296 LIFE AND HABIT. 



of life and species should be, on the hypothesis that 

 they were mainly due to memory. 



I think I may say that we found the hypothesis fit in 

 with' actual facts in a sufficiently satisfactory manner. 

 We found not a few matters, as, for example, the sterility 

 of hybrids, the phenomena of old age, and puberty as 

 generally near the end of development, explain them- 

 selves with more completeness than I have yet heard of 

 their being explained on any other hypothesis. 



We considered the most important difficulty in the 

 way of instinct as hereditary habit, namely, the struc- 

 ture and instincts of neuter insects; these are very 

 unlike those of their parents, and cannot apparently 

 be transmitted to offspring by individuals of the pre- 

 vious generation, in whom such structure and instincts 

 appeared, inasmuch as these creatures are sterile. I do 

 not say that the difficulty is wholly removed, inasmuch 

 as some obscurity must be admitted to remain as to 

 the manner in which the structure of the larva is 

 aborted ; this obscurity is likely to remain till we know 

 more of the early history of civilisation among bees 

 than I can find that we know at present ; but I believe 

 the difficulty was reduced to such proportions as to 

 make it little likely to be felt in comparison with that 

 of attributing instinct to any other cause than inherited 

 habit, or inherited habit modified by changed conditions. 



We then inquired what was the great principle under- 

 lying variation, and answered, with Lamarck, that it 

 must be "^ sense of n eed;" and though not without 

 being haunted by suspicion of a vicious circle, and also 

 well aware that we were not much nearer the origin of 



