TIIK NATl'RE OF DIATO:\I MOTION. II7 



Now as to the first question, it might be thought that the 

 answer is implied in the undisputed statement that diatoms 

 do move. If they move, not when currents of water wash 

 them along- or other organisms knock them about, but in the 

 absence of any disturbances of this sort, and in a regular and 

 characteristic manner, why is not this motion spontaneous ? 

 Why not indeed? The writer knows of no reason, and is 

 ready at once to say frankly, and shamelessly if you will, that 

 he has no doubt in the world about the essential spontaneity 

 of the diatom motion. The moving diatom gives the plainest 

 and most indisputable evidence that it is actuated by internal, 

 energetic, p/vtoplasiiiic stress. The evidence is many-sided. 

 It consists not only of the many obvious struggles against 

 obstacles of various sorts that chance puts in the path, but 

 also and especially of bio-chemical facts that would seem con- 

 clusively to correlate this activity with the motile activity of 

 protoplasmic organisms in general. Now when all the evi- 

 dence obtained gives such result, one is inclined to say that 

 the answer to the first question is obtained. But we have 

 still to reckon with the vast subtlety of the great intellects 

 that have set themselves of late to the task of abolishing the 

 fetish of " vital force." 



It would be impossible, at the present time, to go into the 

 broad question of the nature of vital phenomena in general. 

 There is no time to consider whether or not animals and 

 plants, one and all, are merely so many shuttlecocks, so many 

 footballs, so many packets of chemicals, all busily engaged in 

 ' ' reacting ' ' to this, that and the other bat, or kick, or string, or 

 other device brought to bear upon them by the great and wise 

 god " Knvironment." If, in the end, the ADuvba is shown to 

 be no more than an unusually persistent foam such as any one 

 can make with olive oil and potash ; -'= if, presently, by virtue 

 of some additionaj chemicals, these drops of foam can be 

 made to start out in search of food, absorb it when found, 



*0. Biitsclili : Protoplasm ami Microscopic Foams. Translated by 

 K. A. Minchin. London, 1894. 



