Introduction xix 



into a continuous organ, or more or less surrounded by 

 tissue-cells, whose part it is to nourish them, are called 

 " secondary embryonic cells," or " germ-cells." The germ- 

 cells may be differentiated in the young organism at a 

 very early stage, but in Plants they are separated at a 

 much later date from the less isolated embryonic regions 

 that provide for the Plant's branching ; in all cases we 

 find embryonic and germ-cells screened from the life pro- 

 cesses of the complex organism, or taking no very obvious 

 part in it, save to form new tissues or new organs, notably 

 in Plants. 



Again, in ourselves, and to a greater or less extent in all 

 Animals, we find a system of special tissues set apart for 

 the reception and storage of impressions from the outer 

 world, and for guiding the other organs in their appropriate 

 responses — the " Nervous System " ; and when this system 

 is ill-developed or out of gear the remaining organs work 

 badly from lack of proper skilled guidance and co-ordina- 

 tion. How can we, then, speak of " memory " in a germ- 

 cell which has been screened from the experiences of the 

 organism, which is too simple in structure to realise them 

 if it were exposed to them ? My own answer is that we 

 cannot form any theory on the subject, the only question 

 is whether we have any right to infer this " memory " 

 from the behaviour of living beings ; and Butler, like 

 Hering, Haeckel, and some more modern authors, has shown 

 that the inference is a very strong presumption. Again, 

 it is easy to over-value such complex instruments as we 

 possess. The possessor of an up-to-date camera, well 

 instructed in the function and manipulation of every part, 

 but ignorant of all optics save a hand-to-mouth knowledge 

 of the properties of his own lens, might say that a priori 

 no picture could be taken with a cigar-box perforated by 

 a pin-hole ; and our ignorance of the mechanism of the 

 psychology of any organism is greater by many times than 

 that of my supposed photographer. We know that Plants 

 are able to do many things that can only be accounted for 



