386 ENTOMOLOGICAL SOCIETY 



less excuse for the cumbering and befogging of the literature 

 which has resulted from careless, hasty, and thoughtless work. 



Minute differences in the pores or glands and appendages, or 

 in the lengths of the joints of antennas or legs, are usually indi 

 vidual and would often make two species of the same specimen 

 if the latter were cut in half in the line of the main axis of the 

 body. To return to an illustration already employed, one might 

 as well describe men as distinct because they have Roman or 

 Greek noses or short or long chins. 



In other groups than the Diaspinas, I cannot speak from care 

 ful personal study, but I have the gravest doubts of the value of 

 descriptions based on slight variation in the lengths of the joints 

 of legs and antennas, all of which must be subject, within specific 

 limits, to variation with the age of the specimen and with its con 

 dition as to abundance or scarcity of nourishment. In this con 

 nection I cannot do better than quote the views expressed rela 

 tive to the group Lecaniinas by Mr. Pergande in a recent letter 

 to a correspondent, views in which I heartily concur. He says : 



" With regard to the difference in length of one or the other 

 of the antennal joints, * * * I will say that it is simply in 

 dividual variation ; even in the same specimens the comparative 

 length of either of the joints of both antennas varies frequently 

 more or less. There is generally also a more or less perceptible 

 variation in size, color, and shape in the same species, dependent 

 in a measure on the food plant on which it may have established 

 itself and also on the locality. Old specimens, which have at 

 tained their full growth and have died a natural death, are gener 

 ally darker, if prepared for the microscope, than younger indi 

 viduals of the same stage and with all the pores of the derm much 

 more distinct. As to the shape of the individual scales and their 

 sculpturing, I find in our material of typical specimens of Lee. 

 armeniacum the same variations as those mentioned * * *. 

 To consider every slight variation of specific value, would lead to 

 endless species which nobody would be able to recognize, and 

 which would cause endless trouble in the study of this most dif 

 ficult group of scale insects." 



The writer trusts that the foregoing criticisms will be taken in 

 the kindest spirit as tliey are intended, and he does not wish it to 

 be thought for an instant that he fails to recognize the learning 

 and enthusiasm shown by the prominent workers in theCoccinas, 

 by no means all of whom have been equally guilty, and whose 

 work in the main has been most excellent.and commands the 

 heartiest approval, but having experienced the great difficulty 

 and labor necessary to discover and correct errors arising from the 

 conditions criticised, the need of calling attention to them seems 

 imperative. 



