376 



and what is true of tliein is, I believe, true of all alliances of orgauisms. 

 The first and most important is structural and generic; it is ab.solutely 

 essential and is preserved in its perfection by the elimiuation, through 

 natural selection, of all forms departing from it. The second is merely 

 coincident, not essential, but nevertheless along lines that are of sec- 

 ondary advantage. The third is purely fortuitous, affects superficial 

 features in the main, is unessential (a consequence of the inherent ten- 

 dency of all things to vary), and takes place along all lines and in all 

 directions where there is no counteracting resistance. 



TRANSMISSION OF CHARACTERS THROUGH HEREDITY. 



N^ow, when it comes to the bearing which the history of these little 

 moths has upon some of the larger questions that are now concerning 

 naturalists (for instance, the transmission of acquired characters, or the 

 origin, development, and nature of the intelligence displayed by the 

 lower animals), broad fields of interesting opinion and conclusion open 

 up before ns — fields that can not possibly be explored without trenching 

 too much upon your time. I will close, therefore, with a few summary 

 expressions of individual opinion, without attempting to elaborate the 

 reasons in detail, and with the object of eliciting further discussion, 

 which is one of the objects of this paper. My first conviction is that in- 

 sect life and development give no countenance to the Weissmann school, 

 which denies the transmission of functionally acquired characters, but 

 that, on the contrary, they furnish the strongest refutation of the views 

 urged by Weissmann and hisfollowers. The little moths of which I have 

 been speaking, and indeed the great majority of insects, all, in fact, 

 except the truly social species, porforin their humble parts in the econ- 

 omy of nature without teaching or example, for they are, for the most 

 part, born orphans, and without relatives having experience to com- 

 municate. The progeny of each year begins its independent cycle anew. 

 Yet every individual performs more or less perfectly its allotted part, 

 as did its ancestors for generation after generation. The correct view 

 of the matter, and one which completely refutes the old teleological 

 idea of the fixity of instinct, is that a certain number of individuals are, 

 in point of fact, constantly departing from the lines of action and varia- 

 tion most useful to the species, and that these are the individuals which 

 fail to perpetuate their kind and become eliminated through the general 

 law of natural selection. 



Whether these actions be purely unconscious and automatic or more 

 or less intelligent and conscious does not alter the fact that they are 

 necessarily inherited. The habits and qualities that have been ac- 

 quired by the individuals of each generation could have become fixed 

 in no other way than through heredity. Many of these acts, which 

 older naturalists explained by that evasive word " instinctive," maybe 

 the mere unconscious outcome of organization, comparable to vegetative 

 growth; but insects exhibit all degrees of intelligence in their habits 



