is to a great extent rotatory. 



It will easily be conceived that, a membrane so 

 extensive as the wing of the bat will require for its 

 effective movements an extraordinary development 

 of the muscles which govern it. That part of the 

 skeleton, therefore, on which these muscles are 

 fixed is accordingly modified ; the clavicles, d, and 

 scapulae, e, are of great magnitude and strength ; 

 the sternum, or breast-bone, though narrow, has 

 a keel- like elevation along its anterior surface, ana- 

 logous to what is seen in birds, while its upper end 

 is developed into a manubrium, a, for the support 

 of the large clavicles, which are thus thrown far 

 laterally, the pectoral muscles being at the same 

 time exceedingly voluminous ; indeed the whole of 

 the osseous and muscular structure of the bat is 

 concentrated upon its organs of flight. The hinder 

 limbs can scarcely be regarded as organs of loco- 

 motion ; they principally serve, in conjunction with 

 the tail where present, to keep the membrane duly 

 expanded — they are therefore comparatively feeble : 

 the toes are five in number, and armed with sharp 

 hooked claws, by which the animal suspends itself 

 while at rest in its retreat. When with folded wings 

 the bat attempts to proceed along a level surface, 

 its movements, though tolerably quick, are awkward 

 and shuffling; and it uses the claw of its thumb as 

 a hook for catching hold of any irregularities in 

 order to drag itself along : hence, on a smooth po- 

 lished surface it is greatly embarrassed, but in the 

 hollows of trees, in the crevices of masonry, and in 

 rough chinks or fissures, it can climb and crawl 

 about with considerable facility, as also about the 

 wire-work of a cage, as we have often witnessed. 

 The ground, however, is not the destined province 

 of the bat — the air is its home ; it is here that these 

 singular creatures are all alertness, pursuing their 

 insect prey, and uttering their short sharp cry as 

 they wheel in circling flights, or perform their 

 abrupt and zigzag evolutions. 



In the bat, the senses of smell and hearing, as 

 might be concluded from the development and 

 complication of their respective organs, are wonder- 

 fully acute. In several extensive genera, with a 



view to the refinement of these senses, we see the 

 nose furnished with a membranous foliation or leaf 

 of most delicate structure, and often complex in its 

 arrangement ; while the external membranous ears 

 are large, expanded, and often united together, 

 having folds or an inner reduplication, and capable 

 of being folded down. (See Fig. 1016, the head of 

 Megaderma trifolium.) In short, both the osteo- 

 logical characters of the skull and the development 

 of the external appendages, traversed by multitudes 

 of nerves, announce the acuteness both of smell and 

 hearing. But these creatures have another sense, 

 that of feeling, so exquisitely refined as to require 

 especial notice. The wings of these creatures con- 

 sist, as we have stated, of a delicate and nearly 

 naked membrane of great amplitude ; and these, 

 as well as the membranous tissues of the ears and 

 nose, are abundantly supplied with nerves, and have 

 their sensibility so high, as to afford something like 

 a new sense which stands in the stead of sight. 

 The modified impressions which the air in quies- 

 cence or in motion, however slight, communicates — 

 the tremulous jar of the faintest current — its tem- 

 perature ; the indescribable condition of such strata 

 as are in contact with different bodies, are all ap- 

 parently appreciated by the bat. If its eyes be co- 

 vered up— nay, if it be even cruelly deprived of sight, 

 it will pursue its course about a room with a thou- 

 sand obstacles in its way, avoiding them all ; neither 

 dashing against the walls nor flying foul of the 

 smallest thing, but threading its course with the 

 utmost precision and quickness, and passing adroitly 

 through apertures, or the interspaces of threads 

 placed purposely across the apartment. This en- 

 dowment, which almost exceeds belief, has been 

 abundantly demonstated by the experiments of 

 Spallanzani and others ; it is the sense of touch re- 

 fined to an inconceivable degree of perfection, ren- 

 dering the bat aerial in feeling as in habits. 



Bats are all crepuscular or nocturnal ; during the 

 day they sleep in their recesses, hanging head 

 downwards, suspended by the hind-feet. Numbers 

 often congregate together on one common dormi- 

 tory, and in Java and other adjacent islands one 

 of the most extraordinary sights is that of a tree 

 literally loaded with a crowd of huge roussettes, or 

 flying foxes (Pteropus), all clustered together in 

 pendant rows along the branches. In our latitudes 

 the bats all bybernate, hanging in the same manner 

 as during their ordinary sleep ; but whether this 

 law of hybernation prevails among those species 

 which are natives of the hotter regions does not 

 appear to be satisfactorily determined; probably it 

 does, for the tenrec (an animal allied to our hedge- 

 hog) hybernates in Madagascar, its native country. 



The bats are extremely numerous, and are distri- 

 buted over every portion of the globe, excepting in 

 the coldest latitudes ; it is, however, in the warmer 

 regions that they are the most abundant, and attain 

 to the largest dimensions. 



We have said that the bats are insectivorous; 

 some, however, are bloodsuckers ; and some, as the 

 roussettes (Pteropus), eat fruit, plundering the gar- 

 dens of their choicest productions. It would seem 

 that some of the Brazilian bats also are frugivorous, 

 devouring the fruit of the fig-tree, and that it is 

 almost impossible to prevent the mischief, as they 

 will creep, like mice, under the netting spread to 

 protect the trees. 



In the bats the mammae are two, and pectoral ; 

 the dentition varies: the symphysis of the lower 

 jaw is firmly ossified, as in man and the ape tribe ; 

 a slender stylet {$, Fig. 1015) runs from the heel to 

 support the interfemoral membrane. The bats are 

 divided by Mr. Gray into five great sections or 

 tribes, as follows, under two primary heads : — 



I. Istiophori, or Leaf-nosed Bats.— Nostrils placed 

 in a bald space, often elevated behind into a leaf; 

 teeth acutely tubercular; index-finger not clawed. 



Tribe 1. Phyllostomina. Nose-disc expanded 

 into a leaf behind, simple, and pierced with the nos- 

 trils in front. 



Tribe 2. Rhinolophina. Nose-disc expanded into 

 a leaf behind, and with a pit or process between the 

 nostrils in front. 



II. Anistiophori.— Simple-nosed Bats. Nostrils 

 without a nasal leaf. 



Tribe 3. Vespertilionina. Grinders acutely tu- 

 bercular ; wings broad and large ; tail elongated 

 and inclosed iifthe large conical interfemoral mem- 

 brane ; upper incisor teeth near the canines, with a 

 central space. 



Each nostril placed in front of a groove, with a 

 spiral, convolute, outer margin lobed anteriorly. 



Tribe 4. Noctilionina. Grinders acutely tuber- 

 cular ; wings long and narrow ; body thin ; tail 

 thick, short, the tip appearing on the upper surface 

 of the large interfemoral membrane. 



Tribe 5. Pteropina. Grinders bluntly tubercular ; 

 nose simple ; nostrils slightly produced ; end of 

 index-finger clawed; head conical; ears simple; 

 wings long ; lower joint of thumb long, united to 

 the wing by a membrane ; interfemoral membrane 



short; tail none, or short. Fruit-ealing bats of 

 Indian Islands and Polynesia. 



Each of these tribes is again subdivided accord- 

 ing to the variation of minor points of structure, the 

 genera being arranged under each subsection ; but 

 to pursue the subject into these niceties would be 

 here out of place; we, however, recommend our 

 scientific readers to the 'Revision of the Genera of 

 Bats,' &c, by J. E. Gray, F.R.S., published in the 

 ' Magazine of Zoology and Botany,' No. XII. 



Of the first tribe (Phyllostomina), our pictorial 

 museum affords us several examples. 



1017. — The Crenulated Javelin-Bat 



{Phyllostoma cremdatimi). In the genus Phyllo- 

 stoma the canine teeth are very strong. Dental 



formula : — Incisors, - ; canines, -^- : molars, ^~ 

 4 1—1 5—5 



—32. There are two nasal appendages, one like 

 a horseshoe, the other like a leaf or spear-head, 

 rising up behind the former; the ears are large, 

 with a dentellated inner slip (oreillon, or tragus) ; 

 the tongue is bristled with papillae ; the tail is 

 variable in length, sometimes wanting. The pre- 

 sent species, of which the habits and exact locality 

 are unknown, is a native of America. 



1018.— The Greater Javelin-Bat 



(Phyllostoma perspicillalum). This species is a 

 native of Soutli America. Mr. Darwin found it at 

 Bahia. Of its habits we have no details. 



1019. — The Vampire-Bat 



(Vampirus spectrum). The genus Vampirus differs 

 from Phyllostoma in having one molar more on 

 each side in Hie upper jaw. Fig. 1020 shows the 

 characters of the incisors and canines. 



This species, the Andira-Guacu of Piso, is a native 

 of South America; its total length is about six 

 inches. Piso thus describes its habits :— These bats 

 " seek out every kind of animal and suck their 

 blood; but in Maranham there is a certain kind 

 which approaches by night the naked feet of men, 

 and wounds them for the sake of sucking human 

 blood. The bite is so slight and subtle, that the 

 wounded do not feel it before the bed, covered with 

 blood, gives token of the wound. So great a quan- 

 tity of blood flows from the envenomed bite, that it 

 can only be stopped with difficulty, and the peril is 

 imminent unless a cure by the prescribed remedies 

 be effected. The inhabitants first wash these 

 wounds with sea-water, and afterwards apply hot 

 ashes, or even cautery, if the blood be not stopped."' 

 Captain Stedman, who states that he was bitten, 

 thus describes the operation : — " Knowing, by in- 

 stinct, that the person they intend to attack is in a 

 sound slumber, they generally alight near the feet, 

 where, while the creature continues fanning with 

 its enormous wings, which keeps one cool, he bites 

 a piece out of the tip of the great toe, so very small, 

 indeed, that the head of a' pin could be scarcely 

 received into the wound, which is consequently not 

 painful; yet through this orifice he continues to 

 suck the blood until he is obliged to disgorge. He 

 then begins again, and thus continues sucking and 

 disgorging till he is scarce able to fly ; and the suf- 

 ferer has often been known to sleep from time into 

 eternity. Cattle they generally bite in the ear, but 

 always in places where the blood flows spontane- 

 ously. Having applied tobacco-ashes as the best 

 remedy, and washed the gore from myself and my 

 hammock, I observed several small heaps of con- 

 gealed blood all round the place where 1 had lain 

 upon the ground ; on examining which, the surgeon 

 judged I had lost at least twelve or fourteen ounces 

 during the night." 



From these and similar accounts, themselves a 

 little qvercoloured, have arisen extravagant repre- 

 sentations and false statements, to which too much 

 credit has been given; blood-sucking propensities, 

 moreover, have been attributed to the bats of Java 

 and other countries, without any authority ; and the 

 tongue, instead of the sharp lancet-like teeth, has 

 been regarded as the instrument by which the 

 puncture is made. D'Azara, speaking of the blood- 

 sucking bats of South America (and he is a faithful 

 describer), observes that " the species with a leaf 

 upon the nose differ from the other bats (of Para- 

 guay) in being able to run, when on the ground, 

 nearly as fast as a rat, and in their fondness for 

 sucking the blood of animals. Sometimes they will 

 bite the wattles and crests of fowls while asleep, 

 and suck their blood. The fowls generally die of 

 this, as gangrene is engendered in the wounds. 

 They bite also horses, mules, asses, and horned 

 cattle ; usually on the shoulders, buttocks, or neck, 

 as they are better enabled to arrive at those parts, 

 from the facilities afforded them by the mane and 

 tail. Nor is man himself secure from their attacks : 

 on this point I am able to give a veiy faithful testi- 

 mony, since I have had the ends of my toes bitten 



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