Page:Transactions of the Linnean Society of London, Volume 6 (1802).djvu/97

Rh speedily such matters pass into the vinous state, it seems possible that both of these might contain alcohol. Yet, it is also possible that something common to this latter substance, with the saccharine matter it is producible from, may be the real exciting cause.

The existence of absorbent vessels in the pollen is proved by the change of form, increased transparency, and great distention produced by the water. It is remarkable, that complete saturation usually brings the grains near to a spherical shape, however remote from it their original one.

It seems necessary to suppose the parenchyma for the following reasons. Something is evidently given out to the spirit before the dispersion of the grain commences. In some cafes this is visible In minute particles moving about in the drop; in others it is discoverable by the tinge on the dried space, and by the striæ which appear when more spirit is added. Now, if the grains consisted merely of the vegetable fibre formed into vesicles or cells, their texture would no more be destroyed by spirit than by water, and the penetration of the water would produce the same motions as that of the spirit. But if we suppose that, in proportion as the spirit penetrates the several parts of these curious capsules, some transparent substance is forcibly expelled from them; the various motions into which they are thrown will be easily explained by the recoil of the grain in the opposite direction. It will hence appear why the pollen of 1. which seems to consist of many separate cells, is driven alternately in all directions by their successive discharge, and why that of 4. which is a long tube rolled up, and probably with but one orifice is thrown into a rotatory motion. The opacity of this species during the discharge may be attributed to the evacuation of this canal and the returning transparency to the entrance of the spirit into it from the absorbent vessels, or at the orifice. I do not remember to have