5. In the Helleborus-niger, Christmas-rose, after the seeds are grown to a certain size, the nectaries and stamens drop off, and the beautiful large white petals change their colour to a deep green, and gradually thus become a calyx inclosing and defending the ripening seeds, hence it would seem that the white vessels of the corol served the office of exposing the blood to the action of the air, for the purposes of separating or producing the honey, wax, and prolific dust, and when these were no longer wanted, that these vessels coalesced like the placental vessels of animals after their birth, and thus ceased to perform that office and lost at the same time their white colour. Why should they loose their white colour, unless they at the same time lost some other property besides that of defending the seed-vessel, which they still continue to defend? 6. From these observations I am led to doubt whether green leaves be absolutely necessary to the progress of the fruit-bud after the last year's leaves are fallen off. The green leaves serve as lungs to the shoots and foster the new buds in their bosoms, whether these buds be leaf-buds or fruit-buds; but in the early spring the fruit-buds expand their corols, which are their lungs, and seem no longer to require green leaves; hence the vine bears fruit at one joint without leaves, and puts out a leaf-bud at another joint without fruit. And I suppose the green leaves which rise out of the earth in the spring from the Colchicum are for the purpose of producing the new bulb, and its placenta, and not for the giving maturity to the seed. When currant or goosberry trees lose their leaves by the depredation of insects the fruit continues to be formed, though less sweet and less in size. 7. From these facts it appears that the flower-bud after the corol falls off, (which is its lungs,) and the stamens and nectary along with it, becomes simply an uterus for the purpose of supplying the growing embryon with nourishment, together with a system of absorbent vessels which bring the juices of the earth to the footstalk of the fruit, and which there changes into an artery for the purpose of distributing the sap for the secretion of the saccharine or farinaceous or acescent materials for the use of the embryon. At the same time as all the vessels of the different buds of trees inosculate or communicate with each other, the fruit becomes sweeter and larger when the green leaves continue on the tree, but the mature flowers themselves, (the succeeding fruit not considered) perhaps suffer little injury from the green leaves being taken off, as some florists have observed. 8. That the vessels of different vegetable buds inosculate in various parts of their circulation is rendered probable by the increased growth of one bud, when others in its vicinity are cut away; as it thus seems to receive the nourishment which was before divided amongst many. NOTE XXXVIII.--VEGETABLE IMPREGNATION.