86 THE SCIENCE OF LIFE. 



eight, or sixteen new cells. The new cells are motile, hav- 

 ing each two long vibratile filaments or cilia. They may 



be seen swimming, 

 tumbling, or rotat- 

 ing in the water. 

 At times they are 

 surrounded by a 

 sac, which may be 

 at some distance 

 from the bioplasm. 

 The motile cells 

 may also multiply 



FIG. 25. Development of Protococcus : a. Still form. 

 b. Motile form. c. Self-division and zoospores. by Subdivision, and 



in some cases the minute primitive cells, when set free, 

 have very active movements, and rank as Zoospores, (liv- 

 ing spores,) or Micro-gonidia, (small angular particles, 

 from division of the bioplasm.) The varieties connected 

 with the history of this single plant have been sometimes 

 described as distinct species, and even genera of Animal- 

 cules, because of their shape and motions. 



4. The family of Palmellacece, to which the forms re- 

 ferred to belong, contain some kinds of singular interest. 

 The " Red Snow," which sometimes colors extensive 

 Alpine or Arctic tracts, is composed of myriads of Pro- 

 tococcus cells, in a quiescent state, with the chlorophyll 

 of a red color. The Palmella cruenta, or " Gory Dew," 

 appears sometimes as tough gelatinous masses of the 

 color of coagulated blood, and extends over a consider- 

 able area. In this way we may account for showers of 

 flesh, blood, etc., which are often regarded as bad omens 

 by the ignorant. 



