Vegetable Physiology for the Year 1886. 61 



a similar appearance to the cortex. The upper edge of the 

 wound exhibited towards the end of the summer a large swell- 

 ing, while that of the lower Q(\gQ. of the wound had consider- 

 ably diminished. In the next year the leaves developed 

 themselves earlier on this tree than on such as had not been 

 wounded. In the beginning the tree was still very strong, 

 but in the course of the summer it shrunk, the leaves remained 

 small, and the development of the shoots was very inconsider- 

 able. The exudations on the surface of the decorticated lig- 

 neous body became drier, and in the third year were quite 

 dry. In the beginning of the third year the tree once more 

 shot forth, but the leaves remained small, etc. In the begin- 

 ning of the fourth year the tree was dead. I have made the 

 same observation on the hardy stem of an alder tree, which 

 also died in the fourth year, but did not exhibit any exuda- 

 tions on the cleansed surface of the ligneous body, which 

 seems chiefly to take place when the decortication has been 

 performed very late, for instance in July*. 



Dutrochetf has published some new observations on the 

 growth of coniferous stems ; the notices, however, on this 

 subject which we have seen in the journal cited are too short 

 for us to be able to judge of it with any certainty. We hope 

 that Dutrochet will soon describe this interesting subject more 

 in detail. 



HenslowJ has described two cases in which the dead 

 ligneous bodies of dicotyledons have been gradually inclosed 

 by new annual rings, similar to those cases which have been 

 described by Du Petit- Thouars and Lindley. In one of the 

 cases described, namely, in the stem of a poplar, it was only 

 one half of the surface of the stem, which had probably died 

 from decortication, and the ligneous layers of the next annual 

 ring had gradually deposited themselves laterally over the 

 decorticated place, so that so soon as the fifth year the wound 

 was closed, and the new ligneous ring again surrounded 

 the whole stem. Cases of this sort are however extremely 

 frequent, especially in willows, when in trimming, some 

 branches are cut off, the ligneous body of which is then 

 covered with new ligneous layers by a side branch. 



Some new observations of Giron de Buzareingues § on the 



* A notice of Mr. Nevin's recent experiments on the same subject was 

 given in our last volume, p. 553. — Edit. 



f Accro'issement en diametre du Pin us picea. — VInstitut de 1836, p. 427. 



\ On the disunion of contiguous Layers in the Wood of Exogenous Trees. 

 Jardine's, Selby's, and Johnston's Magazine of Zoology and Botany. Lon- 

 don, 1 836, i. p. 32. 



§ Mem. sur V accroisscment en grosseur des Exogenes. — Cojnpt. Renducs, 

 1836. 



