‘DESCRIPTION OF PLATES. 147 
are really animal organisms. But when we see 
these little green spheres stretch themselves out 
and crawl about like so many microscopic snails, 
or, when there is sufficient water for navigation, 
swim freely about by means of their slender, whip- 
like flagellum, we can scarcely fail to agree with 
Kent in assigning them to the animal kingdom. 
The red pigment spot — so-called eye-speck — 
is situated near the anterior extremity of the body. 
Its function has not been determined, but it is not 
improbable that it is a rudimentary sense-organ. 
Euglena, like Amceba and the unicellular Alga, 
may assume an “ encysted ”’ condition, and remain 
quiescent for an indefinite period. This provision 
of nature for the preservation of these minute be- 
ings enables them to survive during the cold of 
winter and periods of drouth, and to resist desicca- 
tion to such an extent that they may be wafted 
through the air in dust from the bottom of a dried- 
up pond or gutter; and if they are fortunate 
enough to fall into an open cistern or any other 
body of water, they quickly resume their active 
state. 
Euglena multiplies by jisscon in a longitudinal 
direction. This mode of reproduction is common 
among the Infusoria; and some much higher in 
the scale, and unmistakably animal organisms, ex- 
hibit this curious phenomenon. The writer had, 
two years ago, the opportunity of observing the 
whole process in a very curious creature belong- 
ing to the genus Amphileptus. This is a ciliated 
infusorium having an oval body and a long neck. 
