180 DOMESTIC PIGEONS : Chap, V. 



whereas pigeons of other colours are born well-clothed with 

 down. Mr. Esquilant, however, has observed that young 

 dun Carriers are not so bare as young dun Barbs and Tumblers. 

 Mr. Tegetmeier has seen two young birds in the same nest, 

 produced from differently coloured parents, which differed 

 greatly in the degree to which, they were at first clothed with 

 down. 



I have observed another case of correlation which at first 

 sight appears quite inexplicable, but on which, as we shall 

 see in a future chapter, some light can be thrown by the law 

 of homologous parts varying in the same manner. The case 

 is. that, when the feet are much feathered, the roots of the 

 feathers are connected by a web of skin, and apparently in cor- 

 relation with this the two outer toes become connected for a 

 considerable space by skin. I have observed this in very 

 many specimens of Pouters, Trumpeters, Swallows, Roller- 

 tumblers (likewise observed in this breed by Mr. Brent), and 

 in a lesser degree in other feather-footed pigeons. 



The feet of the smaller and larger breeds are of course 

 much smaller or larger than those of the rock-pigeon ; but 

 the scutellas or scales covering the toes and tarsi have not 

 only decreased or increased in size, but likewise in number. 

 To give a single instance, I have counted eight scutella? on the 

 hind toe of a Runt, and only five on that of a Short-faced 

 Tumbler. AVith birds in a state of nature the number of the 

 scutellse on the feet is usually a constant character. The 

 length of the feet and the length of the beak apparently 

 stand in correlation ; but as disuse apparently has affected 

 the size of the feet, this case may come under the following 

 discussion. 



On the Effects of Disuse. — In the following discussion on the 

 relative proportions of the feet, sternum, furculum, scapulae, 

 and wings. I may premise, in order to give some confidence to 

 the reader, that all my measurements were made in the same 

 manner, and that they were made without the least intention 

 of applying them to the following purpose. 



I measured most of the birds which came into my possession, from 

 the feathered base of the beak (the length of beak itself being so 

 variable) to the end of the tail, and to the oil-gland, but un- 

 fortunately (except in a few cases) not to the root of the tail ; I 



