176 On the Relationship existing [no. 4, new series, 
many only open their leaves or flowers to the sunshine, while others 
the plantcs iristes, the watchmen of the flower garden, only spread 
abroad their beauties to the night. Other plants exhibit a certain 
amount of irritability, or sensitive qualities, under mechanical or 
chemical stimuli. The Drosera and Dioncea woo the unwary fly 
to its destruction shutting it up in deadly folds, while the Mimosa 
sensi'.iva and a few others will shriek from the most delicate 
touch, and may be laid asleep, during any severe operation of the 
gardener, under the influence of oplam or Chloroform. If on 
the other hand we assume as the characteristic of the animal, its 
capability of changing its position, we still find similar properties 
in the plant ; for vegetable organisms are ia some instances capa- 
ble of changing their position and performing other movements. 
Thus the Zooipores of Cryptogamic plants are locomotive, and the 
Desmodium gyrans is possessed with a restless activity, its lateral 
leaflets dancing a perpetual measure to the music of the air. As 
we compare then these indications of sensibility, and these locomo- 
tive powers in the vegetable with the humbler endowments of such 
an animal as the sponge, which remains through life chained to one 
little spot of rock, giving out no indications of sensibility, we must 
at once be struck with the difficulties attending a true distinction, 
and the intimate relation that exists between the two kingdoms in 
question. True, we cannot instance the automatic performances of 
the vegetable as identical with the similar endowments of animal 
life, but still they indicate a sympathy, a harmony existing between 
the two organizations, and show us how closely the great principles 
of animal and vegetable life converge. Indeed, as they approach 
the common centre, the little cell that is the habitation of both, it 
is perhaps impossible to say, here begins animal a7id there vegetable 
These, here in their infancy, are subtle essences far beyond 
our conception, and the naturalist, as he gathers this new world to- 
gether on the field of his microscope, can only Judge and ?ia?ne, after 
long and patient study of conformation and habits. 
Thus far we have dealt in generalities, let us now therefore exa- 
* This animal and vegetable aflanitj is very amusingly discussed at p. 448 of 
th« April Noj of th« Dubliu Umyersitj Magazine l§o7.— 
