Problem of nutrition
Termites have notably solved once and for all, and more perfectly and more scientifically than any other animal - with the possible exception of certain kinds of fish - the essential problem of life, namely, the problem of nutrition. Termites feed exclusively on cellulose which, with the exception of minerals, is the most widely distributed substance on our earth, inasmuch as it constitutes the solid part, the framework, of all growing matter.
He first ascertained that, of all animals that have been under observation, xylophagous termites possess the most varied and the most numerous intestinal fauna. Its entrails are literally crammed with four kinds of flagellated protozoa, these being, in order of their size, the Trichonym-pha Campanula, which swarms in millions, the Leidyopsis Sphoerica, the Tyichomonas and the Streblomastix Strix. They are found in no other animal. But if its protozoa be restored to it before the fatal date, it goes on living indefinitely.'
According to Cleveland's experiments, Trichonympha and Leidyopsis both allow their host to live indefinitely, but Trichomonas, when alone, does not enable it to live for more than sixty or seventy days. If Trichonympha and Leidyopsis both disappear, Trichomonas partly makes up for their absence.
These interesting experiments were made upon the big Pacific termite: Termopsis Nevadensis Hagen. Their method of fixing the atmospheric nitrogen which they require to manufacture their proteins, and of transforming the carbohydrates into proteins, is a problem that has not yet been solved. For example, after six days' fasting Trichonympha Campanula perishes, the other three survive: after eight days Leidyopsis Sphoerica succumbs : after twenty-four hours' oxygenation, Trichomonas dies, whereas the other three hold out, and so forth.
When the termites forsake their native city to emigrate or found a new colony, they are careful always to carry with them a certain number of these mushrooms, or at least of their conidia, which are the reproductive cells.
The termites of today are still able to digest, unaided, the mould which, as we know, consists of vegetable matter in decomposition or already digested by bacteria. Cleveland conjectures that, whilst feeding on vegetable mould, they were at the same time absorbing particles of wood containing protozoa, which multiplied and accustomed them to exclusive xylophagy. This is undoubtedly what man would have done in their place. Thenceforward they proceeded systematically to cultivate these cryptogams. they are able to eliminate all other kinds springing up in their gardens, and tolerate only two varieties, the Agaric and the Xylaria, which are admittedly the best.