50 



Cheikoptera.- 



-MAMMALIA.- 



-ClIEinOPTERA. 



puiniitteJ to Uy about, wliile various obstacles were 

 placed in their way. Even in this luiliappy condition 

 the poor creatures avoided every hiuderance, know- 

 ingly turned sharp corners, and passed through threads 

 suspended from the ceiling of an apartment, when the 

 intervening spaces between the several cords scarcely 

 exceeded in width the lateral diameter of the animals' 

 bodies from wing to wing. The results of these experi- 

 ments have been since confirmed. The astonishing 

 plienomena thus exhibited at first induced Spallanzani to 

 believe in the existence of a sixth sense, and this opinion 

 appeared to receive general fixvour. It was reserved, 

 however, for the illustrious Cuvier to suggest that the 

 faculty in question resided in the winged and inter- 

 femoral expansions of the skin, and was immediately due 

 to the high sensibility of that structure. This membrane 

 was then, as now, well-known to be extensively supplied 

 with nerves, but it still remains to be demonstrated 

 wlicther these nerves terminate in special tactile cor- 

 puscles, or touch bodies, such as Wagner not long ago 

 discovered in the tips of the human finger, or whether 

 any other specialization of neural tissue may not be pre- 

 sent. In the phyllostomes, or leafy-mouthed bats, the 

 tongue presents a curious sucking apparatus, consisting 

 of numerous processes on the surface; and these acting 

 together enable them to draw in the juices of the 

 animals or fruits on which they feed. In regard to the 

 digestive organs we find modifications of structure co- 

 ordinating with the varying characters of the teeth in 

 the two principal cheiropterous groups. Those feeding 

 on insects present a simple stomacli, such as we see in 

 the ordinary Carnivora, whereas this organ in the fru- 

 givorous species displays characters more in harmony 

 with the complicated stomach uf vegetable-feeding 

 quadrupeds. 



The habits of the bat family are nocturnal or crepus- 

 cular. During the day they lie concealed in dark 

 recesses, and are to be souglit for in the hollow cavities 

 of trees, in holes of walls, and in rocky caverns; having 

 an especial liking for ancient ruinous buildings, among 

 whose architectural irregularities they discover most 

 aiipropriate hiding-places, suspending themselves by 

 their hind feet, the head being directed downwards. 

 As the shadows of evening approach with gradually 

 ducpening gloom and silence, our twilight-loving friends 

 steal forth from their various snug retreats. The soft 

 moist air of closing day, no longer heated by the 

 summer's sun, is favourable to the chase, while the 

 accumulating sweetness of the balmy air, aggravated, 

 it may be, by the occasional hnm or buzz of some 

 insect wanderer as it flits by the lonesome retreat of a 

 half-awakening phyllostome, can no longer be resisted. 

 The contracted crumpled-np wings are now unfolded ; 

 the drooping auricles become expanded and erect ; the 

 hour for action has arrived, and one by one each issues 

 forth with comforting expectancy. Such being the 

 preparatory attitude and behaviour of our aroused 

 phyllostome, let us now direct our thoughts to the 

 objects of pursuit — what of them ? Thus may wc 

 soliloquize. Poor insects ! you too have issued forth 

 on your self-seeking errands. Hither and thither yon 

 glide on in dreamy unconsciousness of the destiny that 

 awaits you. But in carrying out nature's provision for 



your abundant increase, you have, as it were, exceeded 

 the proper bounds. Though we acknowledge this 

 excess is more apparent than real, you cannot entirely 

 lay claim to our sympathy. We admit it is no fault of 

 yours, yet, there you are, sometimes disputing possession 

 of the air by your intolerable profusion. You have 

 propagated too fast. Like a healthy shrub you have 

 vegetated too actively, and, in a numerical point of 

 view, your very budding outbids all human calculation. 

 To us your success in this particular has become a 

 nuisance, and our welfare is involved in ymu' partial 

 abrogation. I am glad to see the cheiropterous des- 

 troj'ers are at hand, for to them your multiplicity is an 

 occasion of rejoicing. Talk of destruction ! In early 

 days the swift- winged arrow did its appointed work, 

 and to-day, alas ! the deadly rifle slays its numerous 

 human victims. But watch yon tin}' vespertilio, see 

 with what skill she steers her rapid flight. One after 

 another each fluttering victim disappears, as with 

 sudden stroke its course is finished by the flittermouse's 

 grasp. Sic trcmsii gloria insectorum. Yet this mode 

 of living is imposed upon the Vespertilio as a wise 

 necessity. She not only purifies the air of super- 

 abounding insect forms, but at the same time, secures 

 her proper sustenance; she supports her delicate fabric 

 by the legitimate employment of her means, and 

 accomplishes this purpose without occasioning pro- 

 longed pain or unnecessary torture. How suggestive 

 and beautifully true to nature, therefore, are the sacred 

 psalmist's words — " Thou openest thine hand, and 

 fillest all things living with plenteousness." 



Another habit among Cheiroptera must not pass 

 unnoticed — we allude to hybernation. This remark- 

 able state of inactivity occurs during the winter season, 

 and is a provision of nature not so much brought about 

 by the mere existence of cold, as by the circumstance 

 of the supply of insect food being stopped. It is well 

 known, indeed, that some animals belonging to the 

 insectivorous mammalia, properly so called, hyberuate 

 in tropical countries during the summer months, for the 

 excessive heat and dryness of the atmosphere causes 

 the same scarcity of insect life. Whatever may be the 

 explanation of the changes produced in animals so 

 circumstanced, it will be readily imderstood that those 

 occurring under opposite conditions must be equally 

 astonishing. Here we have a strangely-modified 

 existence — a meagre semblance of vitality — at the 

 portal of whose doors death seems ever ready to enter 

 in and claim possession. Suspended in the secret 

 recesses of his temporary grave, our little bat expe- 

 riences the chill of those coming events that cast 

 shadows before them. But a short time since we 

 watched his aerial flittings, as he joyously snapped up 

 his prey; but his pastime is over, not a few insects 

 have perished, and the larvae of others lie buried in the 

 earth, hoping to assume the more perfect imago form 

 in the approaching spring. Left in this apparently 

 forlorn condition, the bat gives itself over to a pro- 

 found repose, while a series of physiological changes 

 steal over him such as Professor Owen has thus 

 f;iithfully portrayed — " The breathing becomes gradu- 

 ally slower than in ordinary sleep, the pulsations of the 

 heart diminish in force and frequency, the supply of 



