PHYLUM PROTOZOA. FLAGELLATES 



45 



One cyst usually contains two euglenas, al- 

 though further multiplication by longitud- 



inal division may produce 4, 16, or 32 young 

 euglenas in a single cyst. 



Stages In longitudinol fission 



Euglenoid movement 



Division v/ithin a cyst 



Figure 20. Reproduction and euglenoid movement in Euglena vhidis. 



OTHER MASTIGOPHORA 



The relations of flagellates to man are dis- 

 cussed in Chapter 7, where accounts will be 

 found of species that live in drinking water, 

 in the soil, and in the blood streams and in- 

 testines of human beings. A few other types 

 of particular interest are as follows. 



Chilomonas (Fig. 21) is a species that is 

 very common in nature and in laboratory 

 cultures; it constitutes a large part of the 

 food of Amoeba proteus. It is about 35 

 microns long and has two flagella at the an- 

 terior end. It does not possess chromato- 

 phores, but absorbs nutriment through the 

 surface of the body. 



Among the flagellates that live in the sea 

 are species of the genus Noctiluca (Fig. 21), 

 which sometimes occur in such enormous 



numbers that, due to their orange color, the 

 water looks like tomato soup. One quart of 

 sea water may contain more than three mil- 

 lion individuals. Even more striking is the 

 appearance of the sea when one travels over 

 it at night. Noctiluca is luminescent and 

 glows with a bluish or greenish light when 

 agitated. One can read the time on his 

 watch when it is held a foot away from a 

 glassful of these flagellates. Incidentally, this 

 light is not accompanied by production of 

 heat, and hence it is generated without the 

 loss of heat energy, which is something man 

 has not been able to do in making artificial 

 light. Many other animals and certain plants 

 possess a similar power of producing light 

 without wasting energy, for example, the 

 fireflies and their larvae, the glow^'orms. 

 Gymnodinium (Fig. 21) is a dinoflagellate 



