THE LEAP. 



193 



" Another form which the axillary shoot assumes is 

 that of a pair of transversely-placed fleshy leaves, 

 each about half the size of the single recurved leaf 

 above-mentioned, or smaller (fig. 52 c and d), enclosing 

 between them one or two extra smaller pairs of fleshy 

 foliar organs. All these leaves, from those of the first 

 pair upwards, may be, owing to the very contracted 

 space in which they arise, considerably displaced from 

 the normal position, and here and there irregular 

 fusions may occur, as also correlative modifications in 

 development. 



" In several cases the spur-shoots begin with the 

 same transversely-placed pair of fleshy leaves, as in 

 the cases of the axillary shoots just cited, being imme- 

 diately followed by the usual scale-leaves of the spur- 

 shoot. 



" Reverting now to the afore-mentioned recurved 

 fleshy leaves which occur singly (or with extra leaves 

 of the axillary shoot on their adaxial side), in greatest 

 number in the upper part of the shoot, it was deter- 

 mined that this recurved leaf is formed through the 

 fusion, by their adaxial margins, of the two trans- 

 versely-placed leaves which occur in so many of the 

 axillary shoots, with which is incorporated, at least in 

 the basal region, one or two of the succeeding pair of 

 leaves which may or may not undergo (this could 

 scarcely be determined) some revolution in orientation. 

 This mode of origin of the outward-arching scale 

 could only be accurately determined by its anatomical 

 investigation,* for although the slightly bilobecl char- 

 acter of many of these scales seems to imply their 

 compound nature, the exact mode of union of the 

 component leaves could only be demonstrated when 

 it was seen that the vascular bundles, forming a row 

 of strands across the leaf, were orientated in such a 

 way that their xylem was directed outwards {down- 

 wards). In the basal region of the leaf, besides this 



* One of the interesting cases in which the origin and nature of an organ 

 can only be finally settled by the anatomical method of investigation. 



VOL. I. 13 



