INTESTINAL PROTOZOA OF TERMITES. 213 



highly probable that the protozoa aid their host in the digestion 

 of pure cellulose and wood, since the host is able to live indefi- 

 nitely on either of these substances only when it harbors the 

 proto/oa. Hut how do the protozoa aid their host in the digestion 

 of wood;-' Mechanic. illy, or by furnishing enzymes, as suggested 

 above, which the ho-t it -elf does not possess. 



I- i- [io--il.li- that tlu- protozoa mechanically aid their host 

 -ince the intestine i- completely gorged with them. The intestinal 

 <e!l- o| the termite in rete enzymes such as cellulase and 



<ellobia-e. only when stimulated by actual contact with vast 

 number- o| inte-tinal pn>to/o.i. 1'avlovsky and Zarin (l<>j_ 



inly of the ferment- in the alimentary canal of the bee. Apis 

 nii-llifcru, found c.ttalase in the stomach and large intestine in 

 winter onl\ Phree hours after the first flight in spring, r. 

 \va- pre-eiii in a very small amount, and two days later, not a 

 i race \\ a- lilt. The-e authors claim that the discharge of catala-e 

 in i he rectum depends upon the accumulation of feces in it 

 during hibernal ion. The l>ee has no need for this enzyme except 

 during hibernal ion, when it seems to regulate the different < 

 di/iiu; pr- and <1< - the surplus peroxides as they ac- 



cimiulate. The production of any en/yme may be explained 

 either .1- a "hunger phenomenon" or due to favorable conditions 

 I nutrition, the latter being, perhaps, the better explanation. 

 You:.. [918 .in hi- \\ork on inulase, showed that stimulation to 

 iucre.i-eil production of this enzyme was dependent upon a 

 direct chemical -timuliis - ub-t a nces present in the medium. It 

 ha- been imp. --ible to extract cellulase or cellobiase from either 

 those termites harboring protozoa or those not harboring proto, 

 delaunated termiti-- . lYin^-heim (1912) claims that cellulase 

 i- an endc .-en/\ me and i- <1 from the cell when stimulated 



b\ direct contact with cellulose. This perhaps explains my ex- 



l ractimi failu: 



The other way the proto/...i may aid their host is to dige.-t the 

 \\ood for it. Sin, i- it ha- been shown that defaunated termites 

 cannot dii^e-t \\ood. the ex[>eriments of Buscalioni and Comes 

 MHO , \\here t he-e in\ e-t i ^ators demonstrated that the wood 

 particles iu-e-ted by the protozoa are digested, are now of -reat 

 value, though thcv \\ere worthless so long as it was not kno-\\ n 

 that the host could not digest wood without the protozoa. There 



