Names of Breeds.

Actual Weight of Femur and Tibia.

Actual Weight of Humerus and Ulna.

Weight of Wingbones relatively to the Leg-bones, in comparison with these same bones in G. bankiva.

Grains.

Grains.

Gallus bankiva

wild male

86

54

100

1

Cochin

male

311

162

83

2

Dorking

male

557

248

70

3

Spanish (Minorca)

male

386

183

75

4

Gold Spangled Polish

male

306

145

75

5

Game, black-breasted

male

293

143

77

6

Malay

female

231

116

80

7

Sultan

male

189

94

79

8

Indian Frizzled

male

206

88

67

9

Burmese Jumper

female

53

36

108

10

Hamburgh (pencilled)

male

157

104

106

11

Hamburgh (pencilled)

female

114

77

108

12

Silk (black-boned)

female

88

57

103

In the eight first birds, belonging to distinct breeds, in this table, we see a decided reduction in the weight of the bones of the wing. In the Indian Frizzled fowl, which cannot fly, the reduction is carried to the greatest extent, namely, to thirty-three per cent. of their proper proportional weight. In the next four birds, including the Silk-hen, which is incapable of flight, we see that the wings, relatively to the legs, are slightly increased in weight; but it should be observed that, if in these birds the legs had become from any cause reduced in weight, this would give the false appearance of the wings having increased in relative weight. Now a reduction of this nature has certainly occurred with the Burmese Jumper, in which the legs are abnormally short, and in the two Hamburghs and Silk fowl, the legs, though not short, are formed of remarkably thin and light bones. I make these statements, not judging by mere eyesight, but after having calculated the weights of the leg-bones relatively to those of G. bankiva, according to the only two standards of comparison which I could use, namely, the relative lengths of the head and sternum; for I do not know the weight of the body in G. bankiva, which would have been a better standard. According to these standards, the leg-bones in these four fowls are in a marked manner far lighter than in any other breed. It may therefore be concluded that in all cases in which the legs have not been through some unknown cause much reduced in weight, the wing-bones have become reduced in weight relatively to the leg-bones, in comparison with those of G. bankiva. And this reduction of weight may, I apprehend, safely be attributed to disuse.

To make the foregoing table quite satisfactory, it ought to have been shown that in the eight first birds the leg-bones have not actually increased in weight out of due proportion with the rest of the body; this I cannot show, from not knowing, as already remarked, the weight of the wild Bankiva.[[434]] I am indeed inclined to suspect that the leg-bones in the Dorking, No. 2 in the table, are proportionally too heavy; but this bird was a very large one, weighing 7 lb. 2 oz., though very thin. Its leg-bones were more than ten times as heavy as those of the Burmese Jumper! I tried to ascertain the length both of the leg-bones and wing-bones relatively to other parts of the body and skeleton; but the whole organisation in these birds, which have been so long domesticated, has become so variable, that no certain conclusions could be reached. For instance, the legs of the above Dorking cock were nearly three-quarters of an inch too short relatively to the length of the sternum, and more than three-quarters of an inch too long relatively to the length of the skull, in comparison with these same parts in G. bankiva.

In the following Table II. in the two first columns we see in inches and decimals the length of the sternum, and the extreme depth of its crest to which the pectoral muscles are attached. In the third column we have the calculated depth of the crest, relatively to the length of the sternum, in comparison with these same parts in G. bankiva.[[435]]

Table II.

Names of Breeds.

Length of Sternum.

Depth of Crest of Sternum.

Depth of Crest, relatively to the length of the Sternum in comparison with G. bankiva.

Inches.

Inches.

Gallus bankiva

male

4.20

1.40

100

1

Cochin

male

5.83

1.55

78

2

Dorking

male

6.95

1.97

84

3

Spanish

male

6.10

1.83

90

4

Polish

male

5.07

1.50

87

5

Game

male

5.55

1.55

81

6

Malay

female

5.10

1.50

87

7

Sultan

male

4.47

1.36

90

8

Frizzled hen

male

4.25

1.20

84

9

Burmese Jumper

female

3.06

0.85

81

10

Hamburgh

male

5.08

1.40

81

11

Hamburgh

female

4.55

1.26

81

12

Silk fowl

female

4.49

1.01

66

By looking to the third column we see that in every case the depth of the crest relatively to the length of the sternum, in comparison with G. bankiva, is diminished, generally between 10 and 20 per cent. But the degree of reduction varies much, partly in consequence of the frequently deformed state of the sternum. In the Silk-fowl, which cannot fly, the crest is 34 per cent. less deep than what it ought to have been. This reduction of the crest in all the breeds probably accounts for the great variability, before referred to, in the curvature of the furcula, and in the shape of its sternal extremity. Medical men believe that the abnormal form of the spine so commonly observed in women of the higher ranks results from the attached muscles not being fully exercised. So it is with our domestic fowls, for they use their pectoral muscles but little, and, out of twenty-five sternums examined by me, three alone were perfectly symmetrical, ten were moderately crooked, and twelve were deformed to an extreme degree.

Finally, we may conclude with respect to the various breeds of the fowl, that the main bones of the wing have probably been shortened in a very slight degree; that they have

certainly become lighter relatively to the leg-bones in all the breeds in which these latter bones are not unnaturally short or delicate; and that the crest of the sternum, to which the pectoral muscles are attached, has invariably become less prominent, the whole sternum being also extremely liable to deformity. These results we may attribute to the lessened use of the wings.

Correlation of Growth.—I will here sum up the few facts which I have collected on this obscure, but important, subject. In Cochins and Game-fowls there is some relation between the colour of the plumage and the darkness of the egg-shell and even of the yolk. In Sultans the additional sickle-feathers in the tail are apparently related to the general redundancy of the plumage, as shown by the feathered legs, large crest, and beard. In two tailless fowls which I examined the oil-gland was aborted. A large crest of feathers, as Mr. Tegetmeier has remarked, seems always accompanied by a great diminution or almost entire absence of the comb. A large beard is similarly accompanied by diminished or absent wattles. These latter cases apparently come under the law of compensation or balancement of growth. A large beard beneath the lower jaw and a large top-knot on the skull often go together. The comb when of any peculiar shape, as with Horned, Spanish, and Hamburgh fowls, affects in a corresponding manner the underlying skull; and we have seen how wonderfully this is the case with Crested fowls when the crest is largely developed. With the protuberance of the frontal bones the shape of the internal surface of the skull and of the brain is greatly modified. The presence of a crest influences in some unknown way the development of the ascending branches of the premaxillary bone, and of the inner processes of the nasal bones; and likewise the shape of the external orifice of the nostrils. There is a plain and curious correlation between a crest of feathers and the imperfectly ossified condition of the skull. Not only does this hold good with nearly all crested fowls, but likewise with tufted ducks, and as Dr. Günther informs me with tufted geese in Germany.

Lastly, the feathers composing the crest in male Polish fowls resemble hackles, and differ greatly in shape from those in the crest of the female. The neck, wing-coverts, and loins