Social Insects. 51 



a prime influence in the origin, through family, clan, tribe and 

 state, of organized civilization; so in the insect world we find 

 the same cori'clation between the highest intelligence and depend- 

 ent infancy, and are justified in concluding that the latter is, in 

 the social Hymenoptera as in man, in the same way the cause 

 of the high organization, and division of labor so charateristic 

 of them ! 



Heredity: ISTatural Selection. 

 The application of the principle of natural selection to the pro- 

 duction of neuter insects, and especially to the j^roduction of 

 neuter insects of diversified form, seems, at first sight, impossi- 

 ble. Indeed, we know that Darwin felt that this question of 

 neuter insects was one of the most difficult to deal with in con- 

 nection with his grand generalization. Weismann, who believes 

 in the all-sufficiency of natural selection, insists, and has within 

 the past year, in his controversies with Herbert Spencer, empha- 

 sized his belief, that these neuter insects absolutely preclude the 

 idea of the transmission of acquired characters, and endeavors to 

 explain their occurance by his own peculiar theories as to modi- 

 fication taking place in the germ plasm. I shall certainly not 

 attempt, in the limited time that I may yet hoi)e to hold your 

 attention, to discuss in detail the views held whether by Weis- 

 mann or his opponents ;* but I will venture to show that, while 



*The chief argument in favor of Weismann 's theory of heredity is that 

 it is an earnest attempt to establish a basis in observed histologic and em- 

 bryologic facts. The idea of the continuity or "immortality" (using the 

 word in his own qualified use of it) of the germ plasm is a bold one which 

 gives us at least a conceivable and material basLS of reproduction, and is 

 justified, though not absolutely, in the facts referred to and in the history 

 of the Protozoa. One of the chief arguments against it is, in my judgment, 

 that, inasmuch as it precludes the transmission of impressions on the soma, i. 

 e., individually acquired characters, Weismann has, in order to sustain the 

 theory, been led to (juestion and finally to deny the transmissibility of such ac- 

 quired characters. It is difficult to formulate the later modifications of the orig- 

 inal theory without using many Weismannisms, themselves requiring chapters 

 of explanation ; but that variation is due to direct effects on the germ plasm 

 by inequalities of nutrition, Ls, I believe, a correct statement of his latest 

 views. The trouble with all theories of reproduction and heredity based 

 solely on observed nncroscopic facts, is that the essence, the life principle, 

 the potential factors, must always escape such methods. Wherefore any 

 theory that will hold must cover the psychical as well as the physical facts 

 — the total of well established experience — and this truth was doubtless 



