“ The only internal organs of the Rhizopoda are the ‘vacuoles,’ those which contain more or less digested food and those which contain the waste matter or excreta of the body. The latter are the larger and more conspicuous, and, owing to the sudden collapse when the excreta are thrown out of the body, are known as ‘contractile’ vacuoles. ”

“ Reproduction takes place by simple budding or fission, the two processes differing only in the relative size of the resulting individuals. The formation of spores, however, occurs in many cases, especially after a resting period. ”

“ In most cases during such a resting period the rhizopod surrounds itself with a firm, impervious coat, called a ‘cyst.’ When the unfavorable conditions cease the sarcode divides up into several minute spores, each of which on the dissolution of the cyst becomes a new individual. The growth of these individuals is rapid when food is abundant. ”