into the entrance and back out “as if afraid.  Another, more heedless, would open “the door and walk in; but it was no sooner in than “it manifested alarm, drew in its feet and antennae, and closed its shell.”  Larvae, apparently of gnats, when “feeding near the entrance, are pretty certain “to run their heads into the net, whence there is no “retreat.  A large larva is sometimes three or four “hours in being swallowed, the process bringing to

* ‘New York Tribune,’ reprinted in the ‘Gard.  Chron.’ 1875, p. 303. [page 409]

“mind what I have witnessed when a small snake “makes a large frog its victim.”  But as the valve does not appear to be in the least irritable, the slow swallowing process must be the effect of the onward movement of the larva.

It is difficult to conjecture what can attract so many creatures, animal- and vegetable-feeding crustaceans, worms, tardigrades, and various larvae, to enter the bladders.  Mrs. Treat says that the larvae just referred to are vegetable-feeders, and seem to have a special liking for the long bristles round the valve, but this taste will not account for the entrance of animal-feeding crustaceans.  Perhaps small aquatic animals habitually try to enter every small crevice, like that between the valve and collar, in search of food or protection.  It is not probable that the remarkable transparency of the valve is an accidental circumstance, and the spot of light thus formed may serve as a guide.  The long bristles round the entrance apparently serve for the same purpose.  I believe that this is the case, because the bladders of some epiphytic and marsh species of Utricularia which live embedded either in entangled vegetation or in mud, have no bristles round the entrance, and these under such conditions would be of no service as a guide.  Nevertheless, with these epiphytic and marsh species, two pairs of bristles project from the surface of the valve, as in the aquatic species; and their use probably is to prevent too large animals from trying to force an entrance into the bladder, thus rupturing orifice.

As under favourable circumstances most of the bladders succeed in securing prey, in one case as many as ten crustaceans;—­as the valve is so well fitted to [page 410] allow animals to enter and to prevent their escape;—­and as the inside of the bladder presents so singular a structure, clothed with innumerable quadrifid and bifid processes, it is impossible to doubt that the plant has been specially adapted for securing prey.  From the analogy of Pinguicula, belonging to the same family, I naturally expected that the bladders would have digested their prey; but this is not the case, and there are no glands fitted for secreting the proper fluid.  Nevertheless, in order to test their power of digestion, minute fragments of roast meat, three small cubes of albumen, and three of cartilage, were pushed through the orifice into the bladders of vigorous plants.  They were