8 PLANT DISEASE 



carbon dioxide, and unless this is absorbed, 

 the necessary proteids are not formed. 



Animals, therefore, fed upon chlorotic food 

 cannot absorb the chemical constituents neces- 

 sary for health. 



In a later chapter I propose to go more fully 

 into the formation of the starch, sugars, fats, 

 proteids, and protoplasm formed from the 

 carbon dioxide taken up through the agency 

 of the chlorophyll and to show that it is im- 

 possible for a chlorotic food to be as rich in 

 these proteids, etc., as vegetable food which 

 contains a sufficient percentage of iron, and 

 consequently of chlorophyll. 



Another point to be considered in relation 

 to the haemoglobin is the important part it 

 plays in the absorption of oxygen into the 

 system. In the Encyclopaedia Britannica, vol. 

 xiii. p. 359, we read 



" Each corpuscle consists of a stroma, per- 

 meated by a red fluid, haemoglobin, which 

 has the remarkable property of readily com- 

 bining with either oxgyen or carbonic acid, 

 but so loosely that under slightly altered 



