758 



H I R U N D O. 



the great attraction for it is the house-fly, for that fly 

 is found only in the neighbourhood of houses, and i 

 rare, indeed, even in those wild woods where wingec 

 insects abound the most. It is astonishing to what 

 an extent so small a creature as this house-fly plays 

 the scavenger, and reproves, by the countless swarm 

 in which it appears in houses toward the latter part 

 of the year, the slovenliness of those to whom the 

 charge of such houses is committed. The house- 

 martin is not quite so dashing a bird as the chimney- 

 swallow ; its wings are rather shorter and less pointed, 

 and the external feathers of its tail are not so much 

 produced. Still the house-martin is the prettiest bird 

 of the two, and its familiarity makes it an especial 

 favourite. The whole of the upper part, with the 

 exception of the rump, is black, brownish-black on the 

 tail-feathers and the quills and coverts of the wings, 

 and bluish-black on the rest of the body. All the 

 under part is white, of a very pure tint, and the feathers 

 on the sides of the neck break finely into each other. 

 The chief difference between the sexes is, that the 

 breast of the female has a slight greyish tinge, while 

 that of the male is pure white. The tarsi and toes 

 are covered with whitish down, but in no very great 

 quantity. 





Martin. 



The house-martin is not only the most familiar of 

 our swallows, but it is also the first to reach us in the 

 epring, and the last to leave us in the autumn. As 

 the whole race comes from southern climates, return- 

 ing to those climates again when the season which is 

 favourable to their habits in our country is over, they 

 appear first and last in the more southerly places ; 

 but still they are not long in distributing themselves 

 over the country ; and it is highly probable that 

 the greater number of them frequent the same breed- 

 ing-places for a number of years. If they can build 

 .under a projection, which will keep the rain out of 

 their nests, they prefer such a situation ; but if not, 

 then they construct a dome to the nest. Those nests 

 are often in curious places. White mentions one 

 which was built in the wing of an owl which had 

 been nailed to a barn ; and Jesse mentions one which 

 had not only constructed its nest, but performed its 

 incubations and reared its brood, on the knocker of 

 the hall-door at a gentleman's house in Warwickshire. 

 When the door was opened the bird quitted the nest 



for a little, but returned when the door was closed. 

 The winning ways of house-martins, their attention 

 to each other and to their young, and their neat ap- 

 pearance, all tend to render them great favourites ; 

 and we believe that, in those parts of the country 

 where there is any feeling of nature among the 

 people, the schoolboys would be considered as acting 

 as sacrilegious a part, in destroying the nest of a 

 house-martin, as in plundering that of a sky-lark, 

 whose glorious matin-song charms even the rustic into 

 feelings of respect and gratitude. 



The structure of this swallow's nest is well known. 

 It is formed of mud worked with moisture, much in 

 the same way as the mud walls of cottages in some 

 countries, or as that combination of mould which engi- 

 neers use for " puddling," or rendering water-tight 

 the banks and bottoms of canals in porous soils. This 

 structure being usually formed in the dry and warm wea- 

 ther, and applied in small quantities, so that each layer 

 consolidates before a fresh one is applied ; the texture 

 is very firm and compact, and very nearly impene- 

 trable by water, and insoluble in it. This is also the 

 character of those walls which are constructed wholly 

 of loam or mould, in the manner which is called 

 building en pise in some parts of France ; for these are 

 more dry and durable than walls of stone or brick. 



Some have alleged that there are certain glands in 

 the stomach of those swallows which build compact 

 nests, either of mud, as is done by the species under 

 consideration, or of gelatinous matter, as is done by 

 some others hereafter to be described, which secrete 

 a glutinous substance that assists in giving firmness 

 to the nest ; but the nests of common swallows do not 

 ontain a trace of any such matter in their compo- 

 sition; and it is very improbable that there is any 

 such matter furnished by the stomachs of those species 

 which construct the gelatinous nests. It is true that 

 we are not very well informed as to what the sub- 

 stance is of which those nests are constructed ; and it 

 s also true that there are peculiar glands in the 

 stomachs of those swallows, of which, owing to our 

 gnorance of the general habits of the birds, we do 

 not know the use ; but though we are ignorant of the 

 articular matter of which the nests are formed, and 

 dlso of the particular uses of those glands, it is not a 

 ery philosophical proceeding to apply our ignorance 

 of one matter as an explanation of our ignorance of 

 another ; and yet this has often been resorted to and 

 >een exulted in as something of no common scientific 

 depth by men of high name in comparative anatomy 

 and animal physiology. 



The safest way of avoiding such blunders as these, 

 or if they deserve a gentler epithet, such per saltum 

 onclusions, which fairly leap across the durk place 

 without throwing any light upon it, is to have recourse 

 ;o the general analogy of nature, and see whether 

 hat would be violated by our supposed discovery, 

 ^ow we are not aware that there is any warm-blooded 

 animal which elaborates any substance in glands or 

 any other apparatus in the stomach, for any purpose 

 saving the preparation of food either for itself or for 

 ts young ; which last is understood to be, in part at 

 east, the case with the stomachs of pigeons ; nor is 

 t in warm-blooded animals only that we find the 

 stomach confined to the single function of nutrition ; 

 or in those invertebrated animals which elaborate 

 shells, and spin threads, and weave webs, and form so 

 many other curious structures, we always find that 

 there is a distinct and specific structure, or apparatus 



