PROGRESS, BIOLOGICAL AND OTHER 21 



by which the sexes recognize each other is so crude 

 that I am not sure whether it deserves the term 

 recognition at all. Before mating, which takes place 

 immediately after a moult, the female is carried 

 about for some time in the claws of the male. The 

 mature males will attempt to lift up and carry off 

 any members of the same specie:, male or female: 

 but the only ones which will permit themselves to be 

 thus carried about are females just before moulting. 

 Hence by a general instinct to lift any members of 

 the same species on the part of the males, and on the 

 part of the females an instinct to allow themselves to 

 be lifted when in the physiological condition which 

 precedes moulting, the required end is brought about. 

 But of any mental operation such as is involved in 

 sex-recognition in man or any other mammal, there 

 is no evidence. 



Fish, to take another example, possess associative 

 memory; they can learn. But they learn very 

 slowly, and learn only the simplest things. The 

 jump from their powers of memory to those of a dog, 

 who can be trained comparatively quickly to carry 

 out complicated tricks, is as great as the further 

 jump from the powers of a dog to those of a man 

 capable of learning a page of print by heart in two 

 or three readings. 



The first organs connected with mind to become 

 elaborated are the organs of sense : but such receptor 

 organs are useless to their possessor, however elabo- 

 rate, unless put into relation with proper effector or- 



