162 THE SCIENCE OF LIFE. 



2. The MONERA of Prof. Haeckel, if the group shall be 

 accepted by naturalists, will include the simplest proto- 

 zoans, cr those in which the entire living body is a mere 

 particle of bioplasm, without nucleus, vacuole, invest- 

 ment, or other structure, yet capable of bioplasmic mo- 

 tions and other functions. Bathybius, referred to in 

 Chap. IV, Sec. 3, was supposed to be of this class. 



3. The GREGARINID^: are parasitic. Each consists 01 

 a single cell, which passes through changes similar in 

 many respects to Protophytes. It becomes globular and 

 encysted in a horny envelope, and the inclosed bioplasm 

 breaks up into particles which become " pseudo-navicel- 

 lae," or forms similar to the Navicula of the family Dia- 

 tomaceae. It is not unlikely that the Gregarince are but 

 phases in the life-history of other parasitic worms. 



4. RHIZOPODA. The Rhizopods, or root-footed Pro- 

 tozoans, (rhiza, a root, and pous, foot,) are characterized 

 by the power of spontaneously throwing out delicate 

 processes of their bioplasm, called pseudopodia, or false 

 feet, for prehension or locomotion. They have no cilia. 

 Dr. Carpenter has divided the class into three orders : 

 I. Reticularia, whose bodies are indefinite extensions oi 

 viscid bioplasm, freely branching and subdividing into 

 fine threads, but readily coalescing when they come into 

 contact. 2. Radiolaria, whose bioplasm has an invest- 

 ing membrane of formed material which prevents the 

 coalescence of the radiating or rod-like extensions of 

 the pseudopodia. 3. Lobosa, whose bioplasm has an in- 

 vesting membrane, or ectosarc, and whose false feet are 

 lobose extensions of the body itself. 



In the first order, that of reticularian rhizopods, we 



