STRUCTURE, GROWTH AND ECONOMICS OF INSECTS 



69 



the Species Catalogue — and an Experiment Record of the experiments 

 that are conducted should be kept. The Loose-leaf filing system is one 

 that is admirably adapted for these purposes. 



The observational notes are best made on separate detachable slips 

 of a note book that can be conveniently carried in the pocket. These 

 slips are torn off and filed in card index trays under the name of the 

 insect discussed. This method saves unnecessary transcribing, is 





Fig, 49. — A large breeding cage used in the study of locusts, army worms, etc. 

 {Photo by J, J. Davis.) 



simple, and serviceable in matters of correspondence and the prep- 

 aration of reports and bulletins. 



Three types of collections should be made: (i) the reference collec- 

 tion in standard cases such as the Schmitt, the Comstock or other form 

 of box in which the specimens are arranged in systematic order accord- 

 ing to the latest check lists; (2) the economic collection where the speci- 

 mens are arranged according to host, where the life-stages and the work 

 of the insect are given prominence; and (3) the illustrative collection 

 in Riker mounts for lecture purposes. 



