A BOTANICAL EXCURSION IN MY OFFICE. 929 
motion. The plant has given birth to an offspring pos- 
sessing apparently the peculiarly animal power of spon- 
taneous motion. Let us now place a little solution of 
iodine or laudanum so that it will come in contact with 
our little moving body, and in a moment motion ceases, 
—we have killed it! 
Let us now carefully arrange our light, illuminating the 
stage a little obliquely, put on our 4 objective, adjust it 
‘for the glass cover, and see if we cannot discover the 
cause of the motion. Do you not see a circle or crown 
of long, lax, streak-like particles attached around the 
bright transparent space before spoken off. These are 
cilia, fine threads of condensed protoplasm. If during 
life one of these motive bodies is placed in a liquid con- 
taining very fine particles, as a dilute solution of India- 
ink or gamboge, and watched, constant currents will be 
seen to be produced by these cilia, which are in such 
rapid motion that they cannot be otherwise detected. 
It is, then, by virtue of the constant lashing of the cilia, 
that the little body moves, just as a boat moves by means 
of the scull. The movement of the cilia themselves is 
not a voluntary one; it is a form of the protoplasmic 
movements, of which cyclosis is one type. 
Let us take our motive body, killed by means of. the 
iodine, and add sulphuric acid to it; if cellulose be pres- 
ent, a bluish or purplish color will be produced. But 
there is none. In other words, our little body is composed 
simply of protoplasm and chlorophyl ; it is a cell without 
a wall. To these moving bodies the name of zoöspore is 
given. If you watch a living zoospore, in a little while 
its motion ceases, its cilia drop off, and it surrounds 
itself with a cellulose wall. i 
In most plants allied to the species under consideration, 
