254 MR. B. ¥. f'UMMIXGS OX LICE 



spirit-specimens is not essential for systematic study ; while in 

 many groups, such as those here considered and the Ephe- 

 meridae, pinned or carded material is for the purposes of study 

 almost worthless. Another portent is the obsolescence of the 

 short, superficial Latin diagnosis in the description of new 

 species^the persistent remains of the early influence of the 

 schoolmen on systematic zoology. In some quarters the super- 

 ficial diagnosis is already swept into limbo Avith the Sedan 

 chair — both of them vehicles which could not possibly take us 

 far, as traffic runs nowadays. 



As precis work the superficial diagnosis is admirable. A 

 certain number of characters from a certain restricted area 

 of an animal's anatomy (as a rule, the easily accessible external 

 parts) are selected and then welded into a cast-iron paragraph 

 as exact and inflexible as a lawyer's deed-poll. But in ento- 

 mology, as in politics, the lawyer is a strong but undesirable 

 element, and the only justification for the superficial diagnosis is 

 that the descriptive writer sometimes may find it convenient as 

 a summary to tag on to the end of a long description. 



The systematist is primai-ily a morphologist whose task it is 

 to discover the true phylogenetic relationships, at least between 

 the small subdivisions such as genera, and species. This is a 

 responsible task, especially in entomology, requiring the dis- 

 section, careful morphological examination, and description of 

 each species. Many characters which have to be dissected to be 

 seen are already in use among systematic entomologists, e. g., 

 the male genitalia, the spermatheca, the mouth-parts, and endo- 

 skeleton. It is not suggested, of course, that internal or con- 

 cealed characters are necessarily better than external ones. 

 What are the best characters for systematic use is a question 

 which has to be investigated and settled for each individual 

 group of the Animal Kingdom. Quite recently Dr. P, Chalmers 

 Mitchell wrote * ; — " The more experience I gain of avian 

 anatomy, the more I am convinced that systematists are well 

 advised when they rely, at least with regard to the discrimination 

 of species and genera,, more upon those superficial characters 

 that they can observe in the series of museum collections than 

 on the uncertain indications afforded by the presence or absence 

 of this or that muscle." 



Yet, how many systematists have conscientiously gone through 

 the anatomy of their group with a view to settling this fundamental 

 question of the best combination of characters for the purposes 

 of classification (for I imagine that single-character classification, 

 such as Huxlej^'s palate and Garrod's ambiens among birds is now 

 discredited). The descriptive writer is an opportunist who, as a 

 rule, seizes upon the most convenient characters that offer them- 

 selves. Certainly, it is in entomological opportunism that we 

 must seek the cau.se of the present systematic disoi-der among the 



* P. Z. S. It)l5, IK 413. 



