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THE POPULAR SCIENCE MONTHLY. 



that of natural history, gives that power of 

 accurate deduction which is invaluable in 

 the pursuit of every branch of knowledge. 

 We all know, I may add, how much has 

 been done in the researches of our time by 

 applying the principle of comparison com- 

 parison, for example, of the structure of 

 living bodies as the basis of modern biolo- 

 gy, the comparison of the structures of lan- 

 guages as the basis of philology. Depend 

 upon it, then, that the observation and anal- 

 ogy which natural history is continually 

 suggesting, as it is valuable for the purposes 

 of science, so it has a lighter but a most 

 graceful and civilizing use in supplying 

 those analogies taken from the seen world 

 and applicable to the unseen, assisting in 

 giving to every work of the mind that grace 

 and beauty which is just as appropriate and 

 desirable, though it may not be so indis- 

 pensable to it, as are the higher qualities of 

 solidity and truth." 



How the " Goat-Snckers " came by their 



Kame. Mr. A. R. Wallace calls attention to 

 an interesting observation made by Charles 

 Waterton, which throws some light on the 

 origin of one of the superstitions of natural 

 history. Ever since the time of Aristotle, 

 at least, the belief has prevailed that the 

 bird known as the " goat-sucker "( Capri- 

 mulgus) actually sucks goats or cows. Ac- 

 cording to Pliny, the goat-sucker " enters 

 the fold and flies to the udders of the goats 

 in order to suck the milk." The fact that 

 the birds "fly to the udders" of the ani- 

 mals is confirmed by Waterton, but at the 

 same time he shows how erroneous is the 

 inference that they suck the milk. "lam 

 fully persuaded," writes that ingenious ob- 

 server, "that these innocent little birds 

 never suck the herds, for when they ap- 

 proach them, and jump up at their udders, 

 it is to catch the flies and insects there. 

 When the moon shone bright I would fre- 

 quently go and stand within three yards of 

 a cow, and distinctly see the caprimulgus cedeh 

 the flies on its udder." In another place he 

 writes : " When the moon shines bright you 

 may have a fair opportunity of examining 

 the goat-sucker. You will see it close by 

 the cows, goats, and sheep, jumping up ev- 

 ery now and then under their bellies. Ap- 

 proach a little nearer see how the noc- 



turnal flies are tormenting the herd, and 

 with what dexterity he springs up and 

 catches them, as fast as they alight on the 

 belly, legs, and udders of the animals. Ob- 

 serve how quiet they stand, and how sensi- 

 ble they seem of his good offices, for they 

 neither strike him nor hit him with their 

 tails, nor tread on him, nor try to drive him 

 away as an uncivil intruder." 



Geographical Distribution of Bats. At 



a meeting of the " Scientific Societies of the 

 Departments," lately held at Paris, a report 

 of which is given in " La Nature," Dr. 

 Trouessart, under the title of " Geographi- 

 cal Distribution of the Bats" {Cheiroptera), 

 read a paper, of which the following is a 

 summary: There are certain species of bats 

 which pass the winter in a state of torpor 

 in caverns or in abandoned quarries for 

 example, the horseshoe bat or in the hol- 

 lows of trees, under the roof-timbers of 

 houses, or in crannies in the walls as the 

 Pipistrella, so common in cities, which, 

 awakening during very mild winters, is 

 sometimes seen flitting about in January. 

 But it is an error to suppose that all bats 

 hibernate. Many Cheiroptera migrate after 

 the manner of birds, and this fact accounts 

 for the reduction of the number of species 

 from eight hundred to four hundred, as dis- 

 tinctions of species had been set up merely 

 on the ground of the great distance between 

 localities. Many species of bats seen in 

 France are migratory, and are found there 

 only in the summer months, having come in 

 pursuit of the insects on which they subsist. 

 Of twenty-five species occurring in Europe, 

 at least twenty-two are found also in east- 

 ern Asia. Bats possess considerable power 

 of flight. The flying fox (Pteropus rubricol- 

 lis) of the tropical parts of the Old World 

 can at one flight compass a distance of 

 thirty leagues. This vigorous power of 

 flight explains the presence of Cheiroptera 

 in Australia, where they are the only native 

 Monodelphs, as also in the islands of Poly- 

 nesia and in New Zealand, a country rich in 

 its avifauna, but which, with the exception 

 of several species of bats, possesses no mam- 

 mals save those purposely introduced by 

 man, and the rats and mice brought by 

 ships. Of the six families of the order 

 Cheiroptera, the Phyllostomata are cxclu- 



