12 SCIENCE (PROGRESS. 
The preservation of complexion after a race has migrated 
to a very different climate conforms to the general law. 
Although the parents may alter greatly “the adventitious 
colour has no influence on the offspring ”. 
Hence in looking for the causes of varieties of mankind 
we must not ‘direct our attention to the class of external 
powers which produce changes on individuals in their own 
persons, but to those more important causes, which acting on 
the parents, so influence them that they produce an offspring 
endowed with certain peculiar characters, which characters, 
according to the law of nature, become hereditary, and thus 
modify the race”. 
The sentence I have last quoted concludes the section 
and very naturally introduces section iv., entitled, ‘‘ Theory 
of the Origin of Varieties” (p. 548). 
This section opens with a sentence which might well 
have been written by Darwin: “ Varieties of form or 
colour, as they spring up in any race, are commonly called 
accidental, a term only expressive of our ignorance as to 
the causes which give rise to them”. - On the other hand— 
“how, by what influence, and tx what manner” they are 
produced, “we shall perhaps never be able to ascertain”. 
Examples of new varieties which have sprung up within 
the experience of man are then given: the “ porcupine” 
and six-fingered man, albinos and variations in colour. He 
next describes the sudden origin of the ancon or otter 
breed of sheep, quoting from Col. Humphries in the 
Philosophical Transactions for 1813 (part 1.). 
Prichard favours the view that when the offspring does 
not exhibit a new variety but follows the main lines of its 
race or breed, it is apt to be influenced by the father rather 
than the mother ; and he quotes a number of statements and 
opinions believed to favour this view ; and finally alludes to 
the celebrated cross between the mare and the male quagga 
in which it was confidently believed that so great an effect was 
produced on the former that her later offspring, although 
begotten by a stallion, were influenced in the direction of 
the quagga (telegony). 
The mother, on the other hand, was believed to be in 
