106 



THE EDINBURGH JOURNAL OF NATURAL HISTORY, 



curves, or stops in the midst of its full career, is less astonishing than it ought to be, 

 familiarity in this, as in other instances, pr'iducing a disposition to regard as simple 

 what is the result of elaborate mechanism. 



It continues searchinfj the air in this manner all day long, when the weather is 

 good; nor does a shower, however heavy, usually induce it to relinquish its pursuit. 

 Even in the midst of heavy thunder-rains, it may often be seen wheeling and diving 

 with unremitted vigour, and in drizzly weather, when the swallows have disappeared, 

 it pursues its avocations, heedless of the damps. On the day on which the accession 

 of her Majesty was proclaimed in Edinburgh, the weather was extremely sultry and 

 oppressive, and a very heavy i ain fell in the afternoon, during which I w^as a little 

 surprised to see the Swifts wheeling joyously over the town at a considerable height. 

 How the insects, of which they were in pursuit, could exist in such a rain, is not less 

 astonishing. In dry and sunny weather, however, it generally rests in the middle of 

 the day, and towards evening is extremely active, filling the air with its shrill and 

 joyous screams. 



Its food consists entirely of insects, which it seizes exclusively on wing. Several 

 curious circumstances may be noted with reference to its pursuit of these animals. 

 In rainy or damp coldish weather, the Swifts are to be found flying, at no great 

 height, generally from ten to fifty or sixty yards, frequently in bands of twenty or 

 more, often shooting along the sides of the hedges, descending in curves, and skim- 

 ming the surface of the grass, wheeling, circling, and perfoi'ming all sorts of evolu- 

 tions. On such occasions, they ai'e easily shot, for they often come quite close to 

 the gunner, being altogether heedless of his presence, so intent are they on capturing 

 their prey. 



In fine weather, they fly low in the mornings and evenings, and are among the 

 first birds that come abroad, and the latest in retiring to their places of repose ; but 

 during the greater part of the day they are to be seen chiefly at a great elevation, 

 apparently that of several hundred yards. Yet I have seen them flying high in rainy 

 weather, when the clouds w^ere separated by long intervals ; and, from long observa- 

 tion, I am satisfied that no prognostication of the weather can be based on the flight 

 of Swifts and Swallows. These birds fly high or low, according as their prey is 

 abundant in the higher parts of the air, or near the surface of the ground or woods ; 

 and as insects fly lower in the evening and morning, or in damp weather, so the Swifts 

 then descend. 



In dry sunny weather they frequently utter a long loud shrill scream, as they pur- 

 sue their prey ; but not in such weather only, for you often hear it before or during 

 rain, especially in the evening. Some have fancied this scream to be an intimation 

 given by the male to his mate that he is at hand, and others that it is caused by the 

 excitement of electricity; but these conjectures are destitute alike of ingenuity and 

 truth. It is not in thundery weather alone that Swifts scream, but often in the 

 clear, dry, and sunny skies, that exhibit no phenomena indicative of a want of elec- 

 tric equilibrium. And, as to the other theory, it sufflces to reflect that Swifts scream 

 as frequently over the open fields, at the distance of a mile or more from their resting 

 places, as when wheeling near steeples or towers. The cry of Jackals, Wolves, and 

 Hounds, when in full chase, seems to be analogous to the scream of Swifts under 

 similar circumstances, but the cause and use of either is not satisfactorily ascertained. 

 I have observed, however, that single birds very seldom scream, and that the loudest 

 and most frequent cries are heard when birds are evidently in active and successful 

 pursuit. It is so with Terns, Gulls, and even Gannets; and when you see these 

 birds hovering over the sea, and hear their mingling cries, you may be sure that they 

 have discovered a shoal of fishes, and are enjoying their good fortune. They seem 

 to scream or cry out from pleasure, and thus give intimation to their fellows of the 

 plentiful existence of food. As to the organ of this loud and shrill scream in the 

 Swift, namely, the trachea, it is short, remarkably flattened, and gradually diminishes 

 in diameter to the bifurcation. It has no song or twitter, like the Swallows. 



If we suppose that the Swift is destined to feed exclusively on insects as they 

 flutter in air, which is in fact the case, we can be at no loss to trace the reason of its 

 peculiar form. Its body is light, but moderately stout, and its pectoral muscles are 

 large, otherwise it could not move its wings with the requisite strength and rapidity. 

 The wings are extremely elongated and narrow, because great rapidity of flight is 

 required in the pursuit of animals which themselves fly with speed, and because sud- 

 den turns require to be executed in seizing them. A short, broad, concave wing, as 

 that of a Partridge, on being rapidly moved, produces considerable velocity, but is 

 not fitted for either buoyant gliding or quick evolution. For the latter, the surface 

 of the wing must be extended in length and narrowed, and instead of presenting a 

 concavity, must be straight in the horizontal direction. Accordingly, in the Swift, 

 the wing has its humeral articulation peculiarly free, insomuch that, holding one alive 

 in your hand, you at first imagine that its wings have been broken. At the same 

 time, their muscular apparatus is remarkably strong. Then the secondary quills are 

 very short, and the primaries gradually and rapidly elongated, and furnished with very 

 strong, but highly elastic shafts. The tail, although not so long, is similarly con- 

 structed, being deeply forked, and so in a manner divided into two pointed and 

 elongated larainEe, similar in some degree to the wings, and aiding their action in 

 executing turns. In seizing its prey, while ghding or fluttering in the air, the bird 

 would be incommoded by any length of neck ; that part is, therefore, extremely 

 abbreviated, so that the head seems as if stuck upon the shoulders, as is the case, for 

 a similar reason, in the Cetacea and fishes. A long pointed bill would be of use ony 

 to a bird that has objects to pick from the ground or any other surface, or from 

 among soil or foliage. In the present case, the bird, carried with rapidity to its 

 tiny prey, merely requires to open its mouth, which is extremely enlarged, and sup- 

 plied with an abundant viscid secretion, which immediately entangles the fly that has 

 been caught, and prevents its escape, should the mouth be opened the next instant. 

 A bird so living has no need of walking, and there being nothing superfluous in na- 

 ture, its feet are reduced to cramping organs, by which it can cling to any kind of 

 surface when entering its nest, and its gait is merely a hobbling motion, aided hy 

 the winfs. It cannot rise from a flat surface, as I have ascertained by experiment, 

 but it liiunches from any little eminence, and if it can spring out horizontally is en- 



abled to fly ofl', although its usual mode of launching is, like that of the Gannet, by 

 a deep curve. 



These two birds are very similar in some points of their organization. Their 

 wings are long and narrow, and their flight is rapid and buoyant ; they seize their 

 prey by throwing themselves with velocity upon it; they launch from the rocks in 

 the same manner; and exhibit other points of mutual resemblance; as do the Terns 

 more especially, which, on account of their form and buoyant flight, have received 

 the vulgar appellation of Sea Swallows. 



The want of walking feet might be supposed to be somewhat inconvenient on 

 many occasions. Thus, when the bird has its nest to make, it must gather straws 

 and feathers ; but so great is its dexterity on wing, that it picks them up with ease 

 as it sweeps along. The nest is placed in the crevice of a wall or rock, in a steeple 

 or tower, in holes under the eaves, or in some such place, at as great a height as pos- 

 sible, and is composed of twigs, straws, and feathers, being bulky, but shallow, and 

 not neatly arranged. The eggs are two or three, of an elongated form, pure white, 

 their average length one inch, their greatest breadth seven and a half twelfths. 

 They are deposited from the beginning to the middle of June, and the young are 

 abroad by the end of July. Only one brood is reared in the season. The Swifts 

 take their departure from the middle to the end of August, thus residing with us 

 only three months and a half. 



As the insects on which they Hve are generally very small, they do not swallow 

 each as it is caught, but collect a number previously to the act of deglutition, for at 

 whatever period they are shot, one generally finds insects in their mouth. When 

 collecting food for their young, they do not return to the nest so frequently as the 

 Swallows, but accumulate a considerable quantity at a time. I have never found any 

 particles of gravel or sand in their gizzards, of which ihe hard cuticuliir lining is of a 

 reddish-brown colour, as in most birds that feed on insects, such as Wagtails, Pipits, 

 and Warblers. The insects on which they feed are numerous species of Coleoptera, 

 Ephemerae, Phryganeae, and occasionally LibellulEe and Muscae. 



It has been conjectured by some that the viscous saliva of the Swallows is used for 

 agglutinating the pellets of which the outer crust of their nests is composed. I have 

 carefully examined these mud crusts of the Chimney and Window Swallows, and can 

 find in them no appearance of cement. The Sand Swallow, which has no such crust 

 to its nest, has an equally copious viscid saliva. The same is the case with the Swift. 

 But the absurd fancies of ornithological writers are so numerous and so palpable, that 

 it is tiresome to refute them. 



The young Swifts are of a dusky colour, at first blind, and almost naked, having 

 merely a few straggling tufts of down. When fully fledged, they are of the same 

 colour as the adults, but of a lighter tint, with the edges of the feathers of the head 

 paler. 



Previous to their departure, the Swifts do not collect into large flocks, like the 

 Swallows, but disappear gradually, setting out apparently in small parties, in the same 

 manner as that in which they arrived. 



Mortality among Birds. — The following curious statement rests upon the 

 authority of a Lausanne Journal. During the last fortnight great numbers of sick 

 and dead Birds, particularly Thrushes, have been found in the fields of Soleure. An 

 inflammation of the spleen is the cause, and the disease is attributed to some acid 

 exhalations from the earth. All the Sparrows and Finches, it is added, have de- 

 serted the infected districts, and in several parts of Switzerland domestic animals 

 have been attacked in a similar way — Literary Gazette. 



BOTANY. 



Remarks on the Mountain- Ash, or Rowan, and the Apple Tree of Russia, ly 

 IVilliam Howison, M.D., Lecturer on Botany, Edinburgh. 



The Mountain-Ash, or Rowan (^Pyrus Aiicuparia), is distributed over tho 

 greater part of the Russian Empire, and towards the northern parts attains great 

 perfection, exhibiting a luxuriant display of blossoms and fruit. It occurs in abun- 

 dance on the outskirts of the forests, as also around noblemen's and gentlemen's parks 

 or policies, where the tree acquires great size. An open situation appears to be 

 absolutely necessary to its prosperity and increase ; for when found in the midst of 

 the forests, which, however, is rarely the case, it is always stunted, and falls into 

 the state of brushwood. In all parts of Russia where I have seen it, it is a natural 

 production, propagating itself by the seeds which are accidentally blown about, and 

 is very seldom artificially planted. During the summer and autumn, it enhan<-es the 

 beauty of the forests by its flowers and fruit, and on that account is esteemed by all 

 classes of Russians, as well as foreigners, in the neighbourhood of their habitations. 

 On the summer holidays or fasts, its branches in full flower are used to ornament the 

 windows of the village Isbac. In a country like Russia, where timber of the finest 

 kinds can be procured in such abundance, and at a trifling price, the wood of the 

 Mountain- Ash, on account of its softness and want of durability, is not applied to 

 any particular use. At times it presents itself amongst the billets of birch and fir J 

 sent down from the interior, when, of course, it is consumed along with them asl 

 firewood. This tree, however, is by no means destitute of value; for besides afFordJ 

 ino- food to man, it furnishes subsistence, during a considerable part of the year, id 

 the feathered inhabitants of the forests. 



The ripe fruit of the Mountain- Ash is used extensively, in a variety of ways, a^ 

 an article of food. The first application of it to this purpose, whi'-h I shall mentionJ 

 is to form a liquor, which is much esteemed as a stomachic, an agreeable bitter, an^ 

 for diffusing a dow over the system during the winter months. To make this, take" 

 a sm.all cask, two-thirds full of the ripe berries, picked and cleaned; fill it with 

 strono- spirits, and allow it to stand in a cold cellar for twelve months. Then run 

 off the spirit, which has become completely impregnated with the colour and flavour 

 of the fruit, and comes away perfectly pure, the macerated berries remaining at the 

 bottom. The spirit or tincture is then bottled. The boors or lower class make use 

 of the Watky, or common fermented spirits of the country, for the above purpose. 



