FlG. i. -Living Eugtenee forming a network in a vessel about half an inch deep 



(From Phil. Trans. B, vol. 201.) 



C f T 1 - r ~rT "HTTTTTT t 1 M & 



Fig. 2. — Euglena viridis, in a tube about 7 mm. in diameter placed in a 



horizontal position. 



a, seen from the side ; b, the same tube from above ; c, shows an earlier stage of the aggregation. 



(From a drawing, natural size.) 



a I) 



Fig. 3. — From photographs, natural size, showing the aggregation of Euglena viridis 



in a glass vessel T % in. deep placed in a horizontal position in the dark. 

 a, shows the formation of the network two and a half minutes after being placed in the dark ; b, shows 



the breaking up into separate groups four minutes later. (Phil. Trans. B, vol. 201.) 

 p. 300] 



