YOLVOX GLOBATOR. 



275 



A fresh- water alga of singular beauty and interest to 

 fclie microscopist is the Volvox globator. This little cell 

 BO well known to the older observers as the globe- 

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

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

 bodies can be kept a long time alive if exposed in a 

 .glass bottle to a rain-drip from a roof. In this way 

 they maintain their activity and produce antheridia, 

 which are distinguishable by their orange colour. 



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.nuclens 

 and two flagella attached. 

 The whoje 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 little 

 cell arrives at maturity, the 

 parent cell enlarges, and 

 , just before'the young burst ultimately bursts asunder, 

 atMRSSBWfi: "^S *& its offspring 

 tertum. 3, Doddium ciavatum. 4, to seek an independent exis- 



Staurastrum gracilis. 



Fig. 151. 



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- 



