HAKDWICKE'S SCIENCE-GOSSIP. 



127 



shoulders. Animals provided .with bushy tails are 

 all solitary in their method of living, so far as 

 I can find; and, therefore, an essential for their 

 survival is some method by which variations of tem- 

 perature shall be resisted. The use of the tail 

 for this purpose is, I think, best of all illustrated 

 in the great ant-eater (Myrmecophaga jubuta), in 

 which the hairs of the tail reach a very great size, 

 and cover up the animal when reposing, so that he 

 looks like a bundle of dried grass. It may also 

 serve as a protection by mimicry in this case. 

 Mr. Wallace states, also, that he uses bis tail as an 

 umbrella in a shower, and that the Indians divert 

 his attention from themselves by rustling the leaves 

 in imitation of a falling shower, and whilst he is 

 putting up his umbrella they kill him. Some of the 

 Myrmccophagaj have the lower end of the tail 

 naked, ar.d use it as a prehensile organ, whilst the 

 upper part remains covered with long hair, and is 

 used as a respirator. In other edentulous animals, 

 living in tropical countries, where they are not sub- 

 jected to extremes of temperature, the long hair is 

 replaced by scales, as in the pangolins, or the tail is 

 absent, as in the sloths. Amongst the rodents two 

 very curious contrasts in the matter of tail are pre- 

 sented by the guinea-pig and the squirrel. The former 

 is gregarious, and any one who has kept a hutch of 

 guinea-pigs must have seen how they protect them- 

 selves from loss of heat by packing themselves in 

 rows arranged heads and tails ; whilst the squirrel 

 is solitary, and in his nest, during his winter sleep, 

 coils himself up and covers his face with his tail. 

 The same is seen in the jerboa, and in the dor- 

 mouse during hibernation. Of the Carnivora, those 

 which have bushy tails are all solitary in their method 

 of living, though the wolf and jackal hunt in packs, 

 and those with the bushiest tails are most exposed 

 to low temperatures, as the Arctic fox and sable. 

 Of the Quadrumana the marmosets afford a striking 

 instance of a bushy tail as a probable provision for 

 protecting these delicate creatures from depressions 

 of their temperature. I have received an interesting 

 letter from Mr. Darwin on this point, in which he 

 says : — " Your view is new to me, and has only to 

 be suggested for its probability to be recognized. 

 I presume that of course you would thus account 

 only in part for the retention of a tail, and for its 

 modification. Your view does not preclude the con- 

 joint use of the tail for other service, as for gliding 

 through the air when flattened, as in the squirrel, or 

 as a signal to beasts of prey, in accordance with 

 Mr. Belt's ingenious suggestion in his ' Nicaraguan 

 Travels,' with respect to the great bushy and con- 

 spicuously-coloured tail ef the skunks. I wish we 

 knew the use of the extraordinary hairy tail of the 

 yak, which inhabits such cold regions, whether it 

 serves solely as a fly-flapper. If poor Dr. Falconer 

 had been alive, he could have told us." In reply I 

 said that I had missed the yak in my search for 



animals with bushy tails. But I find that he also 

 has a long additional fringe of hair nearly touching 

 the ground. When he lies down with his limbs 

 drawn up to, or under him, as all ruminants do, his 

 tail and fringe would act as a rug, preventing loss 

 of heat from the limbs and damage to them from 

 frost-bite — as the tissues outside the bone are thin, 

 and there is nothing but a rather weak circulation 

 to resist loss of heat. The yak lives close to the line 

 of perpetual snow, which is the condition in which 

 such epithelial appendages as he has would most 

 conduce to survival, and, therefore, that in which 

 they would be most easily evolved by natural selec- 

 tion. This seems to open out a curious study of the 

 mechanical arrangements which exist in animals for 

 the conservation of heat — a very important feature 

 in the struggle of life. Some forms of tails are yet 

 a puzzle, notably the tails of rats and mice, for which 

 I have as yet found no reasonable explanation. 



SKETCHES IN THE WEST OP IRELAND. 



Ciiaptek VII. — Aran pre-Christian 

 Antiquities. 



By G. H. Kinahan, M.R.I.A. 



THE Aran islands seem to have been inhabited 

 at a very early period, but the first-mentioned 

 authentic record is the advent of the Pirbolgs 

 chiefs, after their defeat in the battle of South 

 Moyturaby the De Danaan. These chieftains built 

 large duns or fortresses on the island, which are 

 now more or less destroyed. Of these forts the 

 principal is Dun dingus, on Inishmore, built, ac- 

 cording to O'Pflahertie, "about the birthtime of 

 Christ." Its founder was Engus M'Uathmore, 

 king of the Pirbolgs. It is situated on the edge 

 of the cliffs (279 feet high) half a mile south-west 

 of Kilmurvy. On the laud side is a thick high 

 rampart, constructed of flaggy limestone without 

 mortar, while outside the rampart was a chevaux- 

 defrise of long stones planted on end, similar to 

 the one previously mentioned in Chapter V., as sur- 

 rounding the caher near Corrofin, in the Burren. 

 This dun or caher is in a very ruinous condition, 

 and yearly it is becoming more dilapidated, it being 

 principally destroyed by persons hunting after 

 rabbits. One of the forts in best preservation is 

 Dunonaght, in the western portion of the island : the 

 name of its founder seems to be lost. Others are 

 Dunoghil, a little south of the village of the same 

 name, and about half a mile on the west of the last 

 is the ruin of a large oval caher called McDoon, 

 which by tradition is supposed to have been the 

 strongest fort on the island. In the vicinity of 

 these forts are the ruins or sites of two or three 

 small cahers, the doorway of one of them being 

 figured in Chapter V. These, however, are supposed 



