On the Use of Atr-Vessels in Plants. 85 
of the root, which I subjected to the microscope in every possible 
way likely to elucidate the truth. They all presented specimens 
in which both buds and seeds were plainly to be discovered ; one 
ef these, an horizontal slice, I shall give a figure of. In the 
centre of the root, buds will be discovered, and the seeds are im- 
bedded in the alburnum vessel next the bark (fig. 3. C, buds,) 
and (fig. 3. D, seeds.) 1 then divided the stem, and taking a 
perpendicular piece down the middle, it presented me with the 
line of life (mounting as it always does in’ small plants) in the 
eentre, with the buds attached to it; (see fig.4.) To complete 
the picture, I continued to cut to the top of the plant, and dis- 
covered the buds in a more advanced state, where they are first 
collected, for the use of communicating to them the different in- 
gredients ; their seeds and pollen (fig. 5.) which they had not 
yet received, though so much formed in appearance; for both 
stamens and seed-vessel were empty. I never dissected a plant 
more fitted to show every truth I wished to prove: Ist, that 
water interferes less with the essential properties of a plant than 
could be conceived ; that air-vessels are merely supporters ; 2dly, 
that the seed, bud, and pollen, are formed in the root in water 
plants, and not in ‘the seed-vessel and stamen; 3dly, that there 
is no perspiration in water- any more than in land-plants, though 
the latter have few hairs ; 4thly, that there is an invisible skin, 
which covers almost all vegetation, impervious to water; and that 
the hairs receive their liquid from the atmosphere, and not from 
the vegetables to which the; y belong. As I enter into the mi- 
nutiz of the formation of plents! these facts become more evident, 
and not a single vegetable do I dissect without their appearing 
too positive to be doubted: there is a curious appearance around 
the flowers of the plants of which I have given a specimen, 
which I never saw before and cannot account for. (See fig. 3. 
and fig. 4. at K.) I can at this time procure only the Potamo- 
getons and the Ranunculus aquaticus, and the flower in them 
has but just begun to form. ‘That the spiral is discovered in all 
corollas, is a fact ; but to see it all round in this manner is novel, 
and may, I hope, be the means of procuring further information. 
Shall I be pardoned for concluding this letter with breathing 
a doubt respecting that account which Theophrastus gives, that 
the Nymphea Lotus sinks under water every night? The very 
great care Nature takes in all water plants, to defend them from 
the element till after impregnation, is such, that I cannot believe 
she would suddenly change her laws, merely to make one flower 
of a system act in exact contradiction to a known principle. 
All water plants rise above the stream to perform the impreg- 
en of the seed; and when the flower is under water, before 
F3 it 
