GENERAL PEOPEETIES OF LIVING MATTER. 19 



showed, in 1861, that changes of form, locomotion, and division 

 are impossible to corpuscles surrounded by a resistant mem- 

 brane ; he maintained that the smallest individual elements of 

 organisms are lumps of a jelly-like matter endowed with life, for 

 which he proposed, for good reasons, in accordance with the 

 German botanist, Hugo von Mohl, the term " protoplasm." This 

 jelly-like substance is identical with Dujardin's " sareode." Max 

 Schultze was the first to announce that the living matter of the 

 infusion-animalcules and that of the cells of all animals are one 

 and the same substance. The cell consists, according to this 

 observer's views, of a minute particle of protoplasm, in which 

 there are imbedded the nucleus and granules. In the same year 

 (1861), E. Briicke, of Vienna, though accepting Max Schultze's 

 views, asserted that the nucleus is not an essential part of the 

 cell, as he knew of many living lumps without any nucleus. 

 Briicke defined the " cell," for which he also proposed the name 

 of " elementary organism," to be a structureless lump of pro- 

 toplasm; though fully aware of the necessity of the existence of 

 some structure, as in every substance, he regarded the structure 

 of the cell as imperceptible to our senses. S. Strieker, in 

 accordance with Briicke, in 1868, explained that the cell is 

 nothing but a particle of structureless protoplasm, usually con- 

 taining granules, but that these granules are not essential 

 characteristics. He especially examined the form-elements of 

 the ovula of frogs while studying their development, and 

 observed in these elements hyaline flaps, which he took for pure 

 protoplasm, whereas the greater part of the protoplasm was 

 filled with granules, or particles of yoke. The fact that every 

 living lump is capable of taking in foreign minute corpuscles, 

 granules of carmine or aniline, for instance, from without, led 

 him to the conclusion that protoplasm, perhaps, is devoid of any 

 visible structure, while the visible granules are secondary prod- 

 ucts of the protoplasm, or foreign substances accidentally taken 

 into the interior of the protoplasmic lump. S. Strieker, in his 

 "Histology," discusses the question, "how large the lump of 

 protoplasm must be to be entitled to the name of 'cell/" and 

 comes to the conclusion that we should call a living corpuscle a 

 "cell" only when we perceive in it the properties of a living 

 organism viz., growth, motion, and reproduction. Lionel Beale 

 (1860), independently of Max Schultze's doctrine, announced sim- 

 ilar views, arriving, however, at conclusions quite different from 

 those of German biologists. Apparently his microscopes, al- 



