128 PHOTO-MICROGRAPHS. 
pendent amceba. This is a common mode of 
multiplication. Multiplication also occurs by 
regular binary division.’ 
The Amoebz are not at all times engaged in the 
active work of seeking and digesting food. They- 
often remain in a state of repose for a considera- 
ble period. This is especially the case during the 
winter months, when they are to be found in the 
superficial stratum of ooze in ponds and ditches, 
and attached to decayed leaves and the roots of 
aquatic plants. In assuming this encysted condi- 
tion, they first cease to feed, and get rid of all 
undigested remnants of food. They assume a 
spherical form, and the external portion of the 
body-mass becomes hardened, so as to form a 
structureless membranous envelope. When con- 
ditions are favorable for their renewed activity, 
the envelope is ruptured, and the semi-fluid, living 
jelly (protoplasm) flows forth to resume its active 
and vagabond life. 
Professor Leidy thinks it probable that the pro- 
toplasm may also be broken up into reproductive 
“germs or spores” during the encysted state ; 
and one observer, Professor A. M. Edwards, has 
observed the issue of “ swarm-spores,” which swim 
about for a time like Infusoria. 
Fig. 1 (Plate II.) is a portrait from life of an 
amoeba quietly engaged in the important occu- 
pation of digesting his dinner. This consists of 
minute unicellular plants (Protococcus). The gran- 
ular material seen is mainly the partially digested 
1 Carpenter. 
