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On the Reproduction of Buds. By Thomas Andrew Knight, /Ivy. 

 F.R.S. In a Letter to the Right Hon. Sir Joseph Banks, K.B. 

 P.R.S. Read May 23, 1805. \Phil. Trans. 1805, p. 257.] 



Mr. Knight begins his paper by stating, that every tree, in the 

 usual course of its growth, generates the buds that expand in the 

 succeeding spring ; but if these buds are destroyed, during the winter 

 or early part of the spring, other buds are in many species gene- 

 rated ; which buds perform the office of those that previously existed, 

 except that they never afford blossoms or fruit. This reproduction 

 of buds has not escaped the notice of naturalists ; but it does not 

 appear that they have ascertained from which of the various sub- 

 stances of the tree the reproduced buds derived their origin. 



After noticing some erroneous opinions respecting the origin of 

 buds, Mr. Knight proceeds to relate some observations and experi- 

 ments made by him on this subject. If the fruit-stalks of the Sea 

 Cale (Crambe maritima) are cut off in the spring, the medullary sub- 

 stance decays, and a cup is formed, the sides of which consist of a 

 woody substance, perfectly similar to the alburnum of trees. From 

 the interior part of this substance, new buds are frequently gene- 

 rated in the ensuing spring : hence it is obvious, that the buds, in 

 this case, do not spring from the bark ; but it is not equally evident 

 that they do not spring from some remains of the medulla. 



In the autumn of 1802, Mr. Knight discovered that the potatoe 

 possessed a similar power of reproducing its buds; which buds 

 sprung from tubers generated on the surfaces made by the knife in 

 dividing the root. In a former paper he has given some reasons for 

 supposing that the internal substance of the potatoe is alburnous : 

 he now observes, that there is in the young tuber a transparent line 

 through the centre, which is probably its medulla ; and that the re- 

 produced buds did not spring from the central part, nor from the 

 surface in contact with the bark, but from what he has supposed to 

 be the alburnum of the root. 



The author now gives an account of the experiments made, in the 

 autumn of 1802, on young apple, pear, and plum trees, raised by 

 him from seed, and, at that time, about two inches above the ground. 

 These plants, after removing some of the soil, were cut off, about an 

 inch below where the seed-leaves formerly grew ; so that a portion 

 of the root, about an inch long, and without any bud upon it, re- 

 mained exposed. In the beginning of April, many small elevated 

 points were seen on the bark ; these appeared to proceed from the 

 alburnum, and, as the spring advanced, perforated the bark, and 

 produced shoots. 



As it might be supposed that in the preceding experiment!? the 

 buds may have originated from the medulla, Mr. Knight thought it 

 right to make some similar experiments on old trees ; and found the 

 buds were reproduced by such trees, exactly in the same manner as 

 by the annual roots. 



Mr. Knight, in a former paper, has remarked, that the central 



