218 president's address. 



shapes. If, however, a pressure be used, or still better, a 

 mixture of equal parts of glycerine and water be diffused 

 through it, a strong streaming movement will be seen ; but, in 

 my experience, in repeating the experiments, only when on a 

 warm stage of 50° C, and I find that amoeboid movements 

 rarely are seen except under pressure. 



It thus appears that we are dealing with a very fine froth, 

 consisting of a laige number of minute beads of soap dissolved 

 in water, and each enveloped by a thin wall of fluid oil. All 

 such films, when in contact, unite in many-sided figures, as on 

 the surface of the fluid from which a child is blowing bubbles, 

 or with which the work of the laundry is done. 



The minuteness of the space between the glass-surfaces 

 causes this mesh-work, so-formed, to take the appearance of a 

 complex cellular tissue, and there are thickenings which take 

 place in the cellular mesh which certainly have a granular ap- 

 pearance ; but, I may add, that no appearance in the colloid mesh, 

 whether granular or fibre-like or folded, appeared other than as 

 the result of minute hollow beads when sufficiently examined. 



There may be an interior relatively large vacuole, and a 

 cellular border with its walls more or less radially arranged, 

 and the whole may flow, retaining all its features. In the 

 drops also there are relatively powerful streaming movements 

 within, reminding us of streaming in both vegetable and 

 animal cells. These are best seen when the glycerine has 

 done its work upon the foam. 



It is, of course, explained that these internal movements 

 depend on surface tensions. The surface tension between the 

 oil and the solution of soap is not so great as that between the 

 oil and the water ; this ultimately accounts for the streaming 

 movements. 



From this it is argued that we have, only in a simpler form, 

 the extremely complex chemical conditions, and active altera- 

 tions of state constantly arising in protoplasm. It is contended 

 that altered tensions within and outside the cell constantly 

 arise, hence, mechanically at least, arise streaming, alteration 

 of place, and mutation of form. 



That all this is extremely ingenious and profoundly interest- 

 ing no one competent to judge will deny, and the repetition of 

 the experiments is fraught with pleasure and deep instruction. 

 But it would be a grave error to suppose that by any of these 



