270 DROSOPHYLLUM LUSITANICUM.  [Cuap. XV. 
The glands also differ in size, and are of a bright pink or of 
a purple colour; their upper surfaces are convex, and the 
lower flat or even concave, so that they resemble miniature 
mushrooms in appearance. 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 multicellular pedicels. The glands secrete large 
drops of viscid secretion. Other glands, having the same 
ais 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 
naked eye. They are colourless and almost 
sessile, either circular or oval in outline; 
the latter occurring chiefly on the backs of 
the leaves (fig. 14). Internally they have 
exactly the same structure as the larger 
glands which are supported on pedicels; 
and indeed the two sets almost graduate 
into one another. But the sessile glands 
differ in one important respect, for they 
never secrete spontaneously, as far as I 
Fic. 14. have seen, though I have examined them 
CProsephytium, ts under a high power on a hot day, whilst 
Part of leaf, enlargea the glands on pedicels were secreting co- 
seven times, show- piously. Nevertheless, if little bits of damp 
ing lower surface. Jbumen or fibrin are placed on these 
sessile glands, they begin after a time to 
secrete, in the same manner as do the glands of Dionwza 
when similarly treated. When they were merely rubbed 
with a bit of raw meat, I believe that they likewise secreted. 
Both the sessile glands and the taller ones on pedicels have 
the power of rapidly absorbing nitrogenous matter. 
The secretion from the taller glands differs in a remarkable 
manner from that of Drosera, in being acid before the glands 
have been in any way excited; and judging from the changed 
colour of litmus paper, more strongly acid than that of 
Drosera. This fact was observed repeatedly; on one 
occasion I chose a young leaf, which was not secreting freely, 
