32 
president’s address. 
each would have to combat with for their existence in an 
undisturbed state of nature, we find that in all cases ample 
provision has been made for the needs of each individual 
species, so as to preserve the balance of creation. “Each 
has its allotted space to fill and duties to perform.” 
I now come to the largest group, viz., those birds that lay 
beautiful eggs cradled in perfect gems of ornithological 
architecture. I think we shall fmd that in these species 
there is a considerable amount of affection and tender care 
displayed for the progeny. You must certainly know with 
what valour and determination a robin or a flycatcher will 
defend their nest from a cat, for instance, by exerting their 
puny powers to the utmost, returning again and again to the 
attack, and will often succeed in driving off the intruder. 
Moreover, the young when hatched are naked, perfectly help¬ 
less, unable to feed themselves, and frequently blind; an 
exact opposite to those species who deposit their eggs on the 
ground, and have the young covered, and able, immediately 
upon leaving the shell, to procure their own food. I think 
the variation of ground colour and markings is considerably 
more in this group than in any other. I therefore place 
considerable importance upon the structure and material of 
the nest in determining the species, as they do not vary in 
anything like the same degree as the eggs. Take, for example, 
the willow and wood wrens; it is quite possible to find two 
clutches of eggs so much alike that they would answer to 
either species; but, supposing one clutch was found in a 
feather-lined nest and the other without, I should have no 
hesitation in assigning the eggs found in the feather-lined 
nest to the willow wren, as that species always uses feathers, 
whereas the wood wren does not. Take the nest of the black¬ 
bird and thrush ; the former constructs its nest of mud fibres 
and bents, forming strong walls, lined with finer bents or fibres. 
The latter constructs a similar one, but usually lines it with a 
smooth coating of cow-dung. The differences in the nests of 
these closely allied species are not to be accounted for by any 
acquired knowledge or experience, but clearly show that 
Providence has, for some wise purpose, ordained each of these 
species to construct its nests most conducively to the well¬ 
being of their offspring, and it is our ignorance that prevents 
us from ascertaining the particular reason for such difference. 
Those species forming compact nests with helpless young 
rarely leave the nest for any length of time, but one or other 
of the parents keeps watch in close proximity, to render 
protection in case of need. The magpie is a notable instance 
as an exception; to obtain food for the young, the parents 
