1900.] Anderson. — Sterna of Domestic Foivh. 151 



tion, and Ray Laukester has pointed out how a tissue of high 

 potential value may, in vanishing, afiford food for the manu- 

 facture of more massive tissues less highly organized. Hence 

 one must exercise much caution in coming to a conclusion 

 with reference to the real origin of the deformities in fowls. 

 The following breeds of fowl were kept separate for some 

 years : — Minorcas, Leghorns, Plymouth Rocks, Brahmas, and 

 Spanish Blacks. Two lyCghorns showed wry tails ; all the 

 others were free from any marked deformity of this kind. 

 Crooked-keeled sterna were, however, frequent. The most 

 crooked keel of those preserved by me belonged to a Brahma. 

 The keel where the bend is greatest is almost horizontal. 

 There are marks of pressure in some cases. A broadening of 

 the edge is perceptible in two keels bent to the right and in 

 four bent to the left. An indentation occurs in front of the 

 middle of two sternal keels bent to the left. Two keels have 

 marks of beitig broken and reunited. The bend of the keel 

 is to the left in nine cases out of fifteen, and in six keels 

 to the right. The keels are sometimes crooked in water-fowl 

 which do not roost. There is a note to the effect that a 

 ''Black Norfolk Turkey" with a crooked breast was mated 

 with a straight-breasted hen. The roosts were low and flat, the 

 reporter goes on to say, five male birds out of sixteen had 

 crooked breasts. The separate flocks referred to above were 

 allowed to intermingle after some years, with the result that 

 the crooked keels diminished in number. Guinea-fowls seem 

 not to follow the lines of the ordinary domestic fowl. Those 

 under observation at present have straight keels although 

 they are the fifth generation from a common stock. It is 

 possible that the original eggs were not laid by the same 



bird. 



The table herewith appended contains the answers of some 

 of the best known English fancy-fowl breeders to a series of 

 questions I sent round. The answers and foregoing records 

 seem to show that (i) in-and-in breeding, (2) the nature of 

 the roosts, (3) the nature of the season, (4) early hatching, 

 (5) defective food and cold may all contribute to produce 

 variations, and may rank among the predisposing, con- 

 genital, exciting, and concomitant causes of the anomalies. 



