2 3 o SCIENCE PROGRESS. 



dissolve in water ; dead plasma on the other hand becomes 

 albumen and dissolves speedily. What that something is 

 I do not venture to suggest ; could we ascertain what it is, 

 no doubt we should have discovered the solution to the 

 riddle of life. Hertwig says that the structural elements of 

 protoplasm, be they filaments, or reticular, or lamellae, or 

 alveoli, or granules, or what else, have a fixed state of 

 aggregation. Protoplasm is no mixture of two immiscible 

 substances such as water and oil, but consists of a union of 

 fixed organic material particles with abundant water. This 

 is but a verbal statement of the facts and is no explanation, 

 but he adopts later on {Joe. tit., p. 49) Nageli's micellar 

 theory as an explanation. No doubt it is the best explana- 

 tion possible, but it again does not give more than a verbal 

 explanation of the remarkable and fundamental phenomenon 

 that protoplasm, be its structure what it may, does not when 

 alive dissolve in water, but when dead it becomes some- 

 thing else which readily dissolves, provided of course that it 

 is not killed by means which coagulate the albumens into 

 which it is converted at death. 



I shall recur again to the micellar theory, for the pre- 

 sent purpose it is sufficient to say that it is not inconsistent 

 with Biitschli's " Wabenlehre," 1 and might even be pressed 

 into service to explain why the plasma does not mix with 

 the watery alveolar contents without the necessity of calling 

 fatty acids to aid. 



Supported by these considerations, and by a considerable 

 mass of objective evidence, I venture to think that Btitschli 



1 Biitschli criticises the micellar theory and the analogous theory of 

 "inotagmas" put forth by Engelmann. He does not accept either, but 

 does not give in their place any theory of the ultimate compositions of the 

 substances which form the alveolar framework and contents, except that 

 (p. 309) he says, " a series of reflections . . . led me to suppose . . . that 

 the chemical basis of the framework substance must be formed by a body 

 which has arisen from a combination of albuminoid and fatty acid mole- 

 cules." Such a combination must mean the formation of a chemical unit 

 of a higher order than the molecules which enter into its composition, and 

 for my purposes such a chemical unit is a micella. In this limited sense 

 the acceptance of a micellar structure is not incongruous with the " Wa- 

 benlehre ". 



