218 
LECTURE XII. 
One of the most elegant species of Vorticella is 
the Vorticella Convallaria, a beautiful transparent 
animalcule, the body of which is formed like a bell- 
shaped flnwer, and is furnished with a very long 
tail or stem, by which it affixes itself to whatever 
substance it pleases. When a groupe of these 
animalcules is viewed by the Microscope, it ex- 
hibits the appearance of a set of animated flowers, 
alternately stretching out their stems at full length, 
and again suddenly contracting them in a spiral 
twist as represented in the figures we are now 
viewing. This species is very common, and is 
generally found attached to the stems and under 
surface of the leaves of the Common Lemna minor 
or Duckweed. 
But a still more elegant species is the Vorti- 
cella racemosa. It is found during the summer 
months in clear stagnant waters, attached to the 
stalks of the smaller water plants and other objects; 
to the naked eye the whole groupe, on account of 
the great number of individuals composing it, is 
distinctly visible, in the form of a small whitish 
spot, resembling a kind of slime or mouldiness, 
but when placed under the microscope in a drop 
of water on a glass, its extraordinary structure is 
