THE EDINBURGH 



JOUENAL OF NATUEAL HI 



AND OF 



THE PHYSICAL SCIENCES. 



N^7. 



SATURDAY, JANUARY 16, 1836. 



ZOOLOGY. 



DESCRIPTION OF THE PLATE — CAMELS. 



The only two animals -vvhicli constitute this genus are in general so mild and inoiTcn- 

 sive in their disposition, that they prove extensively serviceable to mankind in those 

 hot and sandy regions, where they arc employed as beasts of burthen. Their pace 

 is usually slow; but being abb to sustain themselves, even on the longest journeys, 

 with a very small portion of food, and but little water, they undergo fatigues which 

 few, perhaps no other animals, could endure. 



Their hair is a valuable article of commerce, and their flesh forms a palatable food. 



Like all the other genera of the ruminating order, they are provided with four 

 stomachs, in consequence of which they not only live solely on vegetable food, but 

 ruminate or chew the cud. The food, after being swallowed without undergoing the 

 process of mastication, is received into the first stomach, where it remains for some 

 time to macerate; and afterwards, when the animal is at rest, by a peculiar action of 

 the muscles, it is returned to the mouth in small quantities, chewed more fuUv, and 

 then swallowed a second time for digestion. 



Fig. 1. The Bactrian Camel (Camelus liacirianusy Linn.) — This animal is at 

 once distinguished from its congener the Dromedary, by having two haunches, one of 

 which is situate on its shoulders, and the other at a little distance behind. It is a 

 considerably-larger animal than the other ; its legs are proportionally shorter, wliile 

 the body is longer. An animal of this species, which was exhibited in London in 

 i829, measured eight feet from the part of the back between the humps to the 

 ground. 



Its original country is supposed to be the ancient Bactriana, now called Turkestan. 

 The species has been spread over Persia, Thibet, and China. It is, however, rarely 

 to be met with except in the great middle zone of Asia, to the north of Taurus, and 

 the great Himalaya range of mountains. It is capable of bearing a much colder and 

 more moist climate than the Arabian species. The Camel has been known to exist 

 in the neighbourhood of Lake Baikal, in Siberia, where its only food, dm-ing winter, 

 was the bark and tender branches of the birch. 



The Camel Hves to a great age. One which was kept in the Menagerie of the 

 Jardm des Plantes at Paris was supposed to be nearly fifty years old when it died. 

 The food of this animal is hay or lucern, of which it consumes about thirty pounds 

 a day; while a draught of six gallons of water will suffice for some days. 



Fig. 2. The Dromedary (Camelus Dromedarius^ Linn.) — The Arabian Camel 

 or Dromedary has but one haunch, situate on the middle of the back. Its height at 

 the shoulder varies from five to seven feet. Its hair, which is soft, woolly, and un- 

 equal, is longer on the nape of the neck, throat, and hamich, than on any other parts 

 of the body ; it is of a pale reddish-fawn colour. 



The feet of both the Camel and Dromedary are very singular productions of Nature, 

 being admirably fitted for treading on a smooth or soft surface. They are divided 

 into two toes not separate, each covered with a broad nail; and thus the feet are 

 intermediate between the hoofs of a horse and cloven feet. From the heel forwards, 

 they are protected by a horny sole, uniting the middle part, and leaving the 

 toes free. This sole is part of an elastic substance, which, being bedded in two cavi- 

 ties of the foot, yields to the pressure of the soil; whilst the toes spread open, touch- 

 ing the ground, in the same way as the foot of the Rein-Deer extends itself to pre- 

 sent a large surface to the snow. By this formation, the Camel is prevented from 

 sinking into the soft sand of the desert tracts, which it is so frequently obhged to 



Ants. — Colonel Sykes relates an anecdote with regard to an Indian species of Ant, 

 which he calls the Large Black Ant, instancing, in a wonderful manner, their per- 

 severance in attaining a favourite object. This was witnessed by himself, his lady, and 

 his whole household. When resident at Poonah, the dessert, consisting of fi-uits, 

 cakes, and various preserves, always remained upon a small side table, in a veran- 

 dah of the dining-room. To guard against inroads, the legs of the table were 

 immersed in four basins filled with water, it was removed an inch from ths v,-all, and, 

 to keep off dust through open windows, was covered with a table-cloth. At first the 

 ants did not attempt to cross the water, but as the strait was very narrow, from an 

 inch to an inch and a half, and the sweets were very tempting, they appear at length 

 to have braved all risks, to liave committed themselves to the deep, to have scrambled 

 across the channel, and to have reached the object of their desires, for hundreds were 

 found every morning revelling in enjoyment. Daily vengeance was executed upon them 

 without lessening their numbers; at last, the legs of the table were painted, just 

 above the water, with a circle of turpentine. This at first seemed to prove an effec- 

 tual barrier, and for some days the sweets were unmolested, after which, they were 

 again attacked by these resolute plunderers; but how they got at them seemed totally 



unaccountable, till Colonel Sykes, who often passed the table, was surprised to see an 

 ant drop from the wall, about a foot above the table, upon the cloth that covered it; 

 another, and another succeeded. So that though the turpentine and the distance 

 from the wall appeared effectual barriers, still the resources of the animal, when 

 determined to carry its point, were not exhausted, and by ascending the wall to a 

 certain height, with a slight effort against it, in falUng managed to land in safety upon 

 the table. 



ON THE TAIL-GLAND IN BIRDS BY M. REAUMDil. 



" Were I tempted to explain why the hinder part of the hens without tails has not a 

 secretion performed in it Uke that which is observed in other hens and in other kinds 

 of birds — were I tempted, I say, to explain it, I should be aware of the danger of 

 the possibility of committing mistakes, by the very obligation I think myself under of 

 exposing, as an error, the notion which naturalists and philosophers have framed 

 to themselves concerning the utility of the unctuous liquor that issues from the 

 canals in the tail of birds. All the works of Nature being lavishly filled with won- 

 drous characteristics, fit to raise in us a most just admiration of those who, from tho 

 best intentions, expose them to our eyes, in order to force us to acknowledge the 

 Author, of them, are, on account of the multitude of those wonders, hable to 

 some reproach, when they happen to mention among them some that arc not of tho 

 utmost certainty. They all have been of opinion, that the feathers of birds, in order 

 to be sheltered against rain, wanted to be done over with a kind of oil or grease, that 

 might cause the water to run off them without penetrating, and that this unction 

 wanted to be repeated from time to time. I have elsewhere proved, in a memoir on 

 feathers, that they have been wrong to entertain that notion. In consequence of it, 

 they have pretended to make us admire a reservoir of unctuous matter placed in the 

 hinder part of each bird, out of which he expresses, and takes it, with the end of his 

 bill, to convey and spread it all over the feathers that want it. 



" I shall not undertake to show here how little the quantity of matter that may be 

 daily supplied by this reservoir is in proportion to the extent of the surfaces resulting 

 from the assemblage of the numberless feathers with which a hen or a duck is covered, 

 nor how long a time would be necessary to enable the reservoir to supply a quantity 

 of tho said matter, sufficient to besmear the surface of only one of those feathers. 

 In order to explode a notion that must needs have been pleasing, since it was univer- 

 sally espoused, I need only say that the feathers of our tail-less, or, as I call them, 

 rump-less hens, are as much proof against rain as those of other hens, and of many 

 other birds that are provided with that part in which the secretion of an unctuous 

 matter is made. It is, however, a fact that birds are sometimes seen pecking this 

 part of their body ; and this circumstance has been considered by the observers as 

 conclusive evidence that they squeezed, from their tail-gland, the unctuous matter 

 which was afterwards to be applied to their plumage ; and in this hasty conclusion 

 they forgot that the bill of the bird was insufficient to convey as much unctuous mat- 

 ter as was necessary to besmear their entire plumage, and render it greasy. A more 

 natural idea would have been to suppose, that the bird pressed this reservoir or extra- 

 ordinary canal to relieve an irritation of the skin, caused, in all probability, by the 

 matter becoming too thick to flow, in its usual manner, through so small an orifice. 

 Even school-boys are aware that an obstruction in this vessel occasionally takes place, 

 and produces sickness in the birds; for their sparrows look poorly and droop when so 

 afflicted, and almost the first thing they do, is to examine the state of the tail-gland; and 

 when they think that it presents an unusually swelled appearance they press it, and 

 even sometimes prick it \nth a needle, to allo%7 the thickened matter to escape, so as to 

 force it out. I do not know whether this operation is always attended with complete 

 success, but I would conceive it better to endeavour to cure this obstruction in the 

 excretory canal, produced by the inspissated unction, to moisten, or introduce into it 

 some small solid body. So long as we remain in uncertainty why a secretion of a 

 certain matter takes place in our ears, though in a very small quantity, we shall not 

 think it incumbent ou us to account for, how the secretion of a particidar matter is 

 effected in the tail-glands of birds." 



In narrating the diseases of Birds, Dr Bechstein remarks, that " this gland, which 

 contains the oil necessary for anointing the feathers, sometimes becomes hai'd and in- 

 flamed, and an abscess forms there. In this case the bird frequently pierces it itself. 

 It may be softened by applying fresh butter without any salt; but it is better to use 

 an ointment made of white lead, litharge, wax, and ohve oil. The general method 

 is to pierce or cut the hardened gland; but if this operation remove the obstruc- 

 tion, it also destroys the gland, aud the bird will die in the next moulting for want of 

 oil to soften the feathers." 



MTien the gland is obstructed, the feathers which surround it are ruffled, and the 

 bird is constantly pecking and adjusting them, and instead of being of a yellow, 

 which is its natural colour, it becomes brown. This complaint is extremely rare 



