332 Mr. P. R. Lowe on Coloration as a Factor in 



pairs of birclsj widely separated as they are in the matter of 

 both latitude and longitude. Even allowing that, in the 

 case of the Stone-Curlews, the immediate environmental 

 details of the Norfolk ''Brecks'' were precisely identical 

 with those of the "Never Never Lands/' or the arid plains 

 of Australia, it is quite beyond our ordinary powers of con- 

 ception to imagine how such a contingency could possibly 

 have brought about such a marvellous and faithful replica 

 of colour-pattern in two nestling species, separated as they 

 are by the whole vast space occupied by the continent of 

 Asia, and even although we allow an euorm'ous amount 

 of time for the action of Natural Selection in rejecting 

 untold numbers of cases of the " unfit " which would not 

 satisfy the equation. 



In a word, it seems quite unthinkable that either 

 environment or Natural Selection, or both combined, could 

 directly affect the action of the germ-cells. We there- 

 fore come back to the statement previously made at the 

 outset of these remarks, viz., that the germ-cells are the 

 original designers of colour-pattern, that such colour-patterns 

 are submitted to the approval of a committee formed by 

 environment and Natural Selection, and if passed they 

 persist. The " little by little " theory or the transmission of 

 gradual accumulations of minute and favourable variations, 

 acquired as the result of the influence of external factors 

 during the life of any particular organism, and which 

 favourable variations permit an ascendency over the parent 

 stock, still remains a theory. In practice, we have abso- 

 lutely no evidence to substantiate it. Even allowing, as 

 seems evident and certain, that certain changes can be 

 produced by environmental effects, " how can we suppose 

 it in the smallest degree likely that very precise new 

 and adaptative powers can be conferred on the germ-cells 

 by such treatment (Bateson, "Problems of Genetics'^). 

 The colour-pattern, then, in these two pairs of nestling Plovers 

 is a deep-seated and important phenomenon. It owes its 

 origin to the independent jtigglery which went on in the 

 germ-cells of the ancestral progenitors of the Stone-Curlews 



