Ai'R. 1S95.] BOTANICAL SOCIETY OF EDINBURGH. 417 



and the groove very much smaller. At its lower end the 

 petiole is attached to the stem by a broadly sheathing 

 vagina, the upper margin of which is prolonged into two 

 long subulate somewhat spreading stipules, behind each of 

 which is found a short triangular tooth with a sharp 

 accuminate apex curved distinctly downwards, and some- 

 what resembling a minute recurved rose prickle. Other 

 tooth-like projections appear occasionally on the vaginal 

 margin, generally in descending series below this main one, 

 but, unlike it, they are not of constant occurrence. 



Of the three leaflets constituting the lamina, the 

 terminal one is slightly larger than the other two, but this 

 difference is not so well marked here as in the adult form, 

 the leaflet being but slightly broader than the other, and 

 not very much longer. The apical sinus, with its basal 

 point, is generally more highly developed in this second 

 than in the first leaf, and especially so in the terminal 

 leaflet, but even there not so highly as in the adult leaves. 

 In the same way the serration of the margin here is inter- 

 mediate between that seen in the first leaf and that 

 occurring in those formed later. The first three leaves 

 may, in fact, be considered as embryonic structures, 

 gradually increasing in complexity as they pass upward. 

 The fourth leaf, on the other hand, differs but slightly if 

 at all from that succeeding it, and must therefore be 

 looked upon as the first adult leaf borne by the plant. 



The earlier leaves show, as regards their position on the 

 axis, a gradual transition from the opposite arrangement, 

 exemplified in the cotyledons, to the ^ spiral ascending 

 from right to left, which is characteristic of the higher 

 parts of the primary axis. As the stem increases in 

 height the lower leaves fall off, leaving the vaginae each 

 with its pair of stipules still attached to the axis. 



Branchixg. — The cotyledons and all the succeeding 

 leaves on the primary axis bear in their axils branch buds, 

 and these with the exception of the cotyledonary buds 

 develop at once into branches during the first year. 

 These branches bear leaves similar in all respects to those 

 borne on the main stem, and arranged, like them, in a 3 

 spiral rising from right to left, and consequently homo- 

 dromous. 



TRAXS. BOT. SOC. EUIN. VOL. X.\. 2D 



