V. 
Lord Walsingham replied to this in the succeeding part of the “Young 
Naturalist,” and contended that Mr. Dale’s arguments supported his 
theory, and that differing from “birds and other animals, which require 
to retain heat rather than to absorb, and as quickly radiate, or loose 
it, insects, on the contrary, require rapidly to take advantage of 
transient gleams of sunshine during the short summer season, and may 
be content to sink into a dormant condition so soon as they have 
secured the reproduction of their species." 
The next to write upon the subject was Dr. Chapman, who said 
he considered Melanism to be “ a western rather than a northern form 
of variation ; to be associated with a wet rather than a cold climate ; 
and it has certainly been more common of recent years, which may be 
attributed to the long succession (unprecedented) of wet seasons we 
have passed through.” 
I now have very briefly reviewed the various articles that had 
appeared prior to 1890, when Mr. Tutt gave his theory to the world. 
From what I have already quoted it will be seen that the idea that 
moisture was the cause of Melanism did not originate with Mr. Tutt, 
and indeed, he tells us that it was first suggested to him by a paper 
read by Mr. Cockerell at the South London Entomological and 
Natural History Society in 1887. But I call it his theory because he 
was the first to connect it with the warm waters of the Gulf Stream, 
and further, because he made. himself responsible for it in a very 
unusual way. It was produced as the first Editorial communication 
to a new Magazine which claimed for itself special connection with 
questions affecting variation, and being reprinted in a volume of nearly 
70 pages, it obtained an amount of attention it would certainly not 
have received had it appeared as an ordinary magazine article. 
Mr. Tutt tells us on p. 65, that what he has “ written on this subject 
has grown from a comparatively short paper prepared a considerable 
time ago.” It is easy to see this was so, for in studying the pamphlet 
we find in the first few pages a clearly defined and perfectly intelligible 
theory, which if not absolutely original in conception, was certainly 
so in the manner in which the facts and arguments were marshalled 
and presented in support of the leading idea. But as the paper grew, 
this clearly defined theory became dim and obscure, and so many side 
issues were raised and discussed, that the original idea was almost, 
if not entirely lost sight of. 
Mr. Tutt refers to the Gulf Stream as having a very well known 
influence on our climate, and shows how. the westerly winds which 
prevail in Britain “ blow over the Gulf Stream, hence in their course 
they become exceedingly humid, and laden with moisture before they 
reach our shores.” He then points out the districts in Britain which 
he considers most affected by this assumed humidity from the Gulf 
