EUGLENA VIRIDIS 51 



which it propels itself through the water ; also a red eye- 

 spot, and a number of minute bodies coloured with 

 chlorophyll. The cell membrane is elastic, enabling 

 the organism to assume curious forms. It is not com- 

 posed of cellulose. Within the body occur many 

 minute plates of paramylum, a substance allied to starch. 

 Euglena viridis multiplies either by lon- 

 gitudinal fission or by the formation of 

 cysts, within which a single cell divides 

 into two, four, or even more individuals. 

 In the matter of nutrition it seems that 

 Euglena can ingest tiny particles of food, 

 indicating an animal mode of feeding, 

 and also assimilate carbon dioxide and 

 form carbon compounds, a power indi- 

 cated by the chloroplasts and the 

 paramylum bodies; thus, it shows both 

 animal and plant characters. The ab- 

 sence of cellulose in the cell -membrane ^j^i^ (EmB!)! 



is noteworthy. Highly Maqhi- 



May we not regard Euglena as a by- '^^^' 



1 , ,. 1 , • , • a. Pigment spot: b, 



product of evolution, suggesting an a^ellarreservou-; 



ancestral stage in the rise of certain c, paramylum 

 green plants ? We do not suggest for a ^-"^^-^j; ^'^^ 

 moment that this organism is one which 

 itself anciently led on to higher forms; all we ven- 

 ture to submit is that it indicates a remote develop- 

 ment in the course of which primitive monads, 

 through the production of chlorophyll, gradually 

 assumed plant characters. Perhaps in Euglena the 

 animal and plant characters are fairly evenly balanced, 

 but we can imagine a series of developments leading to 



