140 The Living Plant 



over others which might be chosen in this, that while compara- 

 tively easy to obtain, their protoplasm exhibits a streaming 

 motion, which, though often slow and difficult at first to detect, 

 nevertheless when seen forms a valuable proof of its living condi- 

 tion. The rather inconspicuous grayish-granular, translucent, 

 semi-fluid appearance here presented inside of the cells is repre- 

 sentative of the aspect of protoplasm in general. The granular 

 look is due largely to the presence of food granules, which in 

 some cases are absent, leaving the protoplasm so nearly trans- 

 parent that it can hardly be seen at all unless stained by some dye, 

 while in other cases the granules are so plenty as to give the proto- 

 plasm an appearance of solidity. Moreover, as these granules 

 consist largely of protein which has a slight yellowish color, they 

 give to protoplasm in dense masses a distinctly yellowish or 

 brownish-yellow tinge; and this is the cause of the yellow color 

 which shows so plainly through the tips of white roots, and of 

 the brownish-yellow of the interior of young ovules. In the hairs 

 supposed to be lying before the reader, the protoplasm is obviously 

 soft enough to flow freely, though it is not wholly a fluid; and it 

 is known to possess about the consistency of a soft jelly. Indeed, 

 if one were to imagine an uncolored jelly, somewhat too soft to 

 retain the form of its mold and all clouded instead of quite clear, 

 hi other words just the kind of jelly that the thrifty house- 

 keeper doth most despise, he would have a very good idea of the 

 protoplasm of these hairs. In some plant tissues the substance 

 is still softer and almost a liquid; in others it is firmer, to such a 

 degree that in seeds it becomes tough and hard as horn, though 

 never approaching the hardness of ivory, as a prominent diction- 

 ary says that it does. The visible streaming of the protoplasm 

 in these hairs, however, is not typical, for while in some kinds 

 the streaming is even more active, generally it is very much slower, 

 and commonly is imperceptible; so that the reader must not 

 allow the motion to become too prominent a feature of his vis- 

 ualization of plant protoplasm. A white-granular, slow-moving 



