20 ENTOMOLOGICAL SOCIETY 



character or power of immediate advantage is already sufficiently 

 pronounced to be of use. But after progressive modification with 

 out selection has carried a new feature to the point of utility, it 

 seems gratuitous to predicate another agency as necessary for its 

 further accentuation. 



Instead of nicely balanced opposing principles, heredity and 

 variation may prove to be merely two aspects of the same process 

 of gradual change. Organisms react, within limits, to external 

 conditions, some being more adaptive or more plastic than others ; 

 they also acquire new characters with greater or less rapidity, but 

 it is not necessary to insist upon any causal connection between 

 these two facts. In some senses acquired characters are heredi 

 tary, but it is not necessary, on the one hand, to believe that they 

 originate from external causes, or, on the other hand, that they 

 are predetermined by an inflexible principle of development. Of 

 course, there are other senses in which it is true that no charac 

 ters are inherited, only tendencies and potentialities, but this does 

 not alter the case when a series of individuals is viewed as a seg 

 ment of the evolutionary progress of a species. 



The history of the individual, like that of the race, variety, or 

 species, shows a process of continuous change or progressive 

 evolution which proceeds in spite of uniformity of environment. 

 Isolation, whether geographical or due to selection or domestica 

 tion, may influence the direction and rate, but is in no proper 

 sense a cause of the motion. 



MAY 9, 1901. 



The i6ist regular meeting was held at the residence of Mr. John 

 D. Patten, 3033 P street N.W., the chair being occupied, in the 

 absence of the President and both Vice-Presidents, by Dr. Gill. 

 The others present were Messrs Ashmead, Chapin, Barber, 

 Busck, Howard, Morris, Kotinsky, Patten, Currie, and Sander 

 son. 



Mr. Morris called the attention of the Society to the public ex 

 hibition, soon to be held, of the botanical and zoological work of 

 the Washington high schools. 



Under Short Notes, Dr. Howard spoke of the many inventions 

 for trapping insects at light recorded at the U. S. Patent Office, 

 mentioning in particuhir one such device being mimufactured in 

 large quantities by a man <-it Hazeltine, Missouri, for destroying 

 the Codling Moth. He regarded the statistics concerning insects 



