132 The Field Naturalist 's Quarterly May- 



own object, for the ringed plover is a bird of the bare 

 sea-shore. Neither reduction in the size of its eggs — 

 sufficient to decrease probability of their discovery — nor 

 the covering of them with down or grass or leaves would 

 be possible under the present circumstances of this bird's 

 life-history. It is impossible to suggest any more suitable 

 means of hiding its treasures than protective colouration 

 of the eggs themselves; and this plan the ringed plover, 

 unconsciously perhaps, but assuredly most successfully, 

 adopts. The rudest and most simple form of bird's nest 

 is then that made by the lowest forms of bird life, whilst 

 the most elaborate structures are reared by the most 

 highly organised species. Thus ostriches merely scratch 

 holes in the sand; then we come to birds which merely 

 fill or line those holes with surrounding vegetation ; the 

 next step is to raise the eggs above the surface of the 

 land or water upon which the nest rests. 



Whether all birds were originally arboreal, and their 

 young nidifugous (W. Pycraft, ' Pop. Science,' December 

 1902), or, according to the old idea, terrestrial and nidi- 

 colous, although we can point to no present-day connecting- 

 link between praecocial and altricial habits in British breed- 

 ing-birds, we nevertheless have many instances in which 

 former, or even present - day, ground - builders sometimes 

 place their nests at some altitude from the surface of the 

 earth ; and we find much aberrancy in the architecture of 

 birds of one and the same species, even individuals of the 

 same family sometimes choosing very different sites, and 

 composing their nests very differently. The present-day 

 methods of green sandpiper, heron, crow, cormorant, stock- 

 dove, the swallow family, and house-sparrow, for instance, 

 show a remarkable amount of adaptation to varying circum- 

 stances ; whilst the plover, grebe, rook, thrush, hawfinch, 

 chaffinch, and long-tailed tit, being constant in their breed- 

 ing habits, may have arrived at what is the most perfect for 

 the comfort and safety of their offspring, and these birds 

 may be taken as representing either rising or descending 

 steps in the scale of avian architecture, according as we 

 presume the earliest forms of bird-life to have been altricial 

 or praecocial. 



