WCP768

[1]

The Dell, Grays, Essex.

Aug.[ust] 10th. 1872

Dear Lord Walden

Many thanks for the copy of your admirable catalogue of Celebes birds just received. Your excellent tables of distribution of genera show clearly most of the peculiarities of the island,— but they leave it almost doubtful to any ordinary reader whether the affinity is more with the Indian or the Australian Region. I believe your own notion is that the former has the preponderance ^{or at all events that it is a very doubtful point}. Allow me therefore to point out one mode of comparison you have not given, but which I think proves the Australian to be the [2] Region to which Celebes belongs.

You very properly reject from Table.V. all Indian genera which are non-Malayan, and you will find that almost every one of the genera given inhabit Borneo and Java, the two islands nearest to Celebes. But in Table VI. you do not reject a number of purely Papuan genera which are wholly absent from the Moluccas and Timor, & cannot therefore be expected to occur in Celebes. If you reject all but Moluccan & Timorese genera you will have a very much smaller number not occurring in Celebes, & thus proportionately increase its Moluccan (Australian Region) affinities. I think a fair test would be to state the proportion between them thus:

[3] Total Moluccan Genera

Moluccan Genera in Celebes

and

Total Borneo & Java Genera

Borneo & Java Genera in Celebes.

Also

Total Moluccan genera

Moluccan Genera absent from Celebes

and

Total Borneo & Java Genera

Borneo & Java genera absent from Celebes

The two sets compared would I think show a decided preponderance of affinity with the Australian Region.

I wish also to explain a slight misprint or oversight in my List of Sula Birds. You say I give the locality of Sula to Graucalus temminckii on Müllers authority. But I intended the (Müller) to apply only to the Celebes habitual[?] — I having a ♀ specimen of the Bird from Sula. The list is a [4] list of a collection made in Sula by my Assistant, and I was not and am not aware of any birds from Sula having been previously described.

Believe me | Yours very faithfully | Alfred Russel Wallace [signature]

The Viscount Walden