SECT. IV. DECOMPOSITE ORGANS,* 15Q 



But the Fir-tree will send out no bud at all if cut 

 down near to the root. It may be said that this is 

 merely the exception to the rule ; but we cannot, 

 after all, place much reliance on the doctrine of pre- 

 organized germes. 



Mr. Knight relates an experiment from which he According 

 thinks it follows that the buds are formed from the Knight. 

 descending proper juice. He intersected the run- 

 ners connecting the tubers of a potatoe witb the 

 stem, and immersed both portions in a decoction of 

 logwood. The decoction passed along in both di- 

 rections, but did not enter the stem, because in that 

 direction the communication is kept up only by 

 the bark through which the proper juice descends 

 from the leaves, and which admits not coloured in- 

 fusions : but in the opposite direction it was found 

 that the infusion had passed through an elaborate 

 assemblage of vessels between the bark and albur- 

 num, the ramifications of which were seen to ap* 

 proach the skin at the base of the buds, to which 

 they were thought to convey nourishment.* But 

 allowing the experiment to be correct, it does not 

 prove that buds are formed from the proper juice but 

 only nourished by it; as the experiment must have 

 given precisely the same result if the buds had pro- 

 ceeded from the pre-organized germes of Du Hameh 



But whatever may be the actual origin of the bud, 

 it is evident that its developement does not take 

 place except through the medium of the proper 



* Phil. Trans. 1SC3. 

 S 2 



