296 
On t/ie Cultivated Potato. 
sum. Now for my special difficulty. I cannot find any sufficient 
study of the potato-plant in its natural habitat. Humboldt 
merely just mentions its growth : Darwin, in his voyage round 
the world — Chonos Islands, lat. 45° — mentions great abundance 
in sandy, shelly soil near the beach, some plants four feet high : 
the tubers have the same smell and appearance as the English 
potato. Darwin goes on to remark that " the same plant is 
found on the sterile mountains of Central Chili, where a drop 
of rain does not fall for six months, and within the damp 
forests of these southern islands." Now all this is not enough 
for my purpose : I want a careful study. Does the plant 
grow in large clumps, or in single families, interspersed with 
other vegetation ? if so, the nature of any such vegetation with 
which the potato lives in friendly cohabitation ; and a thousand 
other facts which will occur to your trained mind should be 
known. This is a principle of mine evolved for the purposes 
of the present inquiry — the more artificial the condition, the 
more necessary it is to couple nature with freedom, and to study 
this combination, with a view to all possible conformity. 
I have made an unworthy precis of the interesting letters I 
received from Mr. Baker, under dates from June 4 to December 
27, 1883. 
Mr. Baker sees no reason to doubt the conclusions stated as 
to the disease and degeneracy of the potato-plant ; * the life- 
history of its parasitic fungi has been fully investigated, they 
would not attack the plant if it were grown under normal 
conditions. The question asked, what are the normal con- 
ditions? is a fair and proper question to put to a botanist, 
but a very difficult and complicated one to answer. The uni- 
versally accepted botanical authority f on the subject gives 
some twelve or fifteen species closely allied to the cultivated 
potato : it stands to reason the climatic requirements of these 
several species, widely distributed over a vast continent, must 
be exceedingly different. Yet their botanical differences are 
small, and their relationship to one another and to the cultivated 
potato have never been adequately investigated. In regard to 
the extract cited from Darwin's voyage of the 'Beagle,' in which 
he gives an account of the potato growing wild in the Chonos 
Archipelago, off the coast of Patagonia, where the climate is very 
damp and equable, I have examined Darwin's original speci- 
men, and I am quite satisfied that the plant is not Solanum 
* Mr. Thistleton Dyer, F.R.S. [sec ante, p. 291], notes, "1 lake it tlic renson 
the potato nxmld is so powerful is, tlint we grow the potato in large areas — 
Nature docs not; we put our eggs, at any rate, large paicels of them, into one 
basket — Nature knows bett( r ! 
t Monograph by Dunal in the 13th volume of De Candolles Prodromus.' 
