
AS APPLIED TO PHYSIOLOGY. 249 
Do all plants, parasitical on roots, adhere in this manner ? 
If so, there is a marked distinction between them and those 
adhering to stems. If so also the runners of Loranthus are 
stems, as is pointed out by their producing leaf-bearing 
branches. 
Parasitical on the Riskah of Affghanisthan. 
'The consideration of these parasites, which resemble in 
their mode of attachment those species of Loranthus which 
have many suckers, will instruct us negatively on several 
points of vegetable physiology. 
It is at once evident that the parasite is not nourished by 
the ascending juices, for its absorbing points reach only to the 
surface of the latest formed wood. It is also equally evident, 
that it can only be nourished by the descending juices during 
the first year; that is, if the original absorbing surface of the 
concave papillose face or disc of the sucker, always remains 
the chief passage of nourishment, since in such cases the des- 
cending juices can no longer be in contact with the concave 
and papillose face of the disc. But to remedy this, if a 
remedy be required, such other parts of the immersed sucker 
as may be in contact with the last formed wood, may be 
absorbing.* 
The idea that jifta plants may be nourished by 
the juices of other plants, without undergoing any process 
of digestion, is contrary to every analogy of the animal 
kingdom, and yet digestion is as universal in vegeta- 
bles as in animals. Their supposed deficiency in stomata 
may bave led to this opinion; and it is only one of many 
proofs of how easily an ingenious theory may be adapted to 
views founded on false observation, that it has since been 
found that many, perhaps all, of the plants, to which stomata 
were denied, do possess them in one form or another. 
The proof, supposed to have been derived from certain 
parasitical parts allowing the passage of a solution of prus- 
* The reasoning o this Para. is grounded on the supposition of the truth 
of the prevailing cul of vegetable liba "9 
K 
