ON THE DIRECTIVITY OF LIFE. 



267 



capable of reproducing, each other," the change of environment 

 produces not a new species but a new variety only. Some years 

 ago, at University College, I was listening to the author as he 

 pointed out that a change of environment may modify size and 

 form, but does not affect specific differences ; and he gave as an 

 instance the American cacti, which, when grown in Africa, remain 

 of the same species, although modified in size and appearance. On 

 p. 253 we learn that Mr. G. Bentham finds "no well-marked 

 differences between any of the ninety genera of asteroidese." It 

 vv^ould be interesting to know on what system of classification that 

 gentleman proceeds in calling such groups genera," when they are 

 obviously not so. The author quotes Darwin's opinion (p. 253) 

 that changed conditions of life may produce a " new sub-variety." 

 A "new sub-variety" however, is a different thing from a new sjoecies ; 

 and the cause of true science would not be advanced by calling it 

 by the same name. 



On p. 249 (paragraphs 1 and 2) we read that "plants of no 

 relationship whatever," living in the same or similar environment 

 tend, through the influence of the environment, to become alike. 

 Is not this inconsistent with the statement that the environment 

 has caused those great and striking differences which mark off species 

 from one another 1 The several geological strata which, in 

 Sedgwick's time (p. 253), revealed distinct series of fossils and 

 distinct species which had lived side by side, makes the same 

 revelation to-day, and tells us that Sedgwick was right in believing 

 in a succession of separate creative acts. 



We shall all, I am sure, join in thanking the able author for a 

 most interesting paper. 



Mr. W. Woods Smyth : While congratulating the Victoria 

 Institute upon receiving a paper accepting evolution in any form, 

 I beg to offer the following criticisms : — 



(1) Professor Henslow appears to have changed his position. 



He used to make much of " Divine Directivity," now it is 

 the "Directivity of Life." Any theory of directivity 

 which goes beyond the dowry of attributes bestowed 

 upon life at the beginning is entirely unscientific. 



(2) The idea that species have originated through one or 

 two factors alone is opposed to all the evidence we 

 possess. 



