397] 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 
whetlier it is cell-wall or living cell-contents that are being referred 
to under the name ofcell. 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 Ulothrix 
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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