Organisms Consisting of Ojie Cell 235 



such as an air bubble, or advance by springs, which recall 

 those of a hunting spider." - The rapid movement ahead, 

 running against obstacles, backing off, clianging directions, 

 and turning around, remind one of the performances of an 

 ant under similar surroundings, flennings' statement that 

 they are "usually found running about on the bottom, or 

 on the surface of objects in the water," ^ is no more a figure 

 of speech than would be a similar remark about a rabbit.* 



FIGURE 5. STYLOXYCHIA MYTILUS ( AFTER Pt'tTER). 



With reference to their food habits, Maupas's characteriza- 

 tion of them as "hunter ciliates," is truly descriptive. 



By contrast the movements of Stenostoma are slow and 

 simple indeed. In it locomotion is accomplished almost en- 

 tirely by surface cilia, and the well-nigh complete absence 

 of differentiation among these, as contrasted with the high 

 degree of differentiation and specialization of the cilia of 

 Stylonychia, may be taken as a reliable index to the dif- 

 ference in locomotor activities of the two creatures. 



(h) Comparison of a Radiolarian and a Jelly-fish 



Carrying the comparison of unicellular, "simple" or "un- 

 true" animals, with multicellular, "complex," "true," ani- 

 mals still farther, we will take up a Radiolarian for brief 

 consideration. Non-technical readers are particularly urged 

 to look througli tlie volume of 140 quarto plates which il- 

 lustrate Haeckel's great Challenger Report on tliis group. 



* Jenninpjs copies this din gram from Piitter showing a Sfylonyrhia 

 "creeping- along tlie surface," uiiich sliows well the "belly" and the 

 "back" sides of the creature and the way in which it uses its cilia as legs. 



