THE FLYING FOX, OR ROUSSETTE. 127 
“ Considering how little their vision is adapted for day duty, it was interesting to notice 
the systematic manner in which they directed their flight: one which arose some time 
after the others, taking immediately the right direction to follow and join the main body 
of fugitives.” 
In this latter passage is mentioned one distinguished peculiarity of these creatures, 
namely their habit of flying in long lines, somewhat after the manner of rooks returning 
to roost— 
“The blackening train of crows to their repose.” 
One bat seems to take the lead, and the others follow at short and irregular intervals, 
pursuing the same course as their pioneer. 
The bats which belong to this genus (Pteropus) are remarkable for the fact that they 
possess fewer vertebre than any other known mammalian animal. In the entire spinal 
column, there are but twenty-four of these bones; this paucity of number being caused 
by the entire absence of a tail. 
The hair with which the bat tribe is furmished, is of a very peculiar character, and 
although closely resembling the fur of a rat or mouse when seen by the unaided eye, is 
so unique in aspect when seen under a microscope, that a bat’s hair can be detected 
almost at a glance. Each hair is covered with very minute scales, which are arranged 
in various modes around a central shaft. 
The accompanying figure exhibits the central portion of a hair taken from one of the 
Indian bats, magnified five hundred diameters, or two hundred and fifty 
thousand times superficially. Near the root, the hair is almost devoid of 
these scales, and therefore appears much smaller than in the central and 
terminal portions. Some of these external scales bear a close resemblance 
to the scales which are placed on the surface of a butterfly’s wing ; but 
can easily be distinguished from them by their smaller size, and the absence 
of the striated markings that are found on the scales of the butterfly’s wing. 
The strange similitude between the bat’s hair, and the plant which is 
popularly known by the name of “Mare’s-tail,” cannot but strike any one 
who is in the least acquainted with botany. It may be, that so remarkable 
an outward resemblance would not exist unless there were some cause, at 
present hidden, which would account for it. 
Before leaving the study of the bats, we must take a cursory view of 
the strange condition of life in which these animals pass the colder months 
of the year, which condition is known by the name of hibernation, because 
it takes place in the winter. 
The insect tribes on which the bats chiefly subsist, and wholly so in this 
country, are either quiescent during the winter months, or are abroad in 
such lmited numbers that they could not afford a subsistence to the bats 
or swallows. The latter creatures meet the difficulty by emigrating to more 
genial lands, and there finding the food which they would lose in these cold 
climes ; but the former are obliged by the laws of their being to remain mM yyy op 
the country where they were born. It is evident, therefore, that unless some prawn Bat. 
provision were made for them during the insectless time of year, every bat 
would perish of hunger. 
Such a provision exists, and exerts its power by throwing the bats into a deep 
lethargy, during which they require no food and take no exercise, but just live through- 
out the winter in a state of existence that seems to partake more of the vegetable than 
the animal life. 
During hibernation, the respiration ceases almost wholly, and if it takes place at all, is 
so slight as to defy investigation. The air in which these creatures pass the winter seems 
to undergo no change by the breath, as would be the case if only one inspiration were 
made ; and, strangest of all, the animal seems capable of existing for some time in gases 
that would be immediately fatal to it in the waking state, or even without any air at all. 
The temperature, too, sinks to that of the surrounding atmosphere, although as a general 
