THE MECHANISM OF LIFE 519 



They cease only with the consumption of these substances. 

 These processes constitute the first group. Those constituting 

 the second group are not immediately dependent upon the presence 

 of nuclear substances. That such processes exist is shown by the 

 observations made byKlebs ('87) in plasmolysed cells of Spirogyra, 

 which Gerassimoff ('92) has completely confirmed. When by 

 plasmolysis in a 16 per cent, solution of cane-sugar Klebs caused 

 the cells of a thread of Spirogyra to break up into protoplasmic 

 lumps, bits of protoplasm frequently appeared that possessed 

 shreds of the chlorophyll-band but no nucleus. By employing 

 narcotics upon cells of Spirogyra that were undergoing division 

 Gerassimoff ('97) has recently obtained cells completely destitute 

 of a nucleus. Under favourable conditions these non-nucleated 

 masses of protoplasm in Klebs's experiments continued to live for 

 weeks. As has already been seen, in contrast with nucleated 

 masses they had lost the power of forming a new cellulose- 

 membrane. But they exhibited other vital phenomena unchanged. 

 For example, when put into the dark, they consumed completely 

 the starch that was contained in them, and, when in the light, 

 they formed new starch in case they still possessed chlorophyll. 

 In other words, the synthesis of starch from carbonic acid and 

 water, and the further consumption of starch is in a certain 

 degree independent of the influence of the nucleus. We say " in 

 a certain degree," for, if the non-appearance of other phenomena 

 caused by the removal of the nucleus has reached a certain 

 extent, evidently the starch-building chlorophyll-bodies will share 

 in the disorder ; they will experience changes, will form starch no 

 longer, and will finally perish. In the case above mentioned this 

 came in relatively late, frequently not until after several weeks. 

 In so far, therefore, as the metabolism of the chlorophyll-bodies 

 is disturbed along with the disturbance of the whole metabolism 

 by the removal of the nucleus, the formation of starch is in a 

 certain sense, but only indirectly, dependent upon the nucleus. 



While non-nucleated masses of protoplasm in plant-cells, in 

 case they still possess chlorophyll, split up carbonic acid and pro- 

 duce starch synthetically, they are also able to respire for a long 

 time. The proof of the fact that respiration continues in such 

 pieces to the same extent as in nucleated pieces or whole cells, 

 is afforded by the following experiment. 1 We place in a pendent 

 drop in Engelmann's gas-chamber 2 a number of nucleated and 

 non-nucleated pieces of Infusoria together with uninjured in- 

 dividuals, and let a stream of washed hydrogen pass through the 

 chamber from a Kipp's apparatus (Fig. 258) ; in a short time this 

 forces out the air contained in the chamber. As a rule after five 

 or ten minutes we see the non-nucleated and the nucleated pieces 

 and the uninjured Infusoria begin to undergo granular disin- 

 1 Cf. Verworn ('91). 2 Cf. p. 283. 



