Vol. XXV ] ENTOMOLOGICAL NEWS 13 



It appears possible to define a species as an aggregation of 

 individuals which in the majority of cases breed together under 

 normal conditions and produce fertile offspring. This seems 

 true, but it is incapable of application with immediate final 

 results in the case of young stocks. The chief difficulty lies in 

 determining what are the limits of the normal fertile variants 

 of species in such stocks. Long series of observations must be 

 carried out to establish the normal self-observed limits of such 

 species in nature. This labor must here often follow instead 

 of preceding a working species-concept, because we need names 

 under which to record our results during the carrying out of 

 the necessary investigations. By the normal self-observed lim- 

 its of species in nature is meant their limits in the long run, 

 divested of exceptions and vacillations. It is useless to attempt 

 to solve such problems merely by the study of dead material. 

 The living phases, functions and environment of the material 

 must be studied as well, and that diligently. 



Thus it is safe to say that each species will have to be worked 

 out eventually on its own merits and standing. As this cannot 

 be done at once, our working concept must be a tentative one 

 that will apply now for such cases. It must be plastic, but of 

 such nature that it will cause no future confusion or perversion 

 of recorded facts that belong with it. How shall we gain the 

 practicable end of a working species-concept for dealing with 

 the forms exhibited by young stocks? It seems that the best 

 way to do this, because the simplest and most thoroughly 

 guarded against error, is to bestow a name upon every form 

 at all abundant in individuals that can be distinguished as dif- 

 ferent from other forms every form that we can sense and 

 characterize as a different form, regardless of the presence or 

 absence of transitional individuals, of interbreeding limits, or 

 of other than an approximate constancy of characters and to 

 consider that form as a tentative restricted species. Such plan 

 will not interfere with the subsequent proper tabulation of 

 forms as subspecies and races, when our knowledge is suffi- 

 ciently complete to warrant it. 



Individual-occurrences should not be confused with form- 



