PROCEEDINGS, 1915. 83 



Now in the course of what has been said to-night, there is one point 

 which the amateur is in some danger of misunderstanding. It is this: — 

 When we speak of the moth "imitating" the color and form of the 

 wasp, or the hawk-moth "imitating" a bumble-bee we must un- 

 derstand very clearly that this imitation is by no means conscious effort 

 on their part. How much the lower animals are aware of their protec- 

 tive coloring, is an entirely different matter, but this one thing is certain. 

 No insect has any voluntary control over its form of coloring. How then 

 does it come about that we have such wonderful phenomena, that is, 

 through what forces or. laws does nature mould and keep these almost 

 inviolate types that we have illustrated tonight. 



Right here let me make an apparent digression. It would be a very 

 moderate estimate to say that any of the insects we have spoken of to- 

 night lay at least 100 eggs. Now if these eggs all hatched and the young 

 developed into mature insects we would have one hundred offspring from 

 each pair, or an increase of fifty fold. But since we know that this does 

 not happen, but that the abundance of insects remains about the same 

 from year to year, we see that (even following the very moderate estimate 

 we assumed at first) an insect egg would have about one chance in fifty 

 of coming to maturity and this we are ready to admit is pretty sharp 

 competition. 



But we need not depend upon theoretical evidence alone, to argue 

 the existence of the great and universal war waged by living creatures in 

 the struggle for life. Even an observer of very ordinary calibre cannot 

 remain quiet amid natural surroundings, without seeing on all sides evid- 

 ence of the great and intense warfare that living creatures are making on 

 each other. We see it everywhere, from the minute creature in the drop 

 of stagnant water that pursues the more minute form across the field of 

 the microscope, to the hawk — that drops like a bolt out of the blue upon 

 the unsuspecting victim that has transgressed ever so little into the open. 

 In this universal struggle we realize the first great force by which the 

 types of living forms are moulded. 



Now another apparent digression, and we are done. If we had here 

 hundreds of these tortoise-shell butterflies we would perhaps be struck 

 with the very close resemblance they had for one another. Perhaps there 

 is nothing so wonderful in all nature, that from two minute, almost micro- 

 scopic eggs, deposited by different parents perhaps hundreds of miles 

 apart, there will develop and expand two creatures, so intricate and beau- 

 tiful in pattern, and yet so similar as to appear almost as if stamped with 

 the same die. This is what scientists call "conformity to type." 



And yet if we examined these specimens closely we would find that 

 no two of them would be exactly alike. One would have perhaps a little 

 more white in its pattern than the others, or another would be a little 



