THE FLYING SQUIRREL 511 



from each otlier by the formation of their teeth, lips, nostrils, 

 heads, wings, and tails, have already been classified by naturalists, 

 but many, no doubt, still live unknown in their gloomy retreats, 

 for who is able to follow them into the obscure nooks of the forest, 

 or in intricate caverns, and accurately to observe them during 

 their nocturnal rambles? It may give an idea of their vast 

 numbers throughout the torrid zone, when we hear that in Ceylon 

 alone about sixteen species have been identified, and of these 

 two varieties are peculiar to the island. Unlike the sombre bats of 

 the northern climates, the colours of some of them are as brilliant 

 as the plumage of a bird, bright yellow, deep orange, or of 

 a rich ferruginous brown, thus contradicting the general belief 

 which attires nocturnal animals in vestures as dark as their 

 pursuits. 



The torrid zone, which produces the largest bats, also gives 

 birth to the tiniest representatives of the order, such as the 

 minute Singhalese ya.riety of Scotophilus Cor oviandelicus, which 

 is not much larger than the humble bee, and of a glossy black 

 colour. " It is so familiar and gentle," says Sir J. E. Tennent, 

 *' that it will alight on the cloth during dinner, and manifests so 

 little alarm, that it seldom makes any effort to escape before a 

 wine-glass can be inverted to secure it." 



The fur of this pretty little creature, like that of many other 

 bats, is frequently found infested with a most singular insect. 

 Unlike most parasites, which are either extremely sluggish in 

 their movements, or even condemned to utter immobility, the 

 velocity of the nycteribia is truly marvellous, and as its joints 

 are so flexible as to yield in every direction, it tumbles through 

 the fur of the bat, rotating like a wheel on the extremities of its 

 spokes, or like the clown, in a pantomime, hurling himself forward 

 on hands and feet alternately. To assist its mountebank move- 

 ments, each foot is armed with two sharp hooks, with elastic 

 pads opposed to them, so that the hair can not only be rapidly 

 seized and firmly clasped, but as quickly disengaged as the 

 creature whirls away in its headlong career. But the strangest 

 peculiarity of the nycteribia is the faculty which it possesses of 

 throwing back or inverting its head so completely, that the 

 underside becoming uppermost, the mouth, the eyes, and the 

 • antennae are completely hid between its shoulders, and then again 



