ENDS AND CONNECTIONS OF THE BUNDLES. 377 



The glandular spots on the under side of the leaf of Prunus Laurocerasus also lie over 

 a knot or a narrow mesh of the net of bundles, and from this some vessels or tracheides, 

 which are not numerous, branch off into the epithema lying below the glandular 

 epidermis. 



In the petiole of Passijlora cmrulea and its allies a bundle ending below the epithema 

 enters the cylindrical appendages or teeth, which end with a concave glandular surface. 

 The conditions are similar in the appendages of the petiole of AmygdalecE. Several 

 bundles running to the glandular terminal surface enter the broad round appendages of 

 the petiole in Stlgmaphyllum. 



In the Acacias the glandular spots of the appendages of the petiole behave very dif- 

 ferently according to the species (cf. p. 98), A number of small bundles, here and there 

 reticulately connected, enter the elongated, wart-shaped projection of the base of the 

 petiole of A. lophantha, running towards the free surface, and here ending in the epi- 

 thema. Below the flat wart-like prominence on the upper edge of the base of the 

 phyllodes of A. marginata, and A. calamifolia, numerous isolated short tracheae branch 

 off from the neighbouring strands of the net of bundles, and without being united into 

 distinct bundles turn towards the epithema and there end. The same is to be seen here 

 and there at the base of glandular pocket-like depressions of A. latifolia and its allies, 

 but the vascular ramifications are here sparse and very short, while, on the other hand, 

 the thick xylem groups of the bundle-net often border directly on the epithema. 



As regards the characteristics of the group of epithema, in many cases it 

 scarcely deserves a special name, as it is nothing but a small-celled parenchyma, 

 which, on the one hand, passes over immediately into the other larger-celled 

 parenchyma of the organ, and, on the other hand, into the interstitial cells of the 

 end of the bundle. So, for example, in the glandular appendages of the petiole of the 

 Passiflor^e, and in most ends and teeth of leaves. Here the epithema is distinguished 

 from the lacunar chlorophyll-parenchyma by the smaller size of its cells, and by 

 their containing little or no chlorophyll, the places occupied by the epithema thus differ- 

 ing in their pale colour from the green surface of the leaf. The epithema passes over 

 quite gradually on all sides into the large-celled chlorophyll-parenchyma ; the water- 

 pores of the epidermis lead immediately into the intercellular passages of the latter. 

 In the leaf-teeth of Papaver orientale even all transitional forms are present between 

 the small parenchymatous cells of the epithema and the tracheides of the bundle-ends. 

 These epithemata have a very different form and extent, according to the shape and 

 size of the bundle-ends and teeth of the leaf; in the narrow ends and teeth of the leaves 

 of Fuchsia, Callitriche\ and Primula sinensis, for example, they are quite small bodies, 

 showing only a few cells in section, and lying immediately below the large stomatal 

 cavity, which belongs to the water-pore, situated at the end. In the broad teeth of 

 the leaf of Papaver and Brassica, and in the crenations of Tropseolum, the group of 

 epithema, which receives several ends of bundles, is a many-layered small-celled 

 parenchymatous mass, approaching i^^"!^ in breadth. 



On the other hand, however, many ends of bundles mn out into epithemata, which 

 are sharply distinguished and limited. The furrows of the leaves of species of Ficus, 

 Crassula, and Saxifraga, the glandular petiolar appendages of the Acacias, and many 

 other cases, are examples of this. At the parts of the leaves indicated at p. 51, of 

 species of Crassula, and of Rochea coccinea (Figs. 180-182), a thick bundle runs 



* Borodin, I.e.; compare p. 51. 



