xlvi MEMOIR. 
Dr. Hooker has also written a most friendly letter on the subject, valuing 
the treatise highly. Mr. Wallace and I discussed the matter last time 
I was in London, and he thinks me entirely right. As for the ‘mob’ 
of naturalists, I don’t care much about them. There is only one man in 
Europe who will be able to follow my reasonings, species by species and 
variety by variety; this is Dr. C. Felder, of Vienna, and I shall be glad to 
hear from him upon the subject. As to ordinary entomologists, they cannot 
be considered scientific men, but must be ranked with collectors of postage- 
stamps and crockery. 
‘‘T wish to have more criticisms from you on the subject when you are 
quite at leisure. (What anidea!) Iam sure I could now put the case much 
more strongly. But you say the argument is quite clear, so I must rest 
contented. I now believe one of the forms of Leptalis (L. Argochloe) is 
not an immediate descendant from L. Theonoé, as the other varieties are, but 
has originated (in a similar way) somewhere westward, in Andean valleys, 
and has wandered to the Amazons. It would be tedious here to give reasons. 
Does it occur to you that a great deal may be unexpectedly learnt by thus 
thoroughly going into one small group of natural objects? The more I study 
them the more I am surprised at the wonderful revelations which spring 
from them: much more than is explained in my treatise... .” 
The following is,the letter from Dr. Hooker, to which Bates 
refers :— 
Dr. F. D. Hooker to H. W. Bates. 
“‘ Kew, LVovember 13th, 1862. 
‘““ My DEAR MR. BATES, 
“‘One line to say how greatly I am delighted with your paper in the 
Linnean. I hope indeed that you will give us another. It is a most in- 
vigorating essay, and will, I am sure, please Darwin vastly. I like both 
the conception and execution of it, and hope you find that our society has 
done justice to the paper. 
‘‘T have only one criticism: at page 508, where, line 10, you say— 
cautiously enough—that ‘similar varieties in two (already)* nearly allied 
forms do sometimes show that they have been affected (in a similar way) * by 
physical conditions,’ and you go on to quote seaside habitat.- Now I do not 
see how you apply Akyszcal conditions here, logically, as a cause different in 
kind and operation from zafural conditions elsewhere. After all seaside is 
only, in other words, ‘conditions only found near sea’—not necessarily the 
seaside itself at all. If the physical conditions of sea act at all, they can 
only act as natural conditions do by favouring races, e.g., you would perhaps 
say that sea atmosphere and succulent habits of plants, going so often together, 
was sign of plants being affected by physical conditions. I say: Not at all. 
It only shows that those varzefzes alone which are so constructed as to resist 
the effects of superabundant humidity have survived. We know em{Zzrically 
* These words are omitted in Dr. Hooker’s letter. 
t Bates’s words are: “ A great number of insects are modified in one direction by a 
seaside habitat.” 
