June, '09] 



JOURNAL OF ECONOMIC ENTOMOLOGY 



229 



intensity of stimulation, i. e., an examination of the following table 

 reveals the fact that Lucilia ccesar is a fly wliich is more reactive to 

 light in the larval stage than is CalUphora vomitoria, which was also 

 experimentally shown for the adults. 



TABLE 2 



Reactiveness to directive light through the general range of intensity for 

 migrated larvae of Lucilia caesar (Lots No. 6 (A) and No. 25 B), and of Calliphora 

 vomitoria, (Lot No. 24.) ^ 



REACTIONS 



It should be explained that the study of the flesh-flies was under- 

 taken by the writer ^- because of their importance as scavengers of 

 lake beach debris, and were used later as favorable organisms for 

 detailed observation with regard to light reactions.*^ 



In conclusion I cannot refrain from expressing my regret that there 

 are students of animal behavior who know only the laboratory aspect 

 of animals, who seem to believe that it is unbecoming to carry on 

 field observations. Plucking an animal from its native soil without a 

 thought of its natural environment and hustling it into the laboratory 

 and subjecting it there to all manner of stimuli, often of unknown 

 intensity and quality, is certainly not a commendable method of pro- 

 cedure. The normal environment and normal behavior of an or- 

 ganism should have the experimentor's closest attention, in order to 

 aid in a correct interpretation of the phenomena observed under 

 experimental conditions. A combination of field and laboratory 



^The reactions (P. N. I. = positive, negative and indifferent respectively) are 

 based on the movements of ten larvae given five trials each at an exposure of 

 thirty seconds. Between trials, taking larvae No. 1 first, then No. 2, etc., 

 through the series, each individual was kept separate in a closed receptacle. 



