1892.] The Tendrils of Passiflora caerulea. 206 
to the pith, and parenchyma in the xylem, which has three 
or four spiral vessels besides an annular vessel in each bundle. 
The central pith is generally found torn apart forming the 
lysigenetic intercellular spaces of De Bary.* 
The structure of the tip, however, is widely different from 
that of either of the regions just described. Near the ex- 
_tremity of the concave side may be seen the oval aperture of 
the cup formation lying transversely to the length of the ten- 
dril, appearing white because of the absence of chlorophyll in 
the tissues beneath. The cavity is .3~.4 mm. across in a i- 
rection parallel to the long axis of the tendril and about .8 
ity (fig. 6, @, a’). The collenchyma is composed of one row 
of shortened, strongly thickened cells terminating at the rim 
of the cup (fig. 6, 5, 6’). 
thin s they near the cup and are separated only by a 
is Sas of pith. The termination of the tracheary tissue 
cells «aes a mass of epithema,* composed of long, slender 
c a. oblique ends, appearing as a continuation the tra- 
Shoot ch touching directly the epidermal layer of the cup 
All the intervention of the collenchyma layer. _ : 
Di Jed tissues of the tendril are abundantly supplied with 
have foo cey-the parenchyma of the pith and cortex, which 
With th merous simple pits, oval in form, arranged transversely, 
Dicsnch: torus present. The inner side and radial walls of the 
Nicat yma of both the concave and convex surfaces commu- 
eee the adjacent cells by similar structures; those of 
Op BURT pe ERIS OF 
14 Com: zi 
18 Dp — Anatomy of Phanerogams and Ferns, Eng. Ed., 
d., p. 200. 
376. Comp, Anat. of Phanerogams and Ferns, Eng. Ed., pages 375- 
