C93 



FALCONID^E. 



FALCONIDJ3. 



691 



feathers accurately numbered, and the mode of uniting the more 

 perfect feather to the injured stump is described in Sir John Sebright's 

 excellent observations on hawking. The reader who is disposed to 

 go farther back, will find in the ' Booke of Falconrie or Hawking,' &c. 

 ' heretofore published by George Turbervile, Gentleman,' (London, 

 email 4 to, 1611), the following chapters : " Of Accidents that happen 

 and light uppon a hawkes feathers, and first how to use the matter 

 when a feather cannot be ymped." " The way and manner how to 

 ympe a hawks feather, howsoever it be broken or bruised ; " and four 

 methods of operating, according to the circumstances, are detailed. 

 " How to ympe the traine of a hawke beeing all broken, and never a 

 feather whole or sound." Mr. Yarrell proceeds to observe that it is 

 difficult to estimate the comparative rapidity of flight in different 

 birds, and that our pigeons may appear to possess this advantage in 

 a degree little inferior to the true falcons ; but, he adds, the fact is 

 that these birds are deficient in natural courage, and are unable, 

 under circumstances, to avail themselves of those powers with which 

 they are gifted. 



" The bodies of all the species of true falcons when denuded of 

 their feathers are triangular in form, broad at the shoulders and 

 tapering gradually to the tail, the muscles of the thighs and legs of 

 great size ; but these characters are less prominent in the hawks, the 

 bodies of which are more lengthened, the legs long and slender, the 

 pectoral muscles smaller, the wing rounded in form, the fourth feather 

 the longest, the wing primaries broad in the middle, the inner webs 

 overlapping the feather next in succession, and emarginated towards 

 the end. These two divisions of the genus Falco, although the latter 

 are unequal to the former in powers, are remarkable for their bold 

 character and rapid flight, their invariable mode of striking their prey 

 on the wing, as well as the instinctive knowledge by which they are 

 directed to destroy life, attacking the most vital part, and penetrating 

 the bnin with their sharp hooked beak either by one of the orbits 

 where the bone is very thin or at the junction of the cervical vertebra; 

 with the occiput. 



"On comparing the bones of our two British eagles, the greater 

 power of flight appears to belong to the Albicilla, that of prehension 

 to the golden eagle, but both exhibit various indications of great 

 strength. 



" By an extended examination of the different species of buzzards 

 and harriers it will be found that the characters described as necessary 

 to produce rapid motion decline gradually. The sternum decreases 

 in size, the keel loses part of its depth, the clavicles and furcula 

 become more slight, while the form of the cranium, the loose ruffled 

 feathers of the neck, as well as the general downy texture of the 

 plumage, indicate the approach to the genus next in succession. Of 

 the bones of the different species of the genus Falco generally it may 

 be added that they are remarkable for their strength, such as are 

 cylindrical being furnished with numerous transverse bony processes 

 within the tubes, and the distribution of air throughout their internal 

 cavities. The humerus is supplied with air through several orifices 

 upon its inner and upper surface, and some difference will be found 

 in the angle at which this bone is articulated with the clavicle to 

 accomplish the ascending flight of the sky-lark, in contradistinction 

 to the precipitous horizontal direction of the falcons. The thigh bone 

 is also supplied with air by an orifice at the situation which answers 

 to the front of the great trochanter ; the large bones forming the 

 pelvis, the vertebrae, sternum, furcula, clavicles, scapuhe, and even 

 the ribs, are all furnished with apertures for the admission of air 

 supplied from the various cells of the abdomen, sides, and thorax. 

 This distribution of air to the bones does not seem however to be 

 absolutely necessary for flight, since the young birds of our summer 

 visitors appear to perform their first autumnal migration with perfect 

 ease and celerity, at an age when the cavities of their bones are filled 

 with marrow. 



"The various characters of the feet are too obvious to require 

 particular notice." (Yarrell.) 



In the Museum of the Royal College of Surgeons in London the 

 reader will find a preparation (Gallery, 522 A) of the stomach of the 

 Golden Eagle. It is laid open so as to show the orifices of the 

 numerous gastric glands of the proventriculus, the smooth lining 

 membrane of the gizzard, and the valvular structure of the pylorus. 

 The oesophagus is very wide, so that externally it appears to form one 

 Continued cavity with the proventriculus and stomach. John Hunter, 

 in his 'Observations on Digestion' ('Animal Economy'), says, " There 

 are few animals that do not eat flesh in some form or other, while 

 there are many who do not eat vegetables at all ; and therefore the 

 difficulty to make the herbivorous eat meat is not so great as to make 

 the carnivorous eat vegetables. Where there is an instinctive prin- 

 ciple in an animal, directing it either to the one species of food or the 

 other, the animal will certainly die rather than break through of its 

 own accord that natural law ; but it may be made to violate every 

 natural principle by artificial means. That the hawk tribe can be 

 made to feed upon bread I have known these thirty years ; for to a 

 tame kite I first gave fat, which it ate very readily, then tallow and 

 butter, and afterwards small balls of bread rolled in fat or butter, and 

 by decreasing the fat gradually it at last ate bread alone, and seemed 

 to thrive as well as when fed with meat This however produced a 

 difference in the consistence of the excrements ; for when it ate meat 



they were thin, and it had the power of throwing them to some 

 distance; but when it ate bread they became firmer in texture, and 

 dropped like the excrement of a common fowl. Spallanzani attempted 

 in vain to make an eagle eat bread by itself ; but by inclosing the 

 bread in meat, so as to deceive the eagle, the bread was swallowed 

 and digested in the stomach." 



Mr. Yarrell observes that the oesophagus offers nothing peculiar 

 beyond that of other birds not possessing the power of minutuly 

 dividing their food. It is plicated lengthways, allowing great exten- 

 sion, and its separation from the stomach is marked by a zone of 

 gastric rings. The same author notices an opportunity which 

 occurred to him of observing the castings or pellets of some eagles, 

 which had been occasionally fed with dead pigeons. These castings 

 showed that the vegetable food, such as peas, wheat, and barley, which 

 had been swallowed by the eagles in the crops of the pigeons, remained 

 entire, but somewhat enlarged and softened by heat and moisture. In 

 these cases no part of the bones remained. 



The intestines of the Falconidce are in general short and large, but 

 Mr. Yarrell remarks that the Osprey is an exception to this rule, and 

 that to the thin membranous stomach of this bird there is attached 

 an intestinal canal measuring 10 feet 8 inches in length, and in some 

 parts scarcely exceeding a crow-quill in size. The canal in most of 

 the species he adds, is in length, compared with that of the bird 

 itself, as three to one ; but in the Osprey it is as eight to one ; and he 

 observes that in the otter the intestinal canal is very long, equal in 

 size, and without csccal appendage ; the seal too has long intestines 

 with a small ciecum. Mr. Yarrell inquires therefore if it may not be 

 concluded that the small quantity of nutriment which fish, as an 

 article of food, is known to afford renders this extent of canal 

 I necessary in order that every portion may be extracted. The c;eea 

 of the Falconidce amount to no more than minute rudiments. 



In the organs of respiration there is nothing very remarkable 

 among the Falconidce. The trachea is composed of two membranes 

 inclosing between them numerous bony rings, forming a more or less 

 perfect tube. The rings are strong and compressed. The point of 

 divarication, the cross-bone, and bronchia; constituting together the 

 inferior larynx, are of the most common form, having but one pair of 

 muscles attached ; and the voice though powerful possesses, as might 

 be expected, but little variation. (Yarrell.) Falco mmicus seems 

 however to be an exception, and it would bo desirable to examine its 

 trachea for the purpose of ascertaining whether it is not organised 

 more after the fashion of that of the singing birds. 



It might be expected that in the Falconidce the soles of the feet and 

 lower surfaces of the toes which come so closely into contact with 

 the living prey would be endowed somewhat more largely with the 

 sense of touch than those of birds which have no such habits ; 

 accordingly we find in the Museum of the College of Surgeons 

 'Physiological Series) a preparation (No. 1400) of one of the feet of 

 an eagle, with the cuticle removed, showing the papilla; aud cushions 

 of the cutis on the under surface of the foot. 



In the same museum (No. 1482) will be found the tongue, larynx, 

 and lower jaw of the Golden Eagle (Aquila chiijsaetos). The tongue 

 is fleshy and large, divided into two lateral portions by a deep longi- 

 tudinal fulTow ; at its base is a series of small retroverted spines 

 arranged in the form of a chevron, between which and the larynx the 

 surface is studded with the orifices of numerous glandular follicles : 

 two rows of retroverted spines again occur behind the larynx. There 

 is a row of glandular follicles on either side of the framum lingua;, 

 and a large cluster of similar orifices immediately anterior to it. The 

 preparations Nos. 1483 and 1484 exhibit respectively the tongue and 

 fauces of an Erne (Haliceetus albicilla) and the tongue and larynx of 

 an Osprey (Pandion haliceetw). 



A longitudinal section of the anterior part of the head of the 

 Golden Eagle will be found in the same museum and series (No. 1538). 

 The preparation shows the turbinated cartilages and cavity of the 

 nose, together with part of the orbit and the air-cell continued from 

 it anteriorly and situated below the nose. The parts are minutely 

 injected, and the vascularity of the pituitary membrane covering the 

 middle turbinated cartilage is well displayed. No. 1539 is a transverse 

 section of the head of an Erne (Haliceetus albicilla), showing the con- 

 volutions of the middle turbinated cartilages, and the disposition of 

 the pituitary membrane, which is thickest on the convex or mesial 

 side of the convolutions. The air-cells in the superior maxillary 

 bones, and their communications with those which are situated in 

 front of the eyeball, are well seen in this preparation. Bristles have 

 been inserted into the lachrymal ducts, and into the common termi- 

 nation of the Eustachian tubes, the respective conduits of the eye and 

 car for conducting their superfluous moisture to the nasal passages. 

 An anterior transverse section of the head of the same eagle is shown 

 in No. 1540, which exhibits the external nostrils, the anterior termi- 

 nations of the middle turbinated cartilages, and of the lachrymal 

 ducts, in which bristles are placed ; together with the communications 

 of the maxillary air-cells with the caucellous structure of the upper 

 mandible. (' Cat. Gallery,' vol. iii.) 



" The extraordinary powers of vision," says Mr. Yarrell, " which 

 birds are known to exercise beyond any other class of animals are in 

 no genus more conspicuous that in that of Falco. Their destination, 

 elevating themselves as they occasionally do into the highest regions, 



