So TOILERS IN THE SEA. 



Although, in some minute points of its history, the 

 naked Actinophrys is not identical with the shell- 

 bearing Polycystins, the knowledge of the one may 

 be helpful to the knowledge of the other, and it must 

 be remembered that it is only in recent times, con- 

 sequent on great improvements in the microscope, 

 that any real history of the structure and habits of 

 such minute organisms has been traced, and in this 

 direction much still remains to be accomplished. 

 Difference of opinion as to the interpretation of ap- 

 pearances still prevails, and an instance of this kind 

 occurs in regard to the inception of food, for, on this 

 point, Dr. Wallich says, that " during many years' 

 study of the Foraminifera, Polycystina, and all pelagic 

 Rhizopods, in their living condition, notwithstanding 

 a keen look-out for an example, he has invariably 

 failed to discover a single instance in which there 

 was satisfactory evidence that solid matter had been 

 taken into the substance of the body as food. This 

 fact derives additional weight from the circumstance 

 that some of these Rhizopods occur at times in 

 immense numbers. It is difficult, therefore," he 

 thinks, " to conceive how all should present themselves 

 devoid of everything like solid incepted matter, were 

 such matter essential to their existence. For it 

 must be manifest that, as generally attributed to the 

 Rhizopods, the processes referred to partake of the 

 miraculous, and, what is particularly notable, that it 



