‘“* Mental Evolution in Animals” 69 
development to maturity by an unconscious memory, Dr. 
Creighton says that ‘‘ Professor Bain calls reproduction the 
acme of organic complication. ” “ T should prefer to say,” 
he adds, “ the acme of organic implication ; for the reason 
that the sperm and germ elements are perfectly simple, 
having nothing in their form or structure to show for the 
marvellous potentialities within them. 
“IT now come to the application of these considerations 
to the doctrine of unconscious memory. If generation is 
the acme of organic implicitness, what is its correlative in 
nature, what is the acme of organic explicitness ? Obvi- 
ously the fine flower of consciousness. Generation is 
implicit memory, consciousness is explicit memory ; 
generation is potential memory, consciousness is actual 
memory.” 
Tam not sure that I understand the preceding paragraph 
as clearly as I should wish, but having quoted enough to 
perhaps induce the reader to turn to Dr. Creighton’s book, 
I will proceed to the subject indicated in my title. 
