596 ANNUAL REPORT SMITHSONIAlSr INSTITUTION^ 1916. 



A step further and we come to pure Lamarckism, to the inheri- 

 tance of habits acquired by experience. Like many other predators, 

 the yellow-winged Sphex hollows out its burrow before starting on 

 the chase, then returning with the prey, places it on the edge of the 

 hole to make a last visit to his domicile. If the prey be moved a 

 little distance, the wasp on coming out of the hole, hunts it up, brings 

 it back to the edge of the hole and again begins a visit. This is 

 the mechanism of instinct. " One after another, as many as forty 

 times, I have repeated the same experiment on the same individual," 

 reports Fabre, " and its persistence was greater than my own, its 

 tactics never varied." But in a group studied the following year the 

 Sphex were less stupid; after two or three experiments they frus- 

 trated the deceit and entered their home with the game. " What 

 would you say to this?" he demanded. "The tribe that I examine 

 to-day, the issue of another stock, for the offspring return to the home 

 selected by the previous generation, is more skillful than the tribe 

 of last year. The knowledge of craftiness is transmitted; some 

 tribes are more skillful and some more stupid, apparently following 

 the faculties of their fathers." Here we are well on the tlii-eshold 

 of Lamarckism, for these better gifted individuals have learned 

 from experience to be on their guard against an accident which 

 would not be rare under natural conditions. 



It seems now to be well established that the psychic evolution has 

 been and is still effected in two ways: By short jumps or mutations, 

 and slowly, by experience; heredity, in both cases, fixing the new 

 habits which then take the automatic form of instincts. In spite of 

 his ideas on unchangeable instinct Fabre has contributed more than 

 any other man to making known the mechanism of the phenomena 

 of evolution. Through the charm that he knew how to give to his 

 observations he has raised up in all countries a host of eager investi- 

 gators who admire him without adopting his belief. Through his 

 exhaustive criticisms sustained by minutely controlled facts he kept 

 evolutionists busy and has prevented them from resting on the laurels 

 of the great masters who established the theory ; finally by his works 

 themselves he was one of the artisans who contributed the most to 

 prove this last. 



More profound than Reaumur and with a charm which Reaumur 

 lacked Fabre has exerted and will long exert an influence equally 

 great. He was a professor in the highest meaning of the term, and, 

 moreover, a teacher of an entirely special kind, who dwelt alone and 

 raised up followers by the magic of his style, the powerful interest 

 of his works. In that as in all things is seen a perfect originality 

 and of the highest standard. His sympathetic biographer, Dr. Legros 

 has justly written of him, "He owed little to others, savants or 



