﻿112 FIELD AND FOREST. 



them of advantages offered by the association with many individuals 

 of their kind ; prevents them from learning how to provide the custom- 

 ary place for incubation ; and accounts for their impotency in this res- 

 pect. He is probably not conversant with the fact that animated 

 nature of inferior order kept in confinement for any length of time 

 becomes anomalous; some part of the organism is modified, — espec- 

 ially the essential organs, — and being in this abnormal condition, the 

 bird necessarily does not have full possession of its faculties (be they 

 what they are) and consequently cannot be expected to produce such 

 a complicated affair, as a nest generally is, in as complete and perfect 

 a manner as when in a normal and free state. And it is too notorious 

 to require comment, that animals in a high state of cultivation, not 

 only acquire new wants as well as new habits, but lose many of their 

 natural qualities and instincts. 



His principal illustrations in relation to improvement in nests, ap- 

 pear to be deduced from the observations of M. Pochet who pub- 

 lished in 1870, some notices of progressive improvement in martins' 

 nests. '- He kept for forty years in the Rouen Museum some of these 

 nests, which he bad himself detached from the walls of old buildings in 

 that city. Having one day got some new nests, be was amazed, on com- 

 paring them with the old, to perceive considerable differences." The 

 new style nests were all built on the same plan and differed from the 

 old style, "which is a quarter hemisphere, having a very small circu- 

 lar orifice," in having "a width greater than their depth, forming a 

 segment of an oblate spheroid, the orifice being very wide." Here he 

 says, "we see an evident progress, the new type being larger, more 

 comfortable." 



This is only analogous to another instance he mentions, which 

 does not strike him as being very remarkable. The instance referred 

 to is, that the common sparrow (and it is to be noticed in almost all 

 other birds) when building its nest in open and exposed situations 

 constructs it in a solid and covered manner ; but when it can avail 

 itself of a nook in a wall it is far less particular, putting it loosely to- 

 gether. The improved martins' nests were, as he says, built in peril- 

 ous places ; they therefore demanded more attention in construction 

 and finish, this resulting in the "new style." Whether this progres- 

 sive improvement shall continue under all conditions — safe as well as 

 dangerous — is more than doubtful. 



