Inasmuch as this substance manifestly was soft, Dujardin proposed for it the name of sarcode, from the Greek, meaning _soft_. Thus we see that the substance protoplasm was for the first time brought very definitely to the attention of naturalists through the study of animal forms. For some time it occupied a position of isolation, but ultimately became recognized as being identical with a similar substance that occurs in plants. At the time of Dujardin's discovery, sarcode was supposed to be peculiar to lower animals; it was not known that the same substance made the living part of all animals, and it was owing mainly to this circumstance that the full recognition of its importance in nature was delayed. The fact remains that the first careful studies upon sarcode were due to Dujardin, and, therefore, we must include him among the founders of modern biology. [Illustration: Fig. 83.-Purkinje, 1787-1869.] Purkinje.--The observations of the Bohemian investigator Purkinje (1787-1869) form a link in the chain of events leading up to the recognition of protoplasm. Although Purkinje is especially remembered for other scientific contributions, he was the first to make use of the name protoplasm for living matter, by applying it to the formative substance within the eggs of animals and within the cells of the embryo. His portrait is not frequently seen, and, therefore, is included here (Fig. 83), to give a more complete series of pictures of the men who were directly connected with the development of the protoplasm idea. Purkinje was successively a professor in the universities of Breslau and Prague. His anatomical laboratory at Breslau is notable as being one of the earliest (1825) open to students. He went to Prague in 1850 as professor of physiology. [Illustration: Fig. 84.--Carl Nägeli, 1817-1891.]