Quadrupeds. 2815 



only on the long-eared bat (Plecotus auritus) and the horse-shoe bat (Bhinolophus 

 Ferrum-equinum), which he procured from the vaults under the fortifications of 

 Geneva. When the horse-shoe bat attaches itself to a wall it contracts its body, and 

 wraps itself up in its fur in such a manner that it might be taken for a black chry- 

 salis. The long-eared bat appears less careful of itself, and first makes use of its 

 hind feet, and then those before, in order to affix itself to a wall. The temperature 

 of the vaults which served them for a habitation was between 50° and 57° Fahr. ; 

 that of the external air between 27° and 30°. M. Jurine exposed some of these ani- 

 mals to a temperature between 36° and 39° : several of them perished, and others fell 

 into a state of torpidity, from which he was not able to rouse them by any touching, 

 though a gentle current of air directed against them caused them to make a move- 

 ment by drawing back the whole body on the hind legs : he had also observed the 

 same effect on mice. He also remarked that the approach of a candle agitated and 

 awakened them, and a violent agitation of the air by which they are surrounded 

 makes them speedily take wing. During the torpid state of these animals, no move- 

 ment is observed which can indicate that they breathe. A small horse-shoe bat, a 

 large one of the same species, and a long-eared bat, were placed on a stone, and ex- 

 hibited signs of life at different periods, but their inspiration and expiration were 

 extremely irregular, particularly those of the long-eared bat. There is a striking 

 difference between the position of these two species of bats when they fix themselves 

 against any object. The horse-shoe bat fixes itself at once, with its head down and 

 its legs upwards ; while the long-eared bat turns itself round quietly, in order to as- 

 sume very often an oblique position. De Jurine then proceeds with the experiments 

 of depriving them of sight, following the example of Spallanzani, who published a 

 small work on this subject. De Jurine, however, extended his experiments further 

 than Spallanzani, from which we gather the following. De Jurine placed several 

 willow-twigs, three feet in length and six inches apart from each other, and let loose 

 two bats, which passed and repassed between them without touching them with their 

 wings, and when their flight was ended always attached themselves to the same 

 cornice. He then cut out their eyes, during which operation the long-eared bat suf- 

 fered a considerable hemorrhage from the ocular orbits : being let loose in that state, 

 they still flew to the same interstices : these being barred up, they made choice of 

 others, through which they passed several times, always avoiding to touch the twigs 

 with their wings, and for that purpose they passed obliquely. The long-eared bat 

 sometimes stretched out its neck, and made choice of the object to which it wished to 

 attach itself; it also did this before it was blinded: it often applied one of its hind 

 paws to its eye, collected the liquid which exuded from it, and then applied it with 

 avidity to its mouth. These two bats lived a long time after they were deprived of 

 sight. Two long-eared bats — the one blind and the other having the perfect use of 

 its eyes — were let loose together : the blind one always followed its companion, even 

 observing the smallest sinuosities of its course : the bat which saw passed between 

 the twigs with less delicacy than the blind one. De Jurine then extended a net with 

 large meshes, first making a breach in it : the bat which saw passed through it imme- 

 diately, but the blind one stopped short, went all over the net, and, having found the 

 hole, passed through without touching it, and then joined his companion, which it 

 afterwards followed wherever it flew. Of what use (says M. de Jurine), then, is sight 

 to the bat ? and what is the organ which supplies its place ? He then extended his 

 experiments to the organs of hearing and smell. Having put a small hood on a long- 



