PKKSIDENTIAL ADDRESS — SECTION D. 99 



ing to the termite-coninumity. When little or no. external 

 modification of the termitophile can l)e noticed the friendly re- 

 lationship is probably associated with the production of an 

 agreeable scent by certain abdominal intersegmental glands. 



A. Exudatory Organs of Termitophiles. — In the higher 

 lype of termitophile. exudatory organs are produced (Plate 9), 

 and there is a remarkable similarity or convergence 

 in these structures in widely different arthropods. That 

 these structures actually exude a fluid, which is licked 

 up by the termites, is rendered extremely probable by 

 W'heeler's* interesting observations on certain ant-larvae in 

 which thin-walled outgrowths of the anterior portion of the 

 body exude a fluid that is eagerly absorbed by the nurses. One 

 of the simpler types of exudatory structures is seen in certain 

 beetle larvje (Plate 9, A, B), where the abdominal segments 

 exhibit blunt, thin-walled, lateral swellings, arranged symmetri- 

 cally in pairs. In the imago beetle we may find, as in Paracoro- 

 toca'\ (Plate 10, K), a small median, dorsal swelling between 

 the pronotum and the head, and two larger, lateral swellings as 

 posterior outgrowths from the metathorax. 



A similar, segmentally arranged series of outgrowths, but 

 more conspicuously developed, is seen in Tragardh's tineid larva 

 (PI. 9, Fig. C), and the termitophile at first sight resembles a 

 centipede. In another closely similar tineid larva from (he Congo, 

 described by \\''asmann, the 7 paired processes are longer and are 

 very definitely jointed (D, E). Again, in a dipterous larva (F) 

 irom Madagascar, also described by Wasmann, there are eight 

 pairs of many jointed processes springing from the segments. 

 Recently Mr. Claude Fuller has sent to me an allied larva from 

 the Transvaal, in which the processes are mostly 7-jointed. and 

 are arranged in a whorl on each of eight segments (G). These 

 processes of the dipterous larva closely resemble those of the 

 lepidopterous larva from the Congo {cf. H, E). Jointed exuda- 

 tory organs arising from the abdomen of the termitophilous 

 lieetle, Spirachtlia, were described and figured by Schiodte. 



I have carefully examined sections of these exudatory 

 structures of the beetle Paracorotoca, of the supposed beetle- 

 larva of the same, of the tineid-Iarva, and of the dipterous larva, 

 and in no case have I detected definite pores in the cuticle. The 

 cavity of the structures was filled with blood only, or with 

 blood and a certain amount of fat-tissue in addition. In the 

 case of the jointed processes of the fly-larva the cuticle was 

 thick, but very distinctly soft and fibrous in character. There 

 is no doubt that considerable diversity in the nature of chitin 

 occurs, and that some varieites, when pores are absent, are far 

 more permeable to fluids than is generally supposed. 



* Proc. of the American Philosophical Society. 57 [4] (1918). 

 ■\ Paracorotoca akcrmani (Warren)=Corofcra akermani Warren. 



