SPONTANEOUS MOVEMENTS IN PLANTS. 
833 
one extremity, with very fine cilia, varying from two to a 
large number. As soon as these minute bodies free them¬ 
selves from the cell in which they are enclosed, the cilia begin 
to vibrate with great rapidity, the vibration being accom¬ 
panied by a movement of rotation of the bodies themselves on 
their axis, occasioned apparently by rapid and spontaneous 
contractions; the result being a quick motion of the body 
through the water—undistinguishable, in fact, from that of 
some of the lower forms of animal life—continuing for a 
period varying from half an hour to several hours, at the 
expiration of which they settle down, reassume the characters 
of ordinary vegetable cells, lose their cilia, and give rise, by 
cell-division, to new individuals resembling the parent-plant. 
Those zoospores, which are furnished wfith cilia at one 
extremity only, direct that extremity, which is destitute of 
chlorophyll or green colouring matter, towards the light. 
Closely resembling these zoospores are the “ spermatozoa^ of 
the higher orders of cryptogamic plants, ferns, equisetums, 
and mosses. These bodies are produced in the antheridia or 
male organs, again by a modification of the protoplasmic 
cell-contents; they are filiform bodies of various forms, 
mostly presenting one or more spiral curves, and furnished 
with vibratile cilia. When released from the parent cells, 
they move about with great activity until they come into 
contact with the opening of the archegonium or female organ, 
which they enter, and thus fructify the germ of the new plant. 
Pringsheim describes the process by which the spermatozoa 
enter the archegonium as a very peculiar twisting motion, due 
to the action of the mucus or protoplasm of the germ-cell. 
He has seen a large number of spermatozoa enter a single cell, 
forming a kind of chain. 
In describing these curious bodies, of the connection of 
which with the vegetable kingdom there is no room for doubt, 
one is irresistibly reminded of those lowly forms of animal life 
* known as Amoeba and Gromia, consisting apparently of shape¬ 
less masses of protoplasm, possessing indeed far more re¬ 
stricted powers of locomotion than the zoospores and sper¬ 
matozoa, their faculties in this respect being confined to the 
protrusion and retractation of arms or pseudopodia, by means 
of which a slow movement is effected. If the possession of 
consciousness and of a voluntary control over the movements 
of the body belongs to the animal kingdom, even to its lowest 
forms, it is difficult to frame any cogent reason for denying 
these faculties to the vegetable organisms which we have been 
considering. A very interesting problem also presents itself 
for solution in the almost perfect identity of constitution 
