PLANT DISEASE 



must necessarily fail to assimilate the requisite 

 quantity of iron, and will consequently have a 

 tendency to become anaemic, a condition as 

 formidable to health in the animal as is chlorosis 

 in the plant, as is recognized by various authori- 

 ties. A brief survey of the construction and 

 functions of the haemoglobin will make this 

 clear. 



In Animal Physiology, p. 119, W.. S. Fur- 

 neaux says 



" The colour of the blood is due to the pres- 

 ence of a nitrogenous substance, called haemo- 

 globin, in the red corpuscles. This substance 

 contains a considerable proportion of iron 

 oxide." 



Again, in the Encyclopaedia Britannica, 

 article " Iron, Therapeutic Uses of," vol. xiii. 

 P. 359 we read 



"If the haemoglobin of the blood fall below 

 a certain standard, the supply of oxygen 

 necessary to healthy tissue changes in brain, 

 nerve, muscle, etc., becomes too limited, and 

 the changes will be imperfectly performed, 

 hence defective vitality general or local." 



