in order to ascertain their irritability; it is not even yet well known which is the irritable part of the filaments, and whether it be only their base, as Smith has had the address to discover." In answer to which I need only request any one to read the above account, or the more ample detail in my original paper, and above all, to examine a Barberry-blossom for himself; and if any doubts remain concerning the existence of vegetable irritability, let him read Senebier's whole chapter intended to disprove it, where that candid philosopher, while he expresses his own doubts, has brought together every thing in its favour. Among the whole of his facts nothing is more decisive than the remarks of Coulomb and Van Marum on the Euphorbia, whose milky juices flow so copiously from a wound, in consequence of the evident irritability of their vessels; but when the life of the plant is destroyed by electricity, all the flowing is at an end. It is superfluous to add any thing on this subject, and I return to that of the impregnation of flowers.
I have already mentioned that any moisture causes the pollen to explode, conse-
