MEMOIR. Ixix 
voyage, independently arrived at the theory through the botany of the 
Antarctic Islands; but I was not prepared with anything like the complete 
worked out theory as Forbes enunciated it. On the other hand, I do not 
know that any one has worked out the question of the subject of the origina- 
tion of varieties, and of species of plants by geological, etc., distribution, till 
I did it in the Arctic essay. This was, of course, only an expansion, or 
rather duplication of Darwin’s principles, and indeed I do not see how I can 
claim much originality in the matter. I am more of a handmaid than a 
mistress of science. If you will ask Darwin he will, I know, give you my 
position in relation to this subject with all the credit I am entitled to a# 
least, and probably a good deal more! But I go a good deal further than 
he does in continental extension, etc., and’he than I do in belief in power of 
present agents in distributing seeds, etc., across oceans, etc. 
‘* But I must break off. Will you be my guest at the anniversary dinner 
of the Linnean Society, on Monday, 25th, at Willis’s Rooms? Pray do, 
and we can have a talk. Bentham is going to give us an anniversary 
address on ‘ Darwinism,’ dwelling I expect mostly on the methods of his 
adversaries, and their want of logic. Would you like to attend at 3 P.M. ? 
. ‘* Ever sincerely yours, 
‘Jos. D. HooKER.”’ 
fT. W. Bates to Dr. J. D. Hooker. 
‘* 22, HARWOOD STREET, HAVERSTOCK HILL, N.W., 
** May a2ist. 
‘““My DEAR DR. HOOKER, 
‘*T should very much like to hear the anniversary address of Mr. 
Bentham, but I don’t care much about the dinner afterwards ; besides, it is 
especially mentioned in the advertisement as for ‘members.’ 
‘* The looseness of my remarks has led you to suppose that, with regard 
to what Wallace said of plants alone being able to furnish data for sucha 
paper as your Arctic one, I contended against plants; but I meant to say 
that we did not know at present whether insects would not furnish equally 
good data, no attempt having yet been made. And in fact no attempt can 
be made, as insects have not yet been collected with such care in noting 
localities and ranges, as plants. Wallace seems to think that, upon the 
whole, insects are not good subjects for such investigations, but I believe 
they will turn out the very best subjects. 
“As to your paper, I think your case is proved to demonstration byplants, and 
I understand the clenching force of your illustration of Greenland quite well. 
‘*As to the most divergent varieties of variable species being found on 
the confines of its area (vertical and horizontal), I should think in the majority 
of cases it is so; but there are some striking exceptions; for instance, a 
large number of European insects furnish very divergent varieties in Corsica 
and Sardinia, whilst their normal forms range around the Mediterranean. 
Al Zriort we might say that local varieties are formed according to changes 
in the conditions of life (organic and inorganic) of their respective species ; 
and as their conditions do not always graduate off from the centre to the 
circumference of the areas, especially when isolated spots (is!ands or areas 
of land) occur within the area, therefore varieties would not graduate off. 
