40 M. Miiller on the Development of the Lycopodiacese. 



truncated by the cells of this part separating from one another, 

 so that it looks as if it had been torn (figs. 1, 3), and the organ 

 is then perfect. In this shape it continues until the end of the 

 annual growth of the plant, at the end of which period it withers 

 with the leaves, apparently without acquiring any further develop- 

 ment, since we never find anything in its interior difierent from 

 what has already been described. 



But the nature of its connexion with the longitudinal axis of 

 the branch is to be seen by making a delicate longitudinal sec- 

 tion. In this we observe that it is neither attached to the leaf 

 nor laterally upon the axis of the branch. It stands exactly be- 

 tween the two, and is united by several larger, transparent and 

 empty cells, usually two, with the green parenchyma which 

 passes off from the axis to the leaf. The organ never receives a 

 branch from the vascular bundle, although the vascular bundle, 

 which is given off from the axis to the leaf (figs. 5 c, 11 a), runs 

 close under it. If at a later period we cautiously detach a leaf 

 with the whole of its base from the stem, we always find upon it, 

 i. e. upon its thickened base, this organ removed with it, and it 

 would thence appear as if it really belonged to the leaf and had 

 been formed from the parenchyma of the same ; but the history 

 of its development speaks most decidedly against this last view. 



It is difiicult, with respect to this enigmatical structure, to at- 

 tain a view which shall give us even an approximation to its real 

 import. Even the history of development here leaves us at fault, 

 and a true solution of this question will probably only be found 

 when we know how widely this structure is extended throughout 

 the Lycopodiacese, in how many different forms it appears, and 

 when perhaps anomalies in its mode of formation shall be met 

 with. Meanwhile its analogues appear to me to occur in those 

 buds which are often met with in the axils, between leaf and 

 stem, in various other Cryptogamic plants, as in the axils of the 

 leaves of Br yum annotinum and others. Here however it must 

 not be forgotten that in our case the cells never acquire green 

 contents, while those often do. They consequently cannot be 

 regarded as buds. Are they little branches ? are they radicle 

 structures? Reasons on both sides may be brought forward, 

 which to me are yet inadequate to solve the question. I com- 

 mend it therefore to the attention of more skilful investigators. 



[To be continued.] 



