[B57]

Mr Andrew Murray in an excellent paper (Transact Royal Soc. Edinburgh. Vol XXII 1861. p.  567) clearly shows that the pediculi on various races of man differ not only in colour, but in the structure of the claws & limbs. He finds moreover in several cases in which he obtained numerous specimens, that these differences were constant. He describes 2 forms from N. America & 2 from S. America, (& 2 from Australia) 4 from Africa, on Humboldt lake & W. & E Negros — but as here we have 4 in same race of man, have become differentiated at quicker rate. Yet no doubt a distant species of Pediculus wd be used in other cases as argument of specific distinction

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[B57v]

The crucial point is that, as far as observed, the same identical species, exists on the different varieties of the dog, fowl & pigeon. But probably foreign races of these animals have not been observed.

Murray, Andrew. 1861. On the pediculi infesting the different races of man. Transactions of the Royal Society of Edinburgh 22: 567-578. Darwin cited this in Descent 1: 219-20. n8: "'Transact. R. Soc. of Edinburgh,' vol. xxii. 1861, p. 567." Pediculus is a genus of sucking lice.