IO6 THE OCEAN WORLD. 



genus Paramecium, he adds, that in former writers a link was wanting, 

 viz., tracing the young actually hatched from the egg of a Planarian. 

 " This deficiency," he says, " I can now fill. It is another Infusorium, 

 a genuine Opalina. With such facts before us, there is no longer any 

 doubt left respecting the character of all these Polygastria; they 

 are the earliest larval condition of worms.*' 



