THE BIRTH OF 



tions, and by their incessant, alternate bending and 

 straightening propel the globule forward. This 

 motion continues for about two hours, when the 

 periods for resting become more frequent and 

 longer. The cellule, finding a suitable place, now 

 finally comes to rest, preferably on the shady side of 

 some fixed or large floating body ; the cilia disappear 

 or are withdrawn. The globule, until now a mass 

 of naked plasmodium, hardens or thickens exteriorly, 

 so as to form an envelope a firm, transparent, color- 

 less skin the globule becoming uniformly green. 

 After twenty -six hours a number of short, branching 

 tubes arise from the cell thus formed. These tubes 

 increase in size and length as the parent cell did, 

 until in fourteen days their ends burst, and give birth 

 to new cellules, that run again the life course thus 

 described. 



Other Algae, whether multiplying sexually or asex- 

 ually, produce similar plasmodic globules, which, 

 either before or after their separation from the parent, 

 burst and set free a swarm of minute ciliated 

 protoplasma that move their pear-shaped bodies by 

 means of their thread or whip-like cilia, two or more 

 in number, in the manner above described. These 

 swim alone, at times avoiding one another, or, if they 

 come in contact by their forward ends, remain an 

 instant so, then back away from each other and con- 



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