ON GROWTH AND EXTENSION IN THE VEGETABLE KINGDOM, 43 



by the state of the stock. I have long- since expressed the general 

 law of nature relating to this subject in the following terms : 

 the bud propagates the individual, the seed (produced by fructi- 

 fication) propagates tlie species, A graft of the Borsdorfer apple 

 reproduces Borsdorfer apples ; a seed of a Borsdorfer apple will 

 reproduce apple-trees, but these will not generally bear Bors- 

 dorfer apples. 



The generally received rule, that in grafting, the young wood 

 of the graft must be brought into connection with the young 

 wood of the stock is quite right. By young wood is meant the 

 outer layers of wood towards the bark, and it depends on the 

 species of tree how deep the wood may be still called young. I 

 had already made some experiments of this kind, and they have 

 been continued latterly in the Royal Botanic Garden of Berlin, 

 where they have been conducted by the accurate hand of the 

 inspector, M. Bouche. The bark never grew on to the bark, 

 nor did young wood ever grow if brought into connection with 

 bark only. So it is with budding. There must be wood in the 

 middle of the bud or eye, otherwise the bud will not grow, and 

 this wood must always be young wood, and must be fixed on the 

 outer layer of wood immediately under the bark, for the operation 

 to succeed. It was now necessary to examine young grafts 

 which had but just taken and begun to grow, and I selected for 

 that purpose one of the above-mentioned experiments, where 

 Robiiiia pseudacacia had been grafted on a stock of the same 

 species. The following was the result. The graft had been 

 inserted between tiie wood and the bark by crown-grafting ; it 

 had two buds, of which the upper one was earlier developed than 

 the lower, as is usually the case. In this state a longitudinal 

 section was made through the lower part of the scion. The 

 connection proved to be entirely with cellular tissue, without 

 any trace of vessels, although the layer of tissue is so thin as 

 to be scarcely perceptible to the naked eye. It always takes a 

 considerable time, in this instance two weeks, before the con- 

 nection is perfected, and the graft l)egins to shoot. In budded 

 roses I have observed the same connection, through parenchyma, 

 between the bit of bark attached to the bud, on which was also 

 necessarily a portion of wood, and the wood of the stock. When 

 the scion is a year old, the outer wood of the branch passes 

 into that of the scion without the slightest interruption, and 

 the cellular tissue which formed the first connection can no 

 longer be recognised.* In a three-year old scion of a tongue- 



* I should have said the cellular tissue had been resorbed, bad I seen any 

 grounds for employing this expression, almost always used without grounds. 

 If we were carefully to search, we should find the so-called resorbed matter 

 unresorbed. 



