ANIMAL AND VEGETABLE 



127 



If it were possible by any means to destroy all the other 

 tissues of such a plant as a large Euphorbia or Asclepias, 

 the entire form of the plant would still be preserved as a 

 mass of very fine threads of various thickness, representing 

 the ramifications of the original latex-cells ; just as the 

 injected vascular system of a vertebrate animal after the 

 removal of all other tissue allows the whole organisation of 

 the body to be recognised. . . . The laticiferous vessels 

 contain two essentially different groups of substances : 

 those which are again utilised in metabolism (proteids, 

 carbo-hydrates, fats, ferments), and those which must be 

 regarded as excreta useless in metabolism (resins, gums, 

 alkaloids, etc.). 



ANIMAL 



VEGETABLE 



Fig. 66. 



Injected blood-vessels of a human 

 muscle. (After Landois and Stir- 

 ling.) (Kolliker.) 



Fig. 67. 



Section from Scorzonera his- 

 panica showing reticulately united 

 latex vessels. (After Strasburger.) 



" The green vegetables are particularly rich in salts, 

 which resemble the salts of the blood ; thus, dry salad is 

 said to contain twenty-three per cent, of salts, which 

 closely resemble the salts of the blood." 



Given the necessary patience, I have no doubt that 



