p II^MATOdOdCUS LESS. 



can be carried on. This may be expressed by saying that 

 Haematococcus, in common with other organisms contain- 

 ing chlorophyll, is supplied with kinetic energy (in the form 

 of light or radiant energy) directly by the sun. 



As in AmcEba, destructive metabolism is constantly going 

 on, side by side with constructive. The protoplasm becomes 

 oxidized, water, carbon dioxide, and nitrogenous waste 

 matters being formed and finally got rid of. Obviously 

 then, absorption of oxygen must take place, or in other 

 words, respiration must be one of the functions of the pro- 

 toplasm of Hgematococcus as of that of Amoeba. In many 

 green, i.e., chlorophyll-containing, plants, this has been proved 

 to be the case ; respiration, i.e., the taking in of oxygen and 

 giving out of carbon dioxide, is constantly going on, but 

 during daylight is obscured by the converse process — the 

 taking in of carbon dioxide for nutritive purposes and the 

 giving out of the oxygen liberated by its decomposition. In 

 darkness, when this latter process is in abeyance, the 

 occurrence of respiration is more readily ascertained. 



Owing to the constant decomposition, during sunlight, of 

 carbon dioxide, a larger volume of oxygen than of carbon 

 dioxide is evolved ; and if an analysis were made of all 

 the ingesta of the organism (carbon dioxide p/us mineral 

 salts J>/us respiratory oxygen) they would be found to con- 

 tain less oxygen than the egesta (oxygen from decomposition 

 of carbon dioxide p/us water, excreted carbon dioxide and 

 nitrogenous waste) ; so that the nutritive process in Hgema- 

 tococcus is, as a whole, a process of deoxidation. In 

 Amoeba, on the other hand, the ingesta (food plus respi- 

 ratory oxygen) contain more oxygen than the egesta (faeces 

 p/us carbon dioxide, water, and nitrogenous excreta), the 

 nutritive process being therefore on the whole one of 

 oxidation. This difference is, speaking broadly, character- 



