Mr. G. Dickie on the Gemma of Polygonum viviparum. 55 



IX. — Additional Observations on the Gemmce of Polygonum 

 viviparum. By George Dickie, Esq., A.L.S., Lecturer on 

 Botany in the University and King's College, Aberdeen. 



A description of the Gemmae of Polygonum viviparum 

 having been already given in the 32nd Number of the Annals, 

 the following account of their original development, and of 

 their manner of growth, will serve to complete the history of 

 these remarkable bodies. Having procured in the early part 

 of the season, from a locality in this neighbourhood, very 

 young flower stems, both flowers and gemmae were carefully 

 dissected ; the former (which invariably occupy the summit of 

 the flower stems) were much more advanced than the latter. 

 Fig. I. represents one of these magnified. Two nearly co- 

 nical processes are seen placed side by side ; on separating 

 these, two similar bodies are seen in the interior alternating 

 with the former ; by tearing asunder these last, two others are 

 seen similarly inclosed (figs. 2„ and 3.) ; the difference in length 



and breadth of the two innermost is now more conspicuous 

 than in the two outer. Each of these concentric bodies may 

 be considered, the one as a young leaf and the other a bud in 

 its axil. They are all of a very delicate texture and pale co- 

 lour ; at this period the mass of cellular tissue enclosing starch 

 grains is not developed, neither have the pink cells alluded to 

 in the former paper yet appeared. The bud at the apex of 

 each body is therefore first formed, and afterwards a quantity 

 of fecula is stored up at its base. 



A considerable number of perfectly formed gemmae, shortly 

 after being gathered from the mature flower stem, were planted 

 in a pot of mould, the apex of each alone protruding from the 

 soil; they were daily supplied with water. A few days after 

 being planted, a young leaf appeared at the summit of each, 

 the petioles made rapid progress, and some reached nearly 

 the length of an inch a week after the first appearance of the 



