240 THE YELLOW WAGTAIL. 



scarcely be destroyed by birds of prey ; yet, from 

 some counteracting cause, our little certhia, instead 

 of increasing, apparently becomes a scarcer bird. 

 The limits that are appointed to the increase of all 

 the inferior orders of creation are very worthy of 

 remark. There may be periods when a great aug- 

 mentation of individual species takes place; but 

 this circumstance is local, or temporary, and future 

 numbers do not result from it. Some motive for 

 the increase, no doubt, existed ; but, the object 

 being accomplished, it ceases; and apparent events, 

 or imperceptible causes, reduce the profusion of the 

 race, so that certain numbers only continue. This 

 little tree-creeper, though always active, seems to 

 possess most animation and restlessness in the 

 autumnal months. 



The yellow wagtail (motacilla flava) is so regu- 

 larly seen with us in his season, as to be quite a 

 common bird, breeding in our fields ; yet, generally 

 observed as he is, he always invites our attention, 

 by his graceful form and brilliant plumage, either 

 actively running in our path, or sporting in the 

 pastures with that animation and ease so remarkable 

 in all this family, that we may justly distinguish 

 them as the gentles of our fields. With manners 

 and habits similar to the common grey ones, yet 

 there seems to be but little intimate association 

 between the species ; and though they are occasion- 

 ally intermixed, we most commonly observe them 

 feeding by themselves, and frolicking with their own 

 particular race. In autumn, when their broods are 



