VOLVOX GLOBxVTOR. 





A fresh-water alga of singular beauty and interest to 

 tiie microscopist is the Volvox glohator. This little cell 

 so well known to the older observers as the globe- 

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

 JSTos. 1, 2, 3, and Plate I. ^o. 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. 

 L.eeuwenhoek first perceived the motion of what he 

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



diameter, through water ; 

 and judged them to be ani- 

 mated." These globes are 

 studded with innumerable 

 minute green spots on the 

 surface, each of which is a cell 

 about the 3500th part of an 

 inch in size, with a vivid nu- 

 cleus having many ever-active 

 cilia, that bristle over their 

 spherical home and are bound 

 to each other by bands form- 

 ing a beautiful net - work. 

 Within this globe busy active 

 nature is at work carefully 

 providing a continuance of the 

 species ; andfrom six to twenty 

 little bright - green spheres 

 have been found enclosed in 

 the larger transparent case. 

 Pjg j5j^ As each one of these arrives 



Volvox, just before the youn? burst at maturity, the parent cell 

 forth showing the vesicle which en- enlarges: thcu bursts asunder 



closes each. 2, Parent cell of Clns- fT> ) 



terium. 3, Docidium davatum. 4, tO lauuch forth itS oftsj^riug 



Staurastrum gracilis. -^^^^ ^ ^^^^^^^^^ ^,^^.j^ g^,^^ 



the older and younger spheres possess openings through 

 which the water freely flows, affording food and air to the 

 little organised being. 



Dr. Carpenter believes, "The Volvoeinece, whose vegetable 

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



T 2 



