130 Professor Alexander Dickson on the 



by Mr Elwes. The cotyledonary tube here is of consider- 

 able length (about 3 inches), and in most cases it would 

 appear that the plumule remains over winter in a com- 

 paratively undeveloped condition, in this respect resembling 

 Leontice, as described hy Bernhardi, where only the coty- 

 ledons and a small tuber appear the first season, the 

 development of the plumule occurring in the second. In 

 the one I have figured, however, the plumule had developed 

 sufficiently to break through the base of the cotyledonary 

 tube, just as in Delpliiniurn or any of the other cases 

 mentioned. The cotyledonary laminae are expanded and 

 leaf-like; and in several specimens I observed the remarkable 

 peculiarity of the development of an adventitious root from 

 the cotyledonary tube a little above its base. 



EXPLA>'ATI0X OF PlaTE IX. FiG. A. 



Fig. A. — Outline sketch of seedling of Podophyllum Emodi. 

 Ic = Blades of the cotyledons. 

 tc = Cotyledonary tube ; formed by connation of the stalks of 



the cotyledons. 

 / = First leaf of plumule, which has broken out through the 



base of the cotyledonary tube. 

 ar = Adventitious root, springing from the lower part of the 

 cotyledonary tube. 



On the Occurrence of Foliage-leaves in Ruscus (Semele) 

 androgynus ; icith some Structural and Morphological 

 Ohservations. By Professor Alexander Dickson, 

 M.D. (Plates IX., X., and XL) 



(Read 12th July 1883.) 



For many years I have had, in my greenhouse at 

 Hartree, a plant of Buscus androgynus, grown in a large 

 flower-pot. The plant has thriven fairly well ; but the 

 aerial stems are less strongly developed than when tlie 

 plant is not so confined, — nor has it as yet flow'ered. 

 Lately, however, my attention was attracted by certain 

 leaves, with long petioles and ovate or lanceolate-ovate 

 blades, springing from the soil on the side of the plant 

 next the light. At first I thouglit that these leaves must 

 belong to some plant accidentally introduced along with 

 the Ruscus ; but on closer examination, when having the 

 plant divided for the purpose of propagation, I found that 



