THE BEGINNINGS OF LIFE. 591 



nature of the conditions themselves 1. He comes to 

 this conclusion because, as he says, ^ instances could be 

 given of similar varieties being produced from the same 

 species under external conditions as different as can 

 well be conceived ; and, on the other hand, of dissimilar 

 varieties being produced under apparently the same 

 external conditions/ 



Numerous facts and reasons might be cited in favour 

 of the correctness of this view. It has long been fami- 

 liar, for instance, to all who have studied the lowest 

 forms of life, that the organisms which appear in in- 

 fusions of different organic substances are often quite 

 different in character; whilst each particular kind of 

 decaying substance is characterized by its own peculiar 

 form of Mould. Then, again, we know that alterations 



^ See ' Origin of Species,' 5th ed., pp. 8 and 166. Prof. Owen, more- 

 over, is of the same opinion. The influence of internal tendencies, he 

 says, is displayed by the fact that in a comparatively defined theatre ' the 

 various polypes of the coral reef display their diversities of colour, size, 

 shape, and structure, independently of outward influences.' He says 

 that, 'of the 120 kinds of coral enumerated by Ehrenberg in the Red 

 Sea, 100 at least exist under the same conditions.' (' Anatomy of the 

 Vertebrates,' vol. iii. p. 808.) On the other hand, the polypes of a coral 

 reef must remain essentially the same kinds of organisms (however 

 subject to minor changes) during the many thousands of years in which 

 the reef has been forming, and this fact is more in accordance with 

 Mr. Spencer's notions than with my own, unless — as I am inclined to 

 think — the inherent causes of change whose influence is at first manifest 

 in producing differentiation, become more and more diminished in in- 

 tensity after even a rudimentary organization has been attained. So 

 that after a time that change of conditions, which Mr. Spencer be- 

 lieves to be so all-essential, may become necessary in order to induce 

 further variation. (See p. 608.) 



