Onap. XV. STRUCTURE OF LEAVES. 333 
are linear, much attenuated towards their tips, and 
several inches in length. The upper surface is con- 
cave, the lower convex, with a narrow channel down 
the middle. .Both surfaces, with the exception of the 
channel, are covered with glands, supported on pedicels 
and arranged in irregular longitudinal rows. These 
organs I shall call tentacles, from their close resem- 
blance to those of Drosera, though they have no power 
of movement. Those on the same leaf differ much in 
length. The glands also differ in size, and are of a 
bright pink or of a purple colour; their upper sur- 
faces are convex, and the lower flat or even concave, 
so that they resemble miniature mushrooms in appear- 
ance. They are formed of two (as I believe) layers 
of delicate angular cells, enclosing eight or ten larger 
cells with thicker, zigzag walls. Within these larger 
cells there are others marked by spiral lines, and 
apparently connected with the spiral 
vessels which run up the green multi- 
cellular pedicels. The glands secrete 
large drops of viscid secretion. Other 
glands, having the same general 
appearance, are found on the flower- 
peduncles and calyx. 
Besides the glands which are borne 
on longer or shorter pedicels, there 
are numerous ones, both on the upper 
and lower surfaces of the leaves, so 
small.as to be scarcely visible to the Fie. 4. 
naked eye. They are colourless and § O”*pyruum us! 
almost sessile, either circular or oval Rist. of Test aaa 
in outline ; the latter occurring chiefly _ing lower surface. 
on the backs of the leaves (fig. 14). 
Internally they have exactly the same structure as 
the larger glands which are supported on pedicels ; 
