H I RU 



in the animal, specially adapted for this purpose, and ' 

 having nothing to do with its digestive system ; but 

 requiring a process of secretion in addition to that of 

 assimilation. We mention this circumstance in order 

 to caution the reader against being carried away by 

 that analogy of double ignorance, which is more 

 frequently a stumbling-block than many would be apt 

 to suppose. That we are equally ignorant of two 

 subjects constitutes a certain sort of resemblance 

 between them in our apprehension, but it is not a 

 resemblance from which any conclusion can be drawn. 

 House-martins are very industrious little creatures ; 

 and in those parts of the country which are best 

 adapted to them, they are understood to rear three 

 broods in the course of the season ; one in May, a 

 second in June, and a third in July. The hatches do 

 not exceed four or five in number, and each incuba- 

 tion lasts about fifteen days. In the intervals the 

 house-sparrows sometimes take possession of the mar- 

 tins' nests ; and though the martins are unable to 

 expel the intruders, it is said that they sometimes 

 build them in. 



THE SAND MARTIN (H. riparia.} Is the smallest 

 of our British swallows ; and it is snorter in the wings 

 and less dark in the colour than those which have 

 been mentioned. Its style of flight is probably as 

 continuous as that of any of the others, if we except 

 the swift, but it is not so bold or discursive. The 

 sand-martin, or bank-swallow as it is called, is brown- 

 ish black on the upper part and the breast, but white 

 on the remainder of the lower part, and also on the 

 chin and upper neck ; upon which latter the white 

 forms a collar nearly halfway round. 



This species arrives at least as early as any of the 

 others, and is as late in quitting the country ; but it 

 differs from them in the places to which it resorts, and 

 also in its habits. It does not necessarily come near 

 the abodes of men, though if such ground is suitable 

 for its purpose, it is by no means a timid bird ; and it 

 is by no means uncommon to find the house-martin 

 very abundantly all over a village, and the sand-mar- 

 tin as plentiful in the sides of a steep bank at the 

 entrance of the village. 



In constructing of their nests, sand-martins are 

 excavators, not builders ; and they choose the bold 

 and abrupt faces of banks, where the soil is dry and 

 not over-hard, but where it is not likely to be de- 

 composed or washed away by the rain. Firm sand 

 appears to suit them better than any thing else ; and 

 where a road has been cut to a considerable depth 

 through a sandy knoll, martins generally find it out 

 and drill it in holes for their nests. Such places are 

 also in general warm, and abound with flies, so that 

 the birds have plenty of food ; but under equal cir- 

 cumstances, they prefer the vicinity of water, over 

 the surface of which they are very industrious. 



When a colony first take possession of a new bank 

 which has been opened to them, the scene is a busy 

 and far from an uninteresting one. They attack it 

 with mattock and shovel, the bill answering for the 

 first and the claws for the last. The pair work inces- 

 santly at this excavation ; but as the entrance is not 

 larger than to admit one bird, they do not work m 

 company but by turns, the one carrying on the exca- 

 vation while the other is feeding. As they labour 

 hard, and live upon small prey which they catch on 

 the wing, their life is a busy one. But still the alter- 

 nation of digging and feeding appears to afford them 

 considerable relief, as different parts of the body come 



N D O. 759 



into their most severe action during the two tasks. 

 The excavation for the nest is often made to a con- 

 siderable depth into the bank ; and, as is the case with 

 all birds which mine into deep banks, the entrance is 

 made sloping upwards, so as to render the entrance 

 of wet impossible. After the birds have excavated 

 these nesting places to the necessary depth, they 

 line the interior with vegetable fibres and feathers ; 

 but as they have more natural shelter from the depth 

 of the excavation, which is often as much as three 

 feet, they are not so careful in lining the nest as those 

 species are which breed in more open places. The 

 eggs are rather more numerous than those of the 

 house-martin ; but it is probable that the incubation 

 lasts longer; and it is certain that the birds take 

 more time before they are fledged ; and there are not 

 so many broods in the year. The young birds have 

 rust-coloured margins to the feathers on the upper 

 part ; and in this marking, the female is intermediate 

 between the young and the male. 



Of the hirund'mes which we have now mentioned, 

 the martins are perhaps the most characteristic as 

 British birds; and they are probably more exclusively 

 birds of that migration which takes place between 

 Europe and Africa, nearly in the line of the meridian, 

 than any others of the genus ; for though birds ot 

 this genus are found in almost every part of the world, 

 north or south, most of them have more the character 

 of our swallows than of our martins. These foreign 

 species are so numerous, their habits are so little 

 known, and those which are known, in general agree 

 so closely with those of the species with which we 

 are familiar, that we must confine ourselves to mere 

 notices of a few of the more remarkable ; and before 

 we do so we shall advert to the swifts, as British birds, 

 which, though very closely resembling the swallows 

 and martins in their general habits, have sometimes 

 been arranged and described as a separate genus 

 under the name Cypselus. 



THE COMMON SWIFT (C. apus). Though not alto- 

 gether footless, as the epithet apus would lead us to 

 suppose, is yet worse supplied in feet available to any 

 purposes of locomotion, than perhaps any other 

 British bird. It is true that some of the aquatic birds 

 are as ill adapted for walking as the swift is ; V\it then 

 their feet are all swimming feet, and thus adapied for 

 motion of another kind, and the reason of their an- 

 swering so ill for the common purpose of walking is 

 chiefly or entirely their superior adaptation to that of 

 swimming. The swift, on the other hand, is no 

 swimmer, and though it partakes in so far of the habit 

 of the race generally as to be able to strike the sur- 

 face of the water as it darts along on the win?, yet 

 even this habit is not nearly so strong in it as in the 

 swallows properly so called. The foot of the swiit 

 is remarkably short, with all the toes turned forwards, 

 and the tips 'of the claws directed toward the centre 

 of the foot ; it is thus a perching foot, but it is adapted 

 for sticking to the asperities of upright rocks and 

 walls, in which the bird is greatly assisted by the 

 , great length of the wings and the tail, and the pecu- 

 ! liar structure of each, which consist of very fine fea- 

 thers successively overlapping each other, so as to 

 give great stiffness to the part, at the same time that 

 it is comparatively light. 



Of all our birds, the swift may be said to be the 

 i most lofty inhabitant of the sky, and the one which is 

 1 most constantly upon the wing, and its structure cor- 

 : responds with this habit, for our swift is our best 



