WCP3886

[1]

Parkstone, Dorset.

Dec.[embe]^r 31st. 1898

H. N. Ridley Esq.¹

Dear Mr. Ridley

Many thanks for your note about the Nutmeg disease & its supposed cause. I was in Singapore for some months in 1862, and had many conversations about it with D^r. Oxley (I think that was his name) who had a ruined nutmeg plantation himself, & had been to Banda to report on the Dutch plantations, and I found that he to a great extent agreed with me that it was the unnatural exposure of the young trees that produced the unhealthiness that allowed the beetle to attack & kill the trees. Every effort [2] was made to destroy the beetle, its eggs, & larvae, but it was useless. I remember also that he showed me a fine, large, & perfectly healthy nutmeg tree in the grounds of Government House, growing surrounded by other trees & therefore with the partial shelter the young trees want, & it produced a fair amount of fruit. I see, too, in the Trans.[actions] of the Ent.[omological] Soc.[iety], just received, there is a reference to several species of Scolytidae received from Penang, as being — "injurious to Nutmeg trees." Also several from Ceylon injurious to the Cacao trees, and Mr. Green, who sent them, remarks that they are not the primary cause of the disease, which is a fungus, the [3] beetles only attacking the diseased trees. As the tree does mature grow in the shade of tall trees and does produce fruit abundant<ly> when grown under those condition<s> in Banda ^{(almost identical in climate with Singapore)} — & that a tree grown under similar conditions in Singapore was healthy while all others in the island were attacked, and as the disease still exists, apparently, in Penang I am still disposed to think that the forcing of the trees by too much exposure to the sun in their earlier stages was the chief, if not the only, cause of the disease in Singapore, the beetle being [4] a secondary result. Exactly the same thing occurred with the coffee in Ceylon, with the added stimulus (I believe) of manure. But I should not have mentioned the case had I th not thought that the unnatural conditions of growth were ^{admitted to be,} at all events, one of the main causes of the disease. It seems to me very doubtful if insects are the primary case of any disease in plants.

Excuse this long rigmarole. I lost my notebooks on Singapore & Molucca[?], or I should have given fuller details of many things in my Malay Archipelago. Envying you the glorious warmth and sunshine of the Equator (which I never speak disrespectfully of)

Believe me | Yours very faithfully | Alfred R. Wallace [signature]