president's address. 21 



the parent-tuber appeared to have been arrested. Several of the 

 numerous fibrous-like shoots originating from these points are 

 presumed to have pierced the rind of the tuber, or to have 

 developed immediately underneath the rind, and there to have 

 thickened into potat.-ies of the usual appearance. Another re- 

 markable fa<^t was, that, excepting through tlie slender shoots, or 

 stems, developing into tlie daught(^r-tubers, no direct communi- 

 cation seems to have established itself between these and the 

 parent, although, in sojne cases, the f )rmer were almost com- 

 pletely embedded in tlie cellular tissue of the latter. 



A section was exhibited under the microscope, showing the 

 altered condition of the cellular layer of the parent potato, where 

 it was immediately in contact with one of the enclosed tubers. 

 A sketch an<l diagrams illustrati]\g this unusual departure from 

 the ordinary development of tubers was also exhibited. 



Mr. Oliver also exhibited, under the microscope, the siliceous 

 valves of certain disciform Diatoraacece, remarkaT)ly abundant in 

 a deposit ol)tained from the water-supply of the town. These were 

 referred by him, with but little doubt, to the genus Cyclotella, 

 probably to C. operculata ; the difficulty of tlieir determination, 

 in part owing to the circumstances necessarilj'- attending their 

 collection after a passage through the apparatus and pipes of the 

 Water Company, rested on the possibility of their being the 

 isolated frustules of Melosira or other filamentous Diatom, or 

 such, rendered by special conditions abnormally free. 



Diatomacece from other places in the neighbourhood were also 

 upon the table. 



Living specimens of Anacharis alsinastrum (Bab.), were ex- 

 hibited, its character and habit cursorily described, and a brief 

 account given of its first appearance and rapid increase in various 

 localities. 



Examples of Sporiferous Coal from Fordel, in Fifeshire, the 

 subject of an interesting paper, by Dr. Balfour, in the "Trans. 

 Ed. Royal Society," were also on the table. 



The following Members were present : — Revs. G. C. Abbes, and 

 T. Green j Messrs Joseph Blacklock, Thomas John Bold, Jas. B. 

 Browning, Gainsford Bruce, George Bulman, John Fenwick (in 



