ORIGIN AND NATURE OF LIFE. 335 



Now, however, all this is changed. Protoplasm, 

 it has been discovered, is not a single chemical com- 

 pound with a definite and constant molecular struc- 

 ture, as was formerly taught. It is something vastly 

 different. Microscopy and micro-chemistry have 

 demonstrated that it is composed of a dozen or more 

 substances, all of the greatest complexity. Far from 

 being a single, homogeneous, transparent, structure- 

 less jelly, as described some years ago, and as still 

 conceived by many who glibly talk about it, proto- 

 plasm, on the contrary, is a most highly organized 

 structure, composed of complex liquid matter, gran- 

 ules, fibres, tubules, nuclein, and exhibiting in the 

 living organism the most marvelous properties and 

 the most wonderful activity. Indeed, protoplasm 

 is a word that has almost vanished from the nomencla- 

 ture of the cytologist. And in its place we have a 

 score or more of new terms, to designate the constit- 

 uents of what was but a few years ago regarded, even 

 by the ablest exponents of science, as a single chem- 

 ical compound of uniform composition. Thus, in 

 lieu of protoplasm, we now have nuclein, pyrenin, 

 and nucleoplasm ; paranuclein, amphipyrenin, and 

 karyoplasm, not to mention other compounds equally 

 remarkable and complicated. 



Such being the case, there is obviously no more 

 hope of the chemist eventually being able to manu- 

 facture protoplasm, than there is of his being able to 

 produce a polyp or a sea-urchin. He may build up 

 from their simple elements complex compounds like 

 urea, formic acid and indigo, because these have a 

 definite molecular composition, but he can no more 



