182 L. R. C! EVELAXD. 



GENERAL CONSIDERATIONS. 



i. THE TERMITES. 

 a. Castes. 



In order that the reader, unfamiliar with the nature of a ter- 

 mite colony, may know something of the castes present, the fol- 

 lowing condensed statement (taken from the papers of Snyder 

 and Thompson) is made. In Reticnlitermes flavipes there are 

 five castes, three of which are fertile or reproductive, and two 

 that are sterile or non-reproductive. Males and females occur 

 in each of the five castes. The reproductive castes are: (i) the 

 first form, which has three well-defined phases of development: 



(a) the nymphs, with long wing pads, creamy white body 1.3-1.4 

 mm. long, and light brown eyes; (6) the winged adults, with 

 long wings, dark brown body 6 mm. long, and black eyes; (c] the 

 older males and females, with enlarged abdomens and the scales 

 of the shed wings, body 7-14 mm. long: (2) the second form, 

 which, like the first form, has three well defined phases of devel- 

 opment: (a) the nymphs, with short wing pads and colorless 

 body and eyes; (b) the young adults, with short scaly wing ves- 

 tiges, straw-colored or grayish body 6-7 mm. long; (c) the older 

 adults, with wing vestiges, enlarged abdomen, body length 7-12 

 mm: (3) the third form, which also has three developmental 

 phases: (a) the nymphs, wingless, with white head and body, 

 and eyes that are invisible in the living or unstained specimen; 



(b) the young adults, wingless, head and body pure white, opaque 

 and not transparent, about 6 mm. long; (c} the older adults, with 

 enlarged abdomen, wingless, heiid and body white, 7-9 mm. 

 long. The other castes, the sterile castes, are: (4) the worker, 

 wingless with grayish abdomen, only two developmental phases, 

 i.e., nymphs and adults, always feeds on wood and there is no 

 degeneration of the jaw muscles, always harbors protozoa once 

 an infestation has been acquired, salivary glands small and very 

 little fatty tissue is present in the body; (5) soldier, wingless with 

 elongated head cove ml with thick yellowish chitin, mandibles 

 dark brown long slender and curved, abdomen shorter than in 

 other castes and more flattened, nymphs and adults only, no 

 post adult growth. 



Thompson (1917) showed that the newly halt lu-<l nymphs of 



