THE BLUEBIRD. 33 



evolved rapidly by these groups and individual variation is great, although 



different in character from what it is in youth. 



In the decrepitude of age, the groups, large and small, cease to be 



numerous as individuals, there is little individual variation and no species 



are evolved. 



I believe that the bluebirds of North America have long passed the 



middle period of their existence, as a group, and that they are now in the 



decrepitude of age, for all of the conditions which indicate this, as seen 

 by the foregoing, appear to be fulfilled. 



Of course when we speak of the passing away of a group or species, 

 we must consider this a very slow process, time must not be counted by 

 years nor by centuries, but by decades and epochs. Thus, while we may 



look upon our bluebird as a representative of an ancient race, which has 

 passed its vigorous stage of existence, in the common course of events, it 

 will probably long be spared to gladden our fields and orchards with its 

 cheery call. 



I have given the above digression for the benefit of teachers and their 

 pupils, for I feel that too little is known of such matters. We are apt 

 to take too superficial views in teaching nature study in schools. We had 

 better, perhaps, teach the facts in regard to the life history of one typical an- 

 imal, than to attempt to teach about any animals in a superficial manner, 

 for after all, it is the reasoning power of the pupil which we wish to 

 awaken and develop, and this can be done in no better way than in nature 

 study. 



The bluebird is among the earliest to appear among our spring birds 

 often being seen in Eastern Massachusetts during the last week in Febru- 

 ary, when the snow is still lingering in patches along the north sides of fences 

 and walls, and in the wooded valleys. 



I know of no more enlivening sound than the cheering whistle of 

 the bluebird, for when this sound reaches the ear we may be sure that 

 winter is in retreat towards the frozen north, and that genial spring has 

 come. To be sure, this most fickle goddess may occasionally give way be- 

 fore the backward glance of winter, even allowing him to cover the 

 earth with with his snowy mantle, but the bluebirds know that the sun 

 rides high in the heavens, and that the snow will soon disappear before 

 his rays. Spring soon asserts her sway, and early in the season the blue- 

 birds begin to examine the natural cavities in apple trees, and those boxes 

 put up for their use which are not occupied by the English sparrows. 



There is most anxious research on the part of the female as to the 

 condition of the cavity in which the nest is to be placed ( it must be dry 

 and sufficiently commodious to suit ) and much wing fluttering and twittering 

 on the part of the male, who accompanies her. 



