Thk Microscope. 107 



We are well aware that it is generally believed that the term 

 protoplasm has been introduced by von Mohl. We also believe 

 that von Mohl was perfectly honest, and knew not the prior 

 existence of this term when, in 1846, he thus expresses himself 

 in the " Botanische Zeitung : " "I feel myself authorized to give 

 the name of protoplasma to tliat nitrogenized, semi-fluid sub- 

 stance, colored yellow by iodine, contained in the cellular cavity,, 

 and which supplies the material for the formation of the primor- 

 dial utricle and the nucleus." 



However this may be, it is nevertheless certain that it was a 

 happy conception of von Mohl's to use the same term, although 

 unknown to him, in order to indicate or at least to foreshadow 

 the identity existing between the animal and vegetable cell- 

 content. 



II. THE PROPERTIES OF LHING MATTER. 



F. Dujardin, in 1835, was the first to make known the proper- 

 ties of living matter. Little was left by him to be added to his dis- 

 coveries, except probably to generalize and extend his researches 

 to the protoplasm of both kingdoms. The following quotation 

 though somewhat lengthy will give the reader a good idea of 

 Dujardin's notion. 



" I propose to call sarcode what other investigators have called 

 living jelly, that glutinous, diaphanous and homogenous matter 

 which refracts light a little more than water, but less than oil ; 

 which is elastic and contractile, and capable of forming, spontan- 

 eously spherical cavities in its interior, called ' vacuoles,' so as to 

 make a sort of cage with transparent walls. . . Sarcode is in- 

 soluble in water ; but when left in it for a long time, it gradually 

 decomposes, and leaves a granular residuum. Potash does not 

 dissolve it at once, as it does mucus and albumen, but merely 

 accelerates the decomposing action of water, and gives it a white 

 and opaque appearance. Its properties therefore are entirely 

 different from tliose of other substances with which it could have 

 been confounded ; first, because it is distinguished from albumen 

 in not being soluble in water, and secondly, by its insolubility 

 in potash it is at once distinguished from mucus, gelatin, etc. . . 

 The most simple animals, such as the Amoebse, Monads, etc., are 

 composed wholly, at least in a))pearance, of this living jelly. In 

 the higher Infusoria it is enclosed in a loose tegument, w'hich 

 appears to surround it like a network, and from which it may 



