The Rev. P. Keith on the Origin of Buds. 431 



doctrine of the writer, who discards the hypothesis of Du Hamel 

 and of Knight, I cannot see how we are to do without it ; as he 

 seems to acknowledge no movement of any individual bud be- 

 yond that which must arise from the general expansion of the 

 whole shoot, excepting a horizontal movement. But if it has 

 been shown that buds do occasionally issue from points on the 

 surface of the stem, to which they could not possibly have come 

 by any horizontal channel, then we shall be compelled to ac- 

 count for their appearance in some other way. 



The second hypothesis is not without its difficulties, any more 

 than the first ; but it accounts much better for the anomaly in 

 question. The impenetrable veil which overhangs the subject 

 of generation, whether animal or vegetable, whether seminal or 

 by a bud, conceals for ever from the observation of man the 

 commencement of those recondite and mysterious processes by 

 which the operation is effected, and leaves us no resource be- 

 yond that of watching its future results, and forming our opi- 

 nions by inference. Hence the hypotheses of Du Hamel and 

 of Knight, by both of which we have the means of conveying 

 buds to every new layer of wood in all imaginable cases, not ex- 

 cepting even the case that I have now presented to the notice 

 of this Society ; and yet we need not confine ourselves to the 

 precise terms or principle of either the one or the other. Du 

 Hamel gives to the plant a profusion of what he calls pre-orga- 

 nized germs, but I do not recollect that he specifies their origin. 

 Mr. Knight gives to the proper juice an unlimited capacity of 

 forming and of dispersing buds, — which may be thought to be 

 rather too gratuitous, particularly as his experiments do not so 

 much prove that buds are formed by the proper juice, as that 

 they are nourished by it. But if it is admitted that one bud 

 has the capacity of generating others like itself, the difficulty is 

 surmounted. Say that this process is effected by the bud or 



VOL. XVI. 3 k buds 



