SPONGES. 



HAVE placed Sponges in my last chapter, 

 and in doing so I am apparently following 

 the old zoological routine, which regards 

 these singular beings as the last link of the 

 animal chain the link which joins the animal to 

 the vegetable world ; but this surely is not a fact ! 

 Sponges are evidently more closely allied to Polypes 

 than to such animalcules as the Monads. Indeed, 

 had it been practicable, I would willingly have con- 

 densed Polypes, Infusoria, and Sponges into one 

 chapter. But the reason why Infusoria have been 

 lately placed before Sponges by most zoologists 

 appears to be, that as the former class becomes 

 better known, and the organization of its species 

 more thoroughly investigated by means of the 

 powerful microscopes constructed at the present 

 day, the complication of their structure excites 

 astonishment, and, as we have already seen, many 

 genera are being placed much higher in the series 

 than the places which were formerly assigned to 



