i8 



THE INVERTEBRATA 



chemosynthesis by the use of energy obtained from reactions between 

 inorganic substances. Holophytic nutrition/ however, is found, among 

 protozoa, only in certain of the Mastigophora (see below). Of the 

 holozoic members of the phylum, some feed by amoeboid action. 



Fig. 13- 



- - - vib. 



_«L .^ha.lam. 



■- tl.fi. 



Fig. 14. 



ha.fi. 



Fig. 15- 



Fig. 13. Diagram illustrating the optical appearance given by a profile view 

 of cilia beating in metachronal rhythm. After Verworn. 

 Fig. 14. Three membranellae from the adoral wreath of Stentor. After 

 Doflein. ha.fi. basal fibre of the rhizoplast system; ha.lam. basal lamellae; 

 tl.fi. terminal fibres; vih. vibratile elements; the band beneath each of these 

 represents the fused basal granules of the constituent cilia. 



Fig. 15. Paramecium, showing the motorium lying near the vestibule, and the 

 fibrils which radiate outwards. After Rees. 



^ The nutrition of an organism is said to be holophytic when it is eflfected, 

 as in typical plants, by the building up of complex organic substances from 

 simple inorganic ones by use of the energy of certain of the sun's rays (photo- 

 synthesis). The radiant energy is obtained by means of the green, yellow, or 

 brown structures known as " chromatophores " or "chromoplasts" (e.g. the 



