PROTOZOA AND SPONGES 425 



I see an object slowly creeping along the glass, which 

 will be just the thing for our purpose. It is the Proteus 

 (Amoeba diffluens). Let me put on a higher power, and 

 submit it to your observation. 



You see a flat area of clear jelly, of very irregular 

 form, with sinuosities and jutting points, like the outline 

 of some island in a map. A great number of minute 

 blackish granules and vesicles occupy the central part, 

 but the edges are clear and colorless. A large bladder 

 is seen near one side, which appears filled with a subtile 

 fluid. 



But while you gaze on it, you perceive that its form is 

 changing; that it is not at two successive moments of ex- 

 actly the same shape. This individual, which, when you 

 first looked at it, was not unlike England in outline, is 

 now, though only a few minutes have passed, something 

 totally different; the projecting angle that represented 

 Cornwall is become rounded and more perpendicular; the 

 broken corner that we might have called Kent has formed 

 two little points, up in the position of Lincolnshire; the 

 large bladder which was in the place of the Eastern coun- 

 ties is moved up to the Durham coast, and is, moreover, 

 greatly diminished; and other like changes have taken 

 place in other parts. 



Lo! even while speaking of these alterations, they have 

 been proceeding, so that another and a totally diverse out- 

 line is now presented. A great excavation takes the place 

 of Dorset; Kent is immensely prolonged; the bladder has 

 quite disappeared, etc. ; but it is impossible to follow 

 these changes, which are ever going on without a mo- 

 ment's intermission, and without the slightest recognizable 

 rule or order. The projections are obliterated or exagger- 



