CCELOBLAST^ OR NON-CELLULAR PLANTS. 109 



to this condition of affairs, the whole plant may be considered as a single cell, or 

 as a uni-cellular plant. It affects the fact little, that under certain circumstances, at 

 particular places of such a plant, transverse septa arise in the vesicle. The main 

 point is, that growth, i.e. the increase in volume and external configuration, is 

 not here accompanied by corresponding cell-divisions as in other plants. So much 

 the more remarkable appears now the fact, established by Schmitz since 1878, 

 that in the protoplasm of these CceloblastcE numerous, even hundreds and thousands 

 of cell-nuclei are contained, which, with the advancing growth of the plant, are 

 multiplied by division, and obtain a definite arrangement within the protoplasm ; 

 thus behaving in a certain measure as if it were simply that the corresponding 

 partition-walls are not formed. This impression obtains in importance still more 

 in that, according to Schmitz, the cell-nuclei are most numerous at the growing 

 point of the vesicle, thus behaving as in the growing point of a cellular plant. 

 Nevertheless, it is not at all probable that the CaloblastcB are degraded or reduced 

 forms — i.e. we cannot well assume that they have arisen from proper cellular 

 plants by the cell-division, assumed as formerly existing, having ceased to develope 

 partition-walls. Be that, however, as it may, the fact remains for physiological 

 consideration that in the protoplasm of these plants a certain quantity of nuclear 

 substance (especially the nuclein characteristic of it) is distributed in formed 

 portions and at small intervals, and is especially aggregated in the growing 

 points. From this fact, we obtain once more, as we have already obtained from 

 other sides, a certain insight into the true significance of the cellular structure 

 of plants. We need only imagine in a not too complex cellular plant 

 (a higher Alga, a Moss, or even a vascular plant) that in the substance enveloped 

 by the outer walls of the epidermis, the cell-walls are simply wanting; whereas 

 the protoplasm, with the cell-nuclei distributed in it, behaves essentially just 

 as if these cell-walls were present. Thus we have, on the whole, the structure 

 of a Cceloblasi. On the contrary, we need only imagine the inner cavity of 

 such a Cceloblast to be divided up by numerous transverse and longitudinal 

 partition-walls into very numerous small chambers, each of which encloses one 

 or several of the cell-nuclei present, and we should thus have an ordinary cellular 

 plant. It is however very easily intelligible that not only the solidity, but also the 

 shutting off of various products of metabolism, the conduction of the sap from place 

 to place, and so forth, must attain greater perfection if the whole substance of 

 a plant is divided up by numerous transverse and longitudinal walls into cell- 

 chambers sharpl}' separated off from one another. 



