54 the president's address. 



given by Fabre of the larvae of the Sitaris beetle, which he says is 

 first hatched in the nests of some bees as a minute, active creature 

 with six legs, long antennas, and four eyes. The male bees emerge 

 before the females, and the Sitaris larvae jump on to them, crawl 

 on to the female while pairing, and when that sex deposits its eggs 

 on the honey the larvae spring on the eggs, devour them, then the 

 larvae undergo a change, the eyes disappear, the legs and antennae 

 become rudimentary, they feed on honey, and resemble other beetle 

 larvae. 



It must not, however, possibly be supposed that the development 

 of the individual is an exact record of that of the species. Weis- 

 mann is of opinion that if a character is strongly beneficial to the 

 adult, it has a tendency to be developed earlier in the life-history 

 as time goes on, and it is difficult to believe that changes which 

 profoundly affect the adult do not to some extent affect the embry- 

 onic and immature stages. 



Evolution has to consider not only the physical, but also the 

 mental qualities, and this raises the vexed question of instinct and 

 reason ; what is the difference if they be different ? We must first 

 reject mere reflex action, such as laughter when a person is tickled. 

 Eomanes gives the following definitions : — " Reflex action is non- 

 mental neuro-muscular adjustment due to the inherited mechanism 

 of the nervous system, which is formed to respond to particular, 

 and often recurring stimuli by giving rise to particular movements 

 of an adaptive, though not of an intentional kind. Instinct is 

 reflex action into which there is imported an element of conscious- 

 ness. The term comprises all those faculties of mind which are 

 concerned in conscious and adaptive action antecedent to individual 

 experience, without necessary knowledge of the relation between 

 means employed and ends attained, but similarly performed under 

 similar and frequently recurring circumstances by all individuals of 

 the same species. Reason is concerned in the intentional adapta- 

 tion of means to ends, and may be exercised in adaptation to 

 circumstances novel alike to the experience of the individual and 

 that of the species." I should be inclined to put it in homely 

 language that instinct is the quality which prompts creatures to 

 perform actions consciously, but without experience, learning, or 

 thought, so that they perform them without teaching or conside- 

 ration; and that reason is that which enables them to learn, either 

 from their own experience or teaching, or to exercise thought 



