278 ENTOMOLOGICAL NEWS. [Nov., '02 



Among domestic animals, some individuals are slow and delib- 

 erate, others quick and impatient. Some feed freely upon 

 articles of food that will be avoided by other individuals. 

 Birds are known to have individual likes and dislikes. No 

 one who has reared insect larvae to the adult, has failed to 

 observe the difference in the individual temperament of the 

 several members of the family. Some will be quiet and docile 

 so to speak, while others will be iritable and uneasy. In a 

 most excellent series of papers on " The Wanderings of In- 

 sects," Professor Karl Sajo has justly remarked that, among 

 insects, there will be some individuals of the same species that 

 will be wanderers while others will be stay-at-homes. Among 

 the Hymenopterous enemies of other insects, while there are 

 some species that appear to be generally parasitic on other 

 in.sects, the majority are more exclusive in their hosts, and 

 particular genera will be found parasitic on another, or on 

 another family, so that, knowing the species of a parasite, we 

 can determine at once the order and not unfrequently the 

 family or genus to which, the host insect belongs. But even 

 here, it is still to be proven that there are not individual ex- 

 ceptions ; it is by exceptions that nature frequently protects 

 from extermination. And, it is here as elsewhere, we only 

 know what we s^e, and while on this basis we may form a 

 good idea of the nature of effects that will follow certain causes, 

 we mu.st not lo.se .sight of the fact that there are exceptions to 

 everything — except death itself. For this reason, a single ob- 

 servation on the habits of an insect, bird or animal is worth ju.st 

 that much ; it may be the one out of a hundred or even thou- 

 .sand exceptions. Therefore, I wish it to be clearly understood 

 that I do not wisli to depreciate the value of isolated observa- 

 tions, but to point out the very great need of further investi- 

 gation with .several individuals, in order to be sure that it is 

 the rule and not the excei)ti()n that we have ob.served, and this 

 is quite apropos to the criticism of dui)lication of work, that 

 is frequently offered. The so-called duplication, is not in any 

 .scn.se coni])ilation, and if an observation is honestly made and 

 correctly recorded, it is never without value, and fre(|uently it 

 is the one thing necessary to an accurate conclusion, W'e have 



