Cellulose Digestion by the Silverfish Ctenolepisma Lineata *

Abstract

It is the prevailing opinion to-day that the majority of species of animals which feed upon plants or plant products are unable to hydrolyse cellulose in spite of its abundance (Baldwin, 1952), depending instead upon the sugars, starches, fats and proteins present in the plant tissues. This implies the lack of a suitable alimentary enzyme, cellulase, or symbiotic gut micro-organisms which could perform that function. Study of cellulose digestion in animals is hampered by the difficulty of defining the role of the micro-organisms of the gut. If cellulolytic action is found in extract of tissues or in secretions of glands, the question remains whether or not this activity is attributable to micro-organisms; conversely, finding a cellulose-digesting microbe in the intestine of an animal does not prove conclusively its benefit to the animal.