B I 



126 



B I R 



there u a fleshy part called the cere. The lower ex- 

 tremities are protected above by a scaly skin, and the bottom 

 1 and toes b\ .1 c.ill.ius i.i .ii;':c.i!ion of the same 

 integument Soini', the turkey l<>r in-tanre, arc furnished 

 with h;iir iii ;uution. TUe ! > uilbalelv. 



i mi which ihe most iportive fancy cuuld create out 

 ul the feathery material, and every hue that the warmest 



:ialion could picture to iLself, will bo found among them. 



: a bird baa just left the egg iu covering is a downy 

 kind of hair, several little bundles taking their rise from one 

 common bulb. This is tbe origin of the future feather. A 

 dark cylinder goon makes its appearance, from the upper 

 extremity of which the sprouting feather emerges, while 

 the lower extremity receives the blood-vessels which supply 

 the vascular nourishing pulp of the barrel. When this 

 pulp has performed its office, and the stalk and other parts 

 of the feather are fully developed, it shrivels up into the 

 well-known substance which every one finds in a quill when 

 he cuts it for the purpose of making a pen. The care which 

 nature takes for the development of that particular part of 

 the plumage first which the wants of the particular bird 

 demand, should not be forgotten. A young partridge runs 

 oil' as soon as it is hatched to pick up the pupa) of the ant 

 (emmet's eggs as the gamekeepers eall them), which the 

 parent bird scratches up for it. Some time elapses before 

 it is necessary that it should fly ; we accordingly find that 

 the body froui the moment of its birth is protected with a 

 close-set downy covering, while all the strength i thrown 

 into the thighs, lens, bill, and neck. The wings are gra- 

 dually developed afterwards. A young thrush or a young 

 blackbird is hatched nearly naked, and while its body pre- 

 sents only a few scattered "bunches of weak downy hair-like 

 feathers, great progress may be observed in the formation 

 of the quills and other wing-feathers; because from the 

 habits of the bird it is necessary that it should be able to 

 fly as soon as it leaves the nest. 



As a general rule the plumage of the cock bird far ex- 

 ceed* in brilliancy that of the hen ; and in all such cases 

 the yoang, at first, put on the more sombre garb of the 

 mother. When the cock and hen are without much differ- 

 ence in this respect, the young have a particular distin- 

 guishing plumage of their own. 



Birds moult or shed their feathers. The summer dress 

 in many species varies from that of the winter. 



The mode in which the plumage changes is well de- 

 scribed in the Transactions of the Zoological Society by 

 Varrell ; and the same able zoologist has shown, in the 

 Philosophical Transactions, and in the Proceedings of the 

 Zoological Society, that the putting forth of the plumage of 

 the male hird is not c.mliucii to the lemale past the age 

 of reproduction (so many well-known instances of which 

 are given by Dr. Butter, John Hunter, and others), but 

 that the garb of the cock is assumed by those hen birds 

 which from malformation or disease are rendered unable to 

 in the continuation of the species. The following 

 three modes by which changes in the appearance of the 

 plumage of birds are produced have been pointed out by 

 Varrell: 1. By the feather itself becoming altered in 

 colour. 2. By the bird's obtaining a certain portion of new 

 feather* without shedding any of the old ones. 3. By an 

 entire or partial moult, in which the old feathers are thrown 

 off, and new ones produced in their places. The first two 

 of these changes are observed generally in the spring, indi- 

 cating the approach of tbe breeding season ; the third is 

 usually partial in the spring, and entire in the autumn. The 

 subjoined cut is explanatory of the situation of the principal 

 parts of the plumage, particularly those most conducive to 

 flight. 



That the (kin and integuments of birds perform the office 

 of emunctory organs appears not only by their moulting, 

 but also by the quantity of mealy dust separated from the 

 skin in many birds. The cockatoo, for instance, discharges 

 a quantity of white mealy dust from its akin, particularly at 

 pairing time, according to Blumenbach ; and Bruce, in the 

 appendix to his travels, gives an account of his shooting a 

 large bearded eagle, which, cm his taking it in his hands. 



ii him with a powder which was yellow on the breast, 

 where the feather* were of that colour, ami brown on the 

 back, where the plumage was of the same hue. A heron 

 too which be shot is described an having a great quantity 

 of blue powder on the breast ami ! 



The glands which secrete the oil n--d by birds in preening 

 and dressing their plutnago are situated on the upper part 



of the tail. Water-birds necessarily require a larger portion 

 of this protecting fluid, and accordingly we find the gland* 



1 in th.it race. Reaumur u: t in that \nnety 



of the common fowl which has no tail (tiuilu* fcumlutut), 



.lands are absent. '1 > ii ha* 



the glands situated not on the rump, hut farther lor. 

 Lawrence, in his translation of Blum -,itirt 



Ait<ilomy,*ay*, 'I have observed in the situation winch TNMJH 

 mentions a pretty considerable bag with hard rallou* 

 and nothing glandular in iu coatn. It contained a lir nwn 

 and unctuous but nearly solid matter, and I could di- 

 no external opening ; but it had been somewhat cut before 

 I examined it. It cannot, I think, be very well compared 

 with the oil-bag of the rump.' 



A. A, Primaries ; B,B, Tertwli; C. C, Uwei towrti ; I>. D. Grnlrr coverti , 

 !:. !:. Dastard wing; F, P, Soipulan ; G, Upper UU-covorU ; U, OMB ^il- 

 cuveru; I, 



Digestive Organs. 



Having endeavoured to give a sketch of the frame- 

 work of birds, of the means by which that frame-work is 

 set in motion, and of the integuments which cover the 

 external parts, we proceed to inquire into the provision 

 made for the support and nourishment of tho.-e annuals. 

 This provision, as might be expected, is, as Cuvier ob- 

 serves, ' in proportion to the activity of their life, and the 

 strength of their respiration.' First we have the bill, whose 

 horny covering in some degree answers the purpose of 

 teeth, and indeed it is in many instances notched so 

 represent them. The form of this important organ 

 infinitely, but with evidence of the most perfect do.-.: 

 each varied instance, according to the nature of the i 

 sary food. Thus in birds of prey it well executes the office 

 of a dissecting knife ; in seed-eating birds it forms a pair of 

 seed-crackers for extricating the kernel from the husk 

 which envelops it ; in the swallows and goatsuckers it is a 

 fly-trap; in the swans, geese, and ducks it is a flattened 

 strainer, well furnished with nerves in the inside for the, 

 detection of the food remaining after the water is strained 

 by that particular operation which every one must have 

 oi)served a common duck perform with its bill in muddy 

 water. In the storks and herons we find it a fish-spear : 

 and in the snipes and their allies it becomes a sensitive 

 probe, admirably adapted for penetrating boggy ground, 

 and giving notice of the presence of the latent worm or 

 animalcule. The food is transmitted from the bill through 

 the oesophagus into the stomach, which is composed of three 

 parts, viz. the crop, which is a dilatation of the (Esophagus 

 and lies just before the breast bone, the membranou* 

 stomach, {ventricule succenturii of the French), and the 

 gizzard. The first of these is furnished with many mucous 

 and salivary glands: in the next (and the structure of this 

 may be best observed in the gallinaceous birds) there are a 

 number of glandular bodies which pour out a copious secre- 

 tion to mingle with the food as it is ground down by tho 

 t'ul gizzard, which reaches its highest development in 

 granivorous birds. Thi* mill is rendered still more effective 

 by the swallowing of small hard stones by those birds with 

 their food, a practice which is clearly instinctive, and carried 

 sometimes to a great extent. In the museum of the Col- 



