64 



ZOOLOGY 



SECT. 



paramylum (H, p.), a carbo-hydrate allied to starch. In contact 

 with the reservoir is a bright red speck, the stigma (pg^), formed of 

 a pigment allied to chlorophyll and called JicematocJirome. It seems 

 probable that the stigma is a light-perceiving organ or rudimentary 

 eye. 



Euglena is nourished like a typical green plant : it decomposes 

 the carbon dioxide dissolved in the water, assimilating the carbon 

 and evolving the oxygen. Nitrogen and other elements it absorbs 

 in the form of mineral salts in solution in the water. But it has 

 also been shown that the movements of the flagellum create a 

 whirlpool by which minute fragments are propelled down the 



C.VTZC 



FIG. 46. Eugleua viridis. A D, four views illustrating cuglenoid movements; Band H, 

 enlarged views ; F, anterior end further enlarged ; G, resting form after binary fission ; c. vac. 

 contractile vacuole in H, reservoir in E and F ; cy. cyst ; jl. flagellum ; m. mouth ; nv. nucleus ; 

 ces, gullet ; p. paramylum bodies ; py. pigment spot ; r. (in H), reservoir. (From Parker's 

 Biology, after Kent and Klebs.) 



gullet and into the soft internal protoplasm. There seems to be 

 no doubt that in this way minute organisms are taken in as food. 

 Euglena thus combines the characteristically animal (holozoic) with 

 the characteristically vegetable (holophytic) mode of nutrition. 



Sometimes the active movements cease, the animal comes to 

 rest and surrounds itself with a cyst or cell-wall of cellulose (G), 

 from which, after a quiescent period, it emerges to resume active 

 life. It is during the resting condition that reproduction takes 

 place by the division of the body in a median plane parallel to 

 the long axis (G). Under certain circumstances multiple fission 

 takes place, and flagellulaB are produced, which, sometimes after 

 passing through an amoeboid stage, develop into the adult 

 form. 



