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being a treatment of the physiological relations of the proteins of 

 plants. In this place he introduces a discussion of the toxal- 

 bumins such as ricin, the exceedingly poisonous constituent of 

 the castor-bean, and he also treats of the precipitin and agglutinin 

 reactions of the proteins. At the end, the author has compiled 

 a bibliography of more than six hundred titles, all dealing with 

 the literature of the subject. This bibliography is sure to be 

 indispensable to all future investigators in this field. 



The botanist should be interested in this subject because any 

 light that can be thrown on the composition and physiology of 

 the proteins of plants, especially those from seeds, would help 

 to clear up the important phenomena of germination and so forth. 

 Furthermore, the isolation of sharply-defined and characteristic 

 proteins from different plants and especially the fact that plants 

 closely related botanically yield proteins that may be grouped 

 together chemically, all go to show that morphological differences 

 go hand in hand with deep-seated chemical differences, a sup- 

 position that ought to be studied much more closely than in the 

 past. The newer immunity reactions of the blood-serum of 

 animals ought to serve as a very delicate test for the relationship 

 of plant constituents just as it has proved so useful in the study 

 of normal and abnormal substances in the case of man and the 

 animals. 



To the chemist. Dr. Osborne's book should bring the results of 

 an exact chemical study of the proteins, substances whose im- 

 portance in both plants and animals can hardly be overestimated. 

 The complexity and cell associatipns of those substances prevent 

 their isolation in a pure state. Fortunately, however, the vege- 

 table proteins can be prepared in a much greater state of purity 

 than almost any of the proteins of animal origin. The result 

 is that studies made upon proteins from plants are very likely 

 to be productive of great advances in our knowledge of the 

 structure and properties of proteins in general. The constancy 

 of the composition and properties of certain of the plant proteins 

 are so great as to lead one to think that definite chemical indi- 

 viduals are being studied. This is a reassuring thought to a 

 chemist working upon proteins who, too often, is afloat in un- 



