CRUSTACEA AND MOLLUSCS 235 



body out of the number of substances found in nature, 

 and who converts them into dead albumen by 

 progressive combinations ? 



First of all, we must explain that the forces that can 

 do this are only present in the plants. These alone 

 have the power to select the requisite elements for 

 making albuminoids out of water, air, and earth ; 

 animals have lost this power. The latter must always 

 obtain their albumen ready made, and their biogens 

 will then convert it into living albumen. Animals 

 perish if only supplied with inorganic matter, as their 

 biogens then find no albumen that they can convert 

 into particles like themselves. They cannot make a 

 beginning with inorganic material, as their substance 

 has not the power to put it through the long series 

 of combinations that are necessary for the production 

 of an albuminoid. 



Thus the whole animal world is based on the plants. 

 These alone have retained the power to form living 

 matter out of inorganic substances ; they are now the 

 sole laboratory in which albuminoid substances are 

 prepared. This can be done, however, only by the 

 green plants ; the others, such as the fungi, need organic 

 nourishment, like animals. The green in the plant 

 consists of microscopically small granules of chlorophyll ; 

 they have the power, under the influence of sunlight, 

 of gradually creating organic matter from the necessary 

 elements of the air, earth, and water. The plants are 

 the foundation of life. They alone can cover the steady 

 return of living substance into inorganic matter, during 

 its disintegration, by re-forming organic from the 



