A third enzyme, the trypsin of the pancreas, possesses the power of both pepsin and erepsin.
This amyloid substance is slowly and imperfectly digested by pepsin - digestion being more complete with trypsin and by autolytic enzymes.
That such enzymes are formed in the protoplasm is evident from the behaviour of hyphae, which have been observed to pierce cell-membranes, the chitinous coats of insects, artificial collodion films and layers of wax, &c. That a fungus can secrete more than one enzyme, according to the materials its hyphae have to attack, has been shown by the extraction of diastase, inulase, trehalase, invertase, maltase, raffinase, malizitase, emulsin, trypsin and lipase from Aspergillus by Bourquelot, and similar events occur in other fungi.
The secretion of trypsin by the pancreas may therefore be looked upon as the formation of a toxin.
We do not know at present if any corresponding anti-toxin or antitrypsin, as we may term it, is returned into the lymphatics or blood from the gland, but the pancreas, which in addition to secreting trypsin secretes a diastatic ferment forming sugar from starch, pours this into the intestine and secretes at the same time a glycolytic ferment which breaks up sugar, and this latter passes into the blood by way of the lymphatics.