412 THE CAUSES OF THE XI 
who may be pigeon fanciers, and I wish you to 
understand that in approaching the subject, I would 
speak with all humility and hesitation, as I regret 
to say that I am not a pigeon fancier. I know it 
is agreat art and mystery, and a thing upon which 
aman must not speak lightly; but I shall en- 
deavour, as far as my understanding goes, to give 
you a summary of the published and unpublished 
information which I have gained from Mr. Darwin, 
Among the enormous variety,—I believe there 
are somewhere about a hundred and fifty kinds of 
pigeons,—there are four kinds which may be se- 
lected as representing the extremest divergences 
of one kind from another. Their names are the 
Carrier, the Pouter, the Fantail, and the Tumbler. 
In these large diagrams that I have here they are 
each represented in their relative sizes to each 
other. This first one is the Carrier; you will 
notice this large excrescence on its beak ; it has a 
comparatively small head; there is a bare space 
round the eyes; it has a long neck, a very long 
beak, very strong legs, large feet, long wings, and 
soon. The second one is the Pouter, a very large 
bird, with very long legs and beak. It is called. 
the Pouter because it is in the habit of causing its 
gullet to swell up by inflating it with air. I should 
tell you that all pigeons have a tendency to do this 
at times, but in the Pouter it is carried to an 
enormous extent. The birds appear to be quite 
proud of their power of swelling and puffing them 
