Page:Popular Science Monthly Volume 8.djvu/68

58, crustaceans, larvæ, and fresh-water worms, in various stages of decay. The animals enter the bladder by bending in the free edge of the valve, which shuts again instantly. How it is that such weak and minute animals get into the bladders is not yet understood, but they do succeed in entering as do inanimate objects, if laid upon the valve. The locality of the irritability, if indeed there be any, is not determined.



Notwithstanding the elaborate mechanism for the capture of animal food, there seems to be no power of digesting it, nor for hastening its decay; although, when decomposition sets in, its products are slowly absorbed by the quadrifid processes; at least, these processes from bladders containing decayed animals generally show masses of spontaneously-moving protoplasm which do not appear in those taken from clean bladders.

Investigations were extended to many other species of Utricularia, with results showing, in all cases, an adaptation for capturing small animals and power to absorb the products of their decay.

To be classed with this genus, as being insectivorous to a similar extent, are Sarracenia and Darlingtonia. Upon these Mr. Darwin records no observations.