312 PINGUICULA VULGARIS. [Cuar. XVI. 
Some thin slices of the common pea, which had been previously 
soaked for 1 hr. in water, were placed on a leaf, and quickly excited 
much acid secretion. After 24 hrs. these slices were compared under a 
high power with others left in water for the same time; the latter 
contained so many fine granules of legumin that the slide was rendered 
muddy; whereas the slices which had been subjected to the secretion 
were much cleaner and more transparent, the granules of legumin 
apparently having been dissolved. A cabbage seed which had lain for 
two days on a leaf and had excited much acid secretion, was cut into 
slices, and these were compared with those of a seed which had been 
left for the same time in water. Those subjected to the secretion were 
of a paler colour; their coats presenting the greatest differences, for 
they were of a pale dirty tint instead of chestnut-brown. The glands 
on which the cabbage seeds had rested, as well as those bathed by the 
surrounding secretion, differed greatly in appearance from the other 
glands on the same leaf, for they all contained brownish granular 
matter, proving that they had absorbed matter from the seeds. 
That the secretion acts on the seeds was also shown by some of 
them being killed, or by the seedlings being injured. Fourteen cabbage 
seeds were left for three days on leaves and excited 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 plants 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 Objects 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. 
