897J CELL OR CORPUSCLE? 393 



It seems to me that there are only two possible ways of reform 

 open to us, and both are accompanied with grave difficulties. 



We may introduce that change from the word cell to that of 

 energid (Sachs) or biophor (Hansen), which, it has already been 

 pointed out, will bring countless troubles with it in respect to the old 

 and classical literature ; or we may effect an alteration in nomencla- 

 ture within the science of botany itself. Retaining the word cell to 

 express protoplasm and nucleus, we may bring in a new name for the 

 cell wall minus its living contents. Here also great confusion would 

 result to the older writings, but the confusion would be within a 

 more limited sphere. As we have already mentioned, it is in the 

 province of the vegetable kingdom that the difficulties with regard 

 to the meaning of the term 'cell' have arisen, and in reading the 

 older memoirs we are frequently brought to a pause to enquire 

 whether it is cell-wall or living cell-contents that are being referred 

 to under the name of cell. The perplexities accompanying a substi- 

 tute for the word cell in its significance of cell-membrane would, 

 therefore, not be so heavily felt as those associated with a new word 

 for the protoplasmic contents. The changes involved would be heavy 

 within their sphere (it is not simply the word cell but the compound 

 expressions which have been formed from it which would have to give 

 place to the new order of things), but still this range would be a 

 fairly limited one. It would be only the single science of botany, 

 already perplexed with difficulties of meaning and not the additional 

 provinces of zoology and animal (and human) physiology, which are 

 clear in their use of the word, which would suffer from the innova- 

 tion. What substitute might be employed for the word cell in its ap- 

 plication to the membrane and the cavity included by it, is not easy 

 to see — perhaps the word ' vesicula ' is not altogether inappropriate, 

 but if changes on these lines should ever prove applicable, it will 

 then be time enough to look about for a new term. 



The first alternative, which was mentioned above, is the one 

 which hitherto has alone been dealt with by biologists. 



Sachs, in his two notes in Flora (1892, 1895), has proposed 

 to call the nucleus, together with the protoplasm governed by it at 

 any time, an energid. If such an energid be included within a 

 membrane it is to be spoken of as a cell. The distinguishing 

 characteristic of an energid is the living element (protoplasm and 

 nucleus), whilst that of a cell is the membrane. 



From this point of view, therefore, the swarmspore of Ulothria 

 is an energid, whilst immediately that it forms a wall around itself 

 it reaches the further dignity of a cell : the elements of cork tissue 

 are also cells. In plants of the type of Vaucheria the protoplasm 

 is studded with nuclei, and the whole mass is enclosed within a single 

 cell-membrane. Each nucleus may be conceived as exerting its in- 



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