PROCEEDINGS OF THE BRITISH ASSOCIATION. 441 



ttention of the Academie des Sciences, and this was supposed to arise from a 

 parasitic plant upon the animaL He thought the present plant was a species of 

 the genus Botrytis* 



Mr. Mallett read a paper on " The power possessed by Aged Trees to repro- 

 duce themselves from the centre of the Trunk." 



He observed that trees, at a certain period of their growth, became decayed 

 and hollow in the centre. This process was frequently followed by the splitting 

 up of the trees, so as to make it resemble several trees, instead of one. He then 

 described this process as arising from the power the bark possessed of depositing 

 new wood, when the old became decayed. The new wood thus deposited, be- 

 coming covered also with fresh deposited bark, was the cause of the entire 

 removal of some parts of the old bark, and the formation of the separate trunks 

 alluded to. But the process did not stop here, as the deposition of wood kept on, 

 and frequently filled up the interior of the tree, that had been formerly decayed. 

 The centre of the tree appearing to be filled up with " liquid wood." In proof 

 of his views, the author exhibited several drawings of old trees, as the Mulberry 

 at Battersea, the Cobham Chesnut, the Fortingal Yew, &c. — Mr. Mallett also 

 exhibited some very fine specimens of crystallized Haematine, the colouring 

 principle of the Logwood tree ( Hcematoxylon Campeachianum.) 



Professor Henslow differed from Mr. Mallett ; he had seen tree grow within 

 tree, and was more inclined to attribute it to the accidental deposition of a seed 

 within the old tree, than to any deposition of new wood. According to Mr. 

 Mallett, the growth of trees might be eternal, but this was an unphilosophical 

 assumption. — Mr. Duncan stated, in confirmation of Professor Henslow's views, 

 that he had seen a Sycamore growing within a Lime. 



Professor Graham stated that he had lately seen an instance in which the 

 branch of one Fir tree had been transferred to another, by the union of the wood 

 of the two branches, which had been accidentally brought together, and subse- 

 quently separated. He had seen also a Beech and Horse Chesnut united, and 

 another instance of union between the Ash, Elm, and Holly. He thought it 

 impossible that the fluids of the different trees in these cases should be trans- 

 mitted generally through the united trunks. There must be, however, organic 

 connexion between these trees, and he was puzzled to know the kind of union 

 that existed. — Professor Henslow doubted whether organic connexion existed in 

 the cases related ; a very close approximation might take place, but he questioned 

 the possibility of an organized interval. 



* The dead flies in the town of Liverpool assumed generally the appearance adverted to by the 

 President, and an eminent comparative anatomist, to whom we mentioned it afterwards, stared 

 his belief that it was some excrescence [arising from disease in the fly. He remarked that it 

 always occurred in the same spot and on both sides of the fly. 



