349 



Cellular granulations at first appeared on the end which was now 

 uppermost and out of the ground, a circumstance which militates 

 against the inference drawn by some, namely, that the physical law 

 of gravitation operates in causing the sap to descend. 



In conducting this experiment, I have invariably found that no 

 cellular callus formed at the lower extremity, as would have been the 

 case had I planted the cutting in the regular way. The young roots 

 were protruded laterally from the bases of leaf-buds under ground ; 

 when one or more of these elongated, the axis made a sharp curve 

 upwards, until it regained its natural position. The growth and 

 woody formation went on then in the usual way. In some cases the 

 portion of the cutting above ground remained alive during a consider- 

 able period, though no leaf-buds grew on it. It, however, soon died 

 after the ascending shoot gained strength. 



This experiment, in my opinion, also tends to prove that no regular 

 return of assimilated bark-sap takes place in the formation of wood, 

 because, if such were the fact, the portion of the cutting above ground 

 would have lived and continued to receive the annual deposits, which 

 was not the case. 



The beautiful example I have laid before the Academy of the junc- 

 tion of stock and graft, proves, beyond any manner of doubt, that the 

 two increase by separate growths of their own wood, as thoroughly as 

 if they still grew on separate roots. I cannot, therefore, see how this 

 fact can be got over by those who hold that exogenous plants increase 

 by annual deposits of bark-sap. It will not, however, do to draw final 

 conclusions from isolated cases on a subject in which, if Dr. Schleiden's 

 reasoning be correct, so great a change must necessarily follow in our 

 views of this part of the science of vegetable physiology. 



David Moore. 



Glasnevin, Dublin, June, 1851. 



Pilularia glohulifera growing submerged at Henley Park, near 

 Guildford. By the Kev. W. W. Spicer, M.A. 



As Mr. Newman states in his ' History of British Ferns ' that he 

 knows no instance of Pilularia globulifera growing submerged, it may 

 be interesting to botanists to know that it does so in a large pond or 

 lake on the estate of H. Halsey, Esq., with whom I am now staying, 

 near Guildford, in Surrey. The pond covers eleven or twelve acres. 



