Introduction to Hering's Lecture 6i 



which results in the crash of action, unless it is timely 

 counteracted. 



If another objector maintains that the vibrations within 

 the germ as above supposed must be continually crossing 

 and interfering with one another in such a manner as to 

 destroy the continuity of any one series, it may be replied 

 that the vibrations of the light proceeding from the objects 

 that surround us traverse one another by the miUions of 

 millions every second yet in no way interfere with one 

 another. Nevertheless, it must be admitted that the 

 difficulties of the theory towards which I suppose Professor 

 Hering to incline are like those of all other theories on the 

 same subject — almost inconceivably great. 



In " Life and Habit " I did not touch upon these 

 vibrations, knowing nothing about them. Here, then, 

 is one important point of difference, not between the con- 

 clusions arrived at, but between the aim and scope of the 

 work that Professor Hering and I severally attempted. 

 Another difference consists in the points at which we have 

 left off. Professor Hering, having established his main 

 thesis, is content. I, on the other hand, went on to maintain 

 that if vjgourwas^due^to memory, want of vigour was due 

 to want of^memory. Thus I was led to connect memory 

 with the phenomena of hybridism and of old age ; to show 

 that the sterility of certain animals under domestication 

 is only a phase of, and of a piece with, the very common 

 sterility of hybrids — phenomena which at first sight have 

 no connection either with each other or with memory, 

 but the connection between which will never be lost sight 

 of by those who have once laid hold of it. I also pointed 

 out how exactly the phenomena of development agreed 

 with those of the abeyance and recurrence of memory, and 

 the rationale of the fact that puberty in so many animals 

 and plants comes about the end of development. The 

 principle underlying longevity follows as a matter of 

 course. I have no idea how far Professor Hering would 

 agree with me in the position I have taken in respect of 



