14 



THE CELL AND PROTOPLASM 



space or chamber was regarded as the 

 essential feature. Many of the early stu- 

 dents of cells recognized that they con- 

 tained or were embedded in a semi-fluid or 

 gelatinous substance. Wolff, in 1759, said : 



Every organ is composed at first of a little mass 

 of clear, viscous, nutritive fluid, which possesses no 

 organization of any kind but is at most composed 

 of globules. In this semi-fluid mass cavities are 

 developed; these, if they remain round or polygo- 

 nal, become utricles (cells) ; if they elongate, 

 vessels. 



In 1809, Oken wrote : 



Organic nature has for its basis an infinity of 

 email vesicles. These little bladders arise from 

 original, semi-fluid globules of ' ' Urschleim. ' ' 5 



Many botanists of that period, including 

 Schleiden, described the cell contents as 

 ** plant slime," "mucus," or "mucilage"; 

 Mirbel called it "cambium"; Nageli, in 

 1844, considered it a mixture of gum, sugar 

 and proteid. 



In 1835, Felix Dujardin (1801-1860) 

 proposed the name "Sarcode" for the semi- 

 fluid material of the bodies of Foramen- 

 ifera, which other observers of Protozoa 

 had called "living jelly." Dujardin de- 

 scribed Sarcode as a "substance glutinous, 

 perfectly homogeneous, elastic, contractile, 

 diaphanous, without any trace of organiza- 

 tion, fibers, membranes, or appearance of 

 cellulosity, " 



In 1840, Purkinje (1787-1869) used the 

 name "protoplasm" to designate the form- 

 ative material of embryos of animals, and, 

 in 1846, von Mohl applied this word to the 

 living substance in the embryonic cells of 

 plants. From this supposedly primordial 

 and undifferentiated protoplasm of embry- 

 onic cells he derived the thin pellicle of 

 protoplasm which lines the cell membrane 

 and surrounds the cell sap in adult plant 

 cells; this layer he called the "primordial 

 utricle," a name which has persisted in 

 botany until the present. 



The streaming of protoplasm which was 

 first seen and described in plant cells, in 

 1772, by Bonaventura Corti and then by 

 Treviranus, in 1807, was found by von 

 Mohl to be located in this primordial 



5 Quoted from Haeckel's History of Creation. 



utricle. As early as 1830 Meyen attributed 

 this circulation within the cell to the power 

 of the fluid itself since it is moved by no 

 organs. He thought the circulation of the 

 cell contents in plants was suggestive of 

 the revolution of the planets around the 

 sun and he spoke of its being caused by "a 

 gravitation of plants." Cohn in 1848 

 showed that plant protoplasm is similar to 

 animal sarcode, and in 1859 DeBary 

 proved that the sarcode of protozoa and the 

 protoplasm of plants are essentially similar. 

 Finally, Max Schultze in 1861 established 

 the essential resemblance of sarcode with 

 the protoplasm of all animals and plants. 

 Thus was established what 0. Hertwig, in \/ 

 1892, called the "protoplasm theory," 

 which is a much more fundamental gen- 

 eralization than the cell theory. In 1874, 

 the English histologist, Lionel Beale, called 

 living matter "bioplasm," and this name 

 was regarded by some persons with vitalist 

 leanings as less objectionable than proto- 

 plasm, since it included life as a character- 

 istic part of the substance. 



As is often the ease when some great 

 theory is first proposed, this protoplasm 

 theory was at first carried too far. By 

 some persons it was supposed that proto- 

 plasm was a definite chemical compound, 

 a life substance, and that the solution of 

 all the problems of all life was to be found 

 in the structure and functions of this one 

 compound; but soon it was realized that 

 protoplasm is no single chemical substance 

 but a combination of many chemical com- 

 pounds and that it differs in every species 

 of animal or plant and, indeed, in every 

 different kind of cell. 



Gradually the view developed that proto- 

 plasm is not merely a combination of many 

 of the most complex chemical compounds 

 that are known, but that it is a complicated 

 organization, or organism, and that to 

 identify life with protoplasm is no more 

 revolutionary than to identify it with plant 

 or animal. In this protoplasmic organiza- 

 tion the constituent parts that were first 

 recognized were the nucleus and its sur- 

 rounding material; the latter was named 

 "cytoplasm" by Kolliker, in 1862, and 

 "plasson" by Van Beneden, in 1871. The 



