The sublingual gland is inert during mastication, and only begins to act as swallowing commences, when it envelops or lubricates the chewed substance with a fluid that assists its passage to the stomach. The function of the submaxillary has much to do with taste; the fluid which it pours out dilutes and diminishes the pungent flavour of sapid substances, and at the same time weakens the energy of their contact. The three organs are identical in texture, though so different in their secretions; 'each gland,' as M. Bernard says, 'having a special act, its function is exercised under separate and independent influences. Notwithstanding their discharging into and mixing in the mouth, their use remains distinct,' as above stated. To complete this brief summary of an interesting subject, it may be added, that birds and reptiles have but one kind of saliva, answering to the viscous in mammalia.
M. Vogt, in a communication to the Académie, adds to the proofs that what is called the spontaneous generation of certain worms, is due to natural causes. For instance, a worm, which has no reproductive organs, is often found in the body of the stickle-back; this worm, however, is known to breed, but it does so only when the stickle-back happens to be eaten by a bird; the worm is then placed in the proper condition for development, 'for it is then only that its segments become filled with eggs, which, egested by the bird, pass into the bodies of other fishes;' in a way more in accordance with natural operations than spontaneous generation.
Again, of two kinds of worms which infest human beings, the _Bothriocephalus_ is found among the Poles, Swiss, and Dutch, while the _Tenia_, or tape-worm, is common among the French and Germans. If, however, the latter reside in Switzerland, they also become infested with the first-named worm, the reason given being, that in Switzerland liquid _excretæ_ from cesspools are largely used for manuring vegetables, and that, in the eating of these vegetables, the eggs of the worms are taken into the body, and become hatched by means of the intestinal warmth. These investigations, which are to be continued, are important, seeing that they have a bearing on the phenomena of health and disease.