YOLVOX GLOBATOR. 



275 



A fresh-water alga of singular beauty and interest to 

 the microscopist is the Volvox globator. This little cell 

 so well known to the older observers as the globe- 

 animalcule, or revolving-cell, is represented in tig. 145, 

 Nos. 1, 2, 3, and Plate I. No. 15. These revolving globular 

 bodies were for a very long time classed with the lower 

 forms of animal life, and there remained for the micro- 

 chemical investigator of the present time to settle the per- 

 plexing question, and assign to them a place among plants. 

 .Leeuwenhoek first perceived the motion of what he 

 termed globes, "not more than the 30th of an inch in 



^ diameter, rolling through 

 water ; and judged them to 

 be animated." These globes 

 are studded with innumerable 

 minute green spots, each of 

 which is seen to be a perfect 

 cell, about the 3,500th part of 

 an inch in size, with a nucleus 

 and two active cilia attached. 

 The whole are bound together 

 by threads forming a beautiful 

 net-work. Within the globe 

 busy active nature is at work 

 carefully providing a continu- 

 ance of the species; and from 

 six to twenty little bright- 

 green spheres have been found 

 enclosed in the larger trans- 

 parent case. As each Kttle 

 cell arrives at maturity, the 

 parent cell enlarges, and 

 \. Voivox, just before the young burst ultimately bursts asunder, 



forth, showing the vesicle which en- launching forth its offspring 

 closes each. 2, Parent cell of Clos- 1 • i t / 



terium. 3, Douuiivm ciavatum. 4, to seek an independent exl - 



Staurastrum gracilis. tencQ Eoth o]der &nd 



younger spheres possess openings through which the water 

 freely flows, affording food and air to the wonderfully 

 constructed little being. 



Dr. Carpenter believes, "The Volvocinece, whose vegetable 

 nature has been made known to us by observation of cer- 



T 2 



Fig. 151. 



