962 PROTOZOA AND OTHER ANIMALS 



On the other hand, it has been found that certain termites can sur- 

 vive indefinitely on cotton cellulose or a cellulose-lignin complex (Cleve- 

 land, 1925b); and larvae of the rose beetle Potosia cuprea lived for 

 more than six months on filter paper (Werner, 1926). According to 

 Dore and Miller (1923), the wood that is ingested by Teredo navalis 

 loses in the alimentary tract 80 percent of its cellulose, as well as from 

 15 to 56 percent of the hemicellulose, but the amount of lignin is not 

 reduced. Digestion of cellulose undoubtedly occurs in the alimentary 

 tract of many beetles, as, for example, the anobiid Xestobium fufovil- 

 losum (Campbell, 1929; Ripper, 1930) and the cerambycids Hylo- 

 trupes ha]ulus (Faick, 1930), Stromacium julvum, and Macrotoma pal- 

 mata (Mansour and Mansour-Bek, 1933, 1934a). The wood eaten by 

 this last species was found to have very little soluble sugar and starch 

 (0.47 percent). There are many other instances of cellulose digestion 

 among vertebrates and invertebrates. Yonge (1925) published a review 

 of cellulose digestion in invertebrates, but his statement that no cellu- 

 lase has been found in Insecta is not true today. 



yiystrocerca globosa is reported to have a strong amylase, as well as 

 maltase and saccharase, enabling it to make use of the starches and 

 sugars in wood (Mansour and Mansour-Bek, 1934a). Tissue-produced 

 cellulase has been demonstrated in a number of gasteropods and insects. 

 Among xylophagous insects, cellulase appears to be produced by the 

 digestive epithelium of certain cerambycid and anobiid larvae. 



Most cellulose decomposition in nature is brought about by bacteria, 

 filamentous fungi, and certain Protozoa. In many animals that make ulti- 

 mate use of cellulose in nutrition, the material is first acted on by micro- 

 organisms living in the alimentary tract. This is the only method of 

 cellulose breakdown in vertebrates, and it is true also of the process 

 in many invertebrates. Herbivorous mammals harbor bacteria capable 

 of acting on cellulose. Bacillus cellulosam jermentens was isolated by 

 Werner (1926) from larvae of Potosia cuprea, which feed mainly on 

 spruce and pine needles. Bacteria in the intestine of the lamellicorn 

 beetles Oryctus nasicornis and Osmoderma eremita are able to break 

 down cellulose (Wiedemann, 1930). Cleveland et al. (1934) found 

 evidence that symbiotic bacteria are the agents of cellulose decomposi- 

 tion in the xylophagous roach Panesthia javanica. 



In the above-mentioned animals, bacteria dwell in the lumen of the 



