XX. Proceedings. \^March 6th, igij. 



devouring the fact-body, and labsorbing the oxygen of the blood- 

 plesma, atrophy of the gonads resuhs; (5) The lefifects of the larvae 

 of the dryinid hymenopterun Aphelopus, and those of the pipun- 

 cuhid fly Chalarus, upon leaf-hoppers of the genus 2'yphlocyba ; 

 (6) The supposed occurrence of " castration-parasitaire " among 

 Termites. Grassi and Sandias (1893) pointed out that, in certain 

 Itahan Termitids, the soldiers and workers harbour vast num- 

 bers of Pro(tozoa in the specially enlarged hind intestine. In 

 Termites infected with these Protozoa the gonads are very greatly 

 reduced an-d the sexual function lost. In the very young larvae, 

 and the sexual form,s, which are feid on saliva, the Protozoa are 

 absent. These zoologists regard /the development of the sterile 

 soldier and worker castes are 'being correlated with infection by 

 piarasitic Protozoa. Brunelli (1905) regards this as a case of 

 "castration-parasitaire," and says that (jn certain queen Termites 

 which he examined Protozoa, were present, and the ovarie's of 

 their hosts were degenerating. This conclusion has been dis- 

 puted recently by Feytaud, who states that the appearances of 

 tihe oyJaries, w'hich Brunelli interprets as being indicative of 

 degeneratioin, are in reality only artifacts resulting from the re- 

 agents ■employed. Dr. Imms then dealt with his own researches 

 which were conducted on the Himalayan Termite Archoter- 

 'mopsls. In this primitive form, the gonads in the so-called 

 sterile castes, are as well developed as in the sexual forms, never- 

 theless Protozoa are e.xtremely abundant in the hind intestine in 

 every instance. They were also found in the gut of the sexual 

 fdrnxs on several occasi(ons, ;a;nd were, furthermore, present in 

 g!rieat qua,ntiities in ah iegg-layin^g worker-like individual. Dr. 

 Imms pointed out that the evidence was in favour of the Pro- 

 tozoa not being parasites at all, and that very possibly they were 

 symbiotic in their relations with their host. It is a significant 

 fact that, so far, they are only known to occur in the intestine of 

 wood-feeding Termites, and there is good reason to believe that 

 these minute organisms act upon the lig"nin in their digestive pro- 

 cesses, and render it capable of ready assimilation by the host 

 Termites. The Protozoa appear to have no influence at all upon 

 caste production, as soldiers and workers are ^ present in numerous 

 Termites which do nojt harbour these organisms. Similarly they 

 exert no apparent influenjce on the gonads, as can be readily seen 

 in Archotermopsis, Ei/fer//ies. and other forms. In the first- 

 named genus the gonads are highly developed, and Protozoa 

 occur in prodigious numbers, while in certain species of Etilermes 

 Protozoa are totally wanting, nevertheless the gonads are so 

 degenerate as to be almost absent. In conclusion, Dr. Imms re- 

 ferred briefly to the presence of Infusoria in the digestive system 

 of the Ruminantia and Equidae, and to their possible symbiotic 

 role as agents, which render the cellulose of the food capable of 

 being digested by these animals. 



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