INTRODUCTION. xix 
more reason is developed the less are the other powers employed ; conse- 
quently, so far as man is concerned, they have lost much of their force 
through disuse. To credit birds with such a marvellous power as blind and 
infallible instinct in building their nests would be to place them far beyond 
man himself in intelligence, and allot to them a faculty which is super- 
human. The evidence that we are able to collect all tends to disprove 
such a mysterious power. Birds brought up in confinement do not make 
a nest typical of their species, and in most cases content themselves with 
forming the merest rudiments of a nest, merely heaping a lot of material 
together on which they lay their eggs ; and in some cases they do not make 
even this slight provision. This may be Instinct (or, more properly 
speaking, Hereditary Habit)—the blind impulse to make a nest ; but with- 
out tuition, or some standard to work by, it is a failure. The same remarks 
apply to man ; for with all his boasted reason he is equally as incapable 
of building a habitation peculiar to his race, if he has not seen one or 
been initiated in the secrets of its construction. Savage man neither alters 
nor improves any more than the birds; and each of his great races has a 
peculiar style of architecture. The Arab and the American Indian dwell 
in tents, the negro builds a hut, and the bushman lives in caves, whilst the 
Malay erects his house on posts. Transfer an infant of any one of these 
races of men, say to civilized Europe, and is it conceivable that when grown 
up to manhood he would set to work to build a tent, a hut, or a house on 
posts, according to the particular race to which he belongs, instinctively, 
and with no instruction? If man is so helpless in such a case, why should 
not the bird be the same ? Why should a creature infinitely below man in 
so many of its intellectual attributes be so far in advance of him in this 
particular respect? ‘The same remarks equally apply to a bird’s song and 
to the language of mankind—each have to be learnt. A bird’s intellectual 
powers advance towards maturity much more quickly than in the human 
species. A young bird three or four days old is capable of considerable 
powers of memory and observation, and during the time that elapses in 
which it is in the nest it has ample opportunity of gaining an insight into 
the architecture peculiar to its species. It sees the position of the uest, 
it notes the materials, and when it requires one for itself, is it so very 
extraordinary that, profiting by such experience, it builds one on the same 
plan? Again, birds often return to the place of their birth the following 
season, and possibly see the old home many times ere they want one for 
themselves. This, aided by the strong hereditary impulse to build a nest 
similar to the one in which they were born, inherited from their parents, 
aids them in their task. Further, we know that some birds do not breed 
for several seasons after they are hatched, and consequently see the older 
birds at work and profit by the experience. The nests they build may, 
and do often, vary from the original type in many slight particulars ; and 
