402 PHILOSOPHICAL TRANSACTION.V [aNNO 1773, 



every one of those, which were thus cut, succeeded, while several of the neigh- 

 bouring flowers miscarried. 



Thus did a snail teach him how to render a tree fruitful; nor is it the first 

 time that animals have been the instructors of mankind. However, this process 

 is not very practicable in a large orchard ; but it might be adopted in an espalier ; 

 in which one would choose to procure a great deal of fruit from trees of the best 

 sort. It may indeed be questioned, whether the suppression of the stamens 

 would not render the fruit barren; and in fact he found, that though the flowers 

 of the dwarf apple-tree, whose petals and stamens were eaten up by the snail, 

 gave apples equally large and beautiful, and that when he came to open them, 

 he found the capsules formed as usual at the centre of them ; yet they were en- 

 tirely empty, without the least appearance of a pip. Absolute fructification 

 therefore did not take place; since botanists, with reason, call nothing fruit but 

 the seed, which contains the germen, which is to perpetuate the species. All 

 the other parts, being only intended to co-operate in the formation and preser- 

 vation of the seeds, perish of course, when once the seeds are come to maturity 

 and perfection, and the work of nature fulfilled. Another remarkable thing in 

 these apples is, that in the upper part there was found a much deeper cavity than 

 usual. It was 8 or 9 lines deep. The orifice of this cavity was bordered by 5 

 tubercles, indented and somewhat elevated; but there was no vestige of the 

 calyx, which it is well known remains always to the upper part of apples and 

 pears, and is commonly called the eye. 



But to return to the first experiment; the consequences of which, as before 

 described, seem to prove, l . First that the circulation of the sap does not take 

 place in plants, as the circulation of the blood in animals. This may be deduced 

 from the following observations. The tree in the hot-house went through all 

 its changes during the winter, and the branch exposed to the open air underwent 

 none; consequently the sap, which was in action in the root, stock, and head, 

 of the tree, did not circulate through the branch without; which had no share 

 in the vegetation of the roots and trunk. It might indeed be argued, that the 

 cold air, to which this branch was exposed, stopped the circulation, and there- 

 fore that the first experiment would not be decisive: but the inverse of it seems 

 fully so. The tree placed on the outside of the hot-house continued, during the 

 whole winter, in the state of numbness, natural to all trees, which are exposed 

 at that season ; but one of its branches, which was in the hot-house, put forth 

 successively its buds, leaves, blossoms, and fruits. While therefore the root of 

 the tree, to which this branch belonged, was in the ground so frozen, that the 

 pot itself in which it stood was broken by it, while the stock and top of the tree 

 were so covered over with ice, that many of the branches were killed; this branch 



