82 PLANT-ANIMALS [CH. 



conclusion that this animal does not take up solid food. 

 A similar apparent total abstinence has been recorded 

 in cases of other animals which contain green or 

 yellow cells not unlike those which occur in our 

 plant-animals. Thus no food has been seen in the 

 bodies of certain adult Radiolaria, Ciliata, Hydro- 

 corallines and Madreporaria, and in all these animals 

 from which remains of food are absent, coloured cells 

 are present. Hence the natural inference has been 

 drawn that such animals subsist on the food-materials 

 manufactured synthetically by their green or yellow 

 cells. 



If, however, the evidence which we have now to 

 bring forward with respect to C. roscoffensis is 

 applicable to the other green- or yellow- celled 

 animals, then, though the conclusion may contain 

 a large measure of truth, the premise on which that 

 conclusion is based is erroneous. 



When referring to the abstemious habit of 

 C. roscoifensis we were careful to state that it is the 

 mature animal which does not take up solid food. 

 As a matter of fact, from the time of hatching to 

 the period of maturity, C. roscoffensis feeds, and 

 feeds voraciously. Indeed, its catholicity of taste 

 is remarkable. Diatoms, unicellular algse, spores of 

 various kinds and, in the absence of more nutritious 

 substances, grains of sand are swallowed with avidity 

 (cf. Fig. 14). Arrived at maturity, it ceases to ingest 



