Qnar. XVI. SECRETION, ABSORPTION, DiGESTION. 387 
much secretion; they were then placed on damp sand under 
conditions known to be favourable for germination. Three 
never germinated, and this was a far larger proportion of deaths 
than occurred with seeds of the same lot, which had not been 
subjected to the secretion, but were otherwise treated in the 
same manner. Of the eleven seedlings raised, three had the 
edges of their cotyledons slightly browned, as if scorched; and 
the cotyledons of one grew into a curious indented shape. Two 
mustard seeds germinated; but their cotyledons were marked 
with brown patches and their radicles deformed. Of two radish 
seeds, neither germinated; whereas of many seeds of the same 
lot not subjected to the secretion, all, excepting one, germinated. 
Of the two Rumex seeds, one died and the other germinated ; 
but its radicle was brown and soon withered. Both seeds of the 
Avena germinated, one grew well, the other had its radicle brown 
and withered. Of six seeds of the Erica none germinated, and 
when cut open after having been left for five months on damp 
sand, one alone seemed alive. Twenty-two seeds of various 
kinds were found adhering to the leaves of piants growing in a 
state of nature; and of these, though kept for five months on 
damp sand, none germinated, some being then evidently dead. 
The Effects of Ohjects not containing Soluble Nitrogenous Matter. 
(16) It has already been shown that bits of glass, placed on 
leaves, excite little or no secretion. The small amount which 
lay beneath the fragments was tested and found not acid. A 
bit of wood excited no secretion; nor did the several kinds of 
seeds of which the coats are not permeable to the secretion, and 
which, therefore, acted like inorganic bodies. Cubes of fat, left 
for two days on a leaf, produced no effect. 
(17) A particle of white sugar, placed on a leaf, formed in 
1 hr. 10 m.a large drop of fluid, which in the course of 2 
additional hours ran down into the naturally inflected margin. 
This fluid was not in the least acid, and began to dry up, or 
more probably was absorbed, in 5 hrs. 30m. The experiment 
was repeated; particles being placed on a leaf, and others of 
the same size on a slip of glass in a moistened state; both being . 
covered by a bell-glass. This was done to see whether the 
increased amount of fluid on the leaves could be due to mere 
leliquescence; but this was proved not to be the case. The 
particle on the leaf caused so much secretion that in the course 
_of 4 hrs. it ran down across two-thirds of the leaf. After 8 hrs. 
the leaf, which was concave, was actually filled with very viscid 
