966 PROTOZOA AND OTHER ANIMALS 



found to have cellulase, and it is in that higher group that one might 

 be most Hkely to find the enzyme. 



The literature on this subject, so far as the writer has determined, 

 contains no discussion of the hemicellulase lichenase, which UUmann 

 (1932) reported to occur in all the insects, including roaches, and the 

 snails that he tested; and which Oppenheimer (1925) stated is wide- 

 spread in invertebrates. Montaienti (1932) wrote that in the fore-gut 

 of K. flavicollis he found a trace of amylase, which was probably pres- 

 ent in the salivary secretion; in the mid-gut, amylase and invertase, as 

 well as a protease that acted only in acid, though the mid-gut is basic; 

 and in the hind-gut, amylase and invertase probably derived from the 

 mid-gut. Hungate (1938) found amylase in an extract of the fore-gut, 

 and protease in the mid-gut of Zootermopsis angusticollis. On the basis 

 of these findings, it should be possible for the termites to hydrolyze 

 starch; to invert sucrose; to digest the small amount of protein in wood 

 and possibly also some of their own micro5rganisms, when the resistance 

 of the latter to the enzyme has been overcome. 



As remarked above, bacteria in many cellulose-utilizing animals are 

 necessary for the preliminary breakdown of cellulose. Cleveland et d. 

 (1934) suggested the possibility that some Termitidae may profit from 

 the presence of bacteria in the same way. But in those termites that have 

 been examined for cellulose-decomposing bacteria, it appears that the 

 latter cannot account for cellulose digestion. A few positive results have 

 been obtained. Dickman (1931) found them in one of six nitrate- 

 cellulose tubes inoculated with gut contents of ReticuUtermes flavipes, 

 and Tetrault and Weis (1937) obtained some from the same termite; 

 but Cleveland (1924) failed in many and varied attempts to isolate 

 cellulose-decomposing bacteria or other fungi from R. flavipes. Beck- 

 with and Rose (1929), using termites of six genera, including one of 

 the Termitidae, obtained cellulose-digesting bacteria in some instances, 

 but not at all in two species. Their results, however, are subject to 

 criticism (Dickman, 1931; Hungate, 1936). Hungate (1936) was un- 

 successful in efforts to show cellulose decomposition by bacteria from 

 the gut of Z. nevadensis, and concluded that bacteria in the alimentary 

 tract are of no importance in the digestion of cellulose. A possible ex- 

 planation of the occasional positive tests is found in Cleveland's dis- 

 covery that in Cryptocercus punctulatus, feeding on its normal diet of 



