46 SPECIFICITY OF THE BLOOD OF VERTEBRATES 



Vicia, and Phaseolus present marked differences in their proteins, whereas the proteins 

 of the species of each genus are very much alike. The proteins of Lupinus luteus and 

 of Lupinus angustifolia differ slightly, but in their physical properties are clearly dis- 

 tinguished from any of the other seed proteins. Although similar proteins are obtained 

 from the horse-bean, lentil, pea, and vetch, these are distinctly different from the pro- 

 teins obtained from other leguminous seeds. These seeds are not alike, however, in the 

 proportion of their several proteins. The chief protein of Phaseolus vulgaris appears to 

 be identical with that of Phaseolus radialus, but the small amount of other protein was 

 found to be different in properties and composition in each of these seeds. 



The cow -pea (Vigna) and soy-bean (Glycine) contain distinctly different proteins 

 which, however, are similar to but different from those of Vicia. The globulins of the 

 seeds of Corylus and Juglans are much alike, but not identical, while those from Jug- 

 lans regia, nigra, and cinerea, so far as they have been compared, show no differences. 

 The proteins of other seeds show marked differences, but the botanical relations of 

 these seeds are not such as to permit of further discussion of this subject. 



As stated in the Introduction, it was our intention to embody in this 

 memoir a study of the crystallography of certain classes of plant proteins, 

 especially those of seeds and nuts. Owing to the reasons stated, we had the 

 opportunity of examining only an extremely limited number of these sub- 

 stances, but from the peculiarities noted we believe that sufficient differences 

 will be found to enable the differentiation of one from another, and hence 

 to be of generic specificity. 



THE ZOOPRECIPITINS AND PHYTOPRECIPITINS AND IMMUNE SERA IN 



RELATION TO GENERA. 



Another important means of biological differentiation has been brought 

 to light during recent years in the discovery of the zooprecipitins and phy- 

 toprecipitins, and by various facts pertaining to the chemistry of immune 

 sera, etc. The results of the investigations along these lines point clearly 

 to the specificity of certain as yet obscure but closely related proteins to 

 certain constituents of different genera. Agglutinins and hemolysins exhibit 

 definite specificities. Reference will be found elsewhere to specificities that 

 are shown by hemolysins. 



THE SPECIFICITY OF THE BLOOD IN ZOOLOGICAL DIFFERENTIATION AS 

 SHOWN BY THE PHENOMENA OF COAGULATION. 



The differences in the rapidity of the coagulation of the bloods of 

 different genera show definite generic peculiarities. Thackrah (Ellen- 

 burger's Physiologic der Haussaugethiere, 1890, 165) found that coagu- 

 lation begins in the blood of the sheep, pig, and rabbit in from 0.5 to 1.5 

 minutes; in the chicken in 1.5 minutes; in the dog in 1 to 3 minutes; in 

 the bullock in 5 to 12 minutes; and in the horse in 5 to 13 minutes. These 

 records have confirmation in those of Delafond (ibid..), who found the 

 following order of coagulability: Dog and sheep in 5 to 8 minutes; pig in 

 12 to 16 minutes; horse in 15 to 18 minutes; and bullock in from 25 to 30 

 minutes. 



The bloods of cold-blooded animals coagulate less rapidly than those 

 of warm-blooded animals. There are other differences, such as the density 

 of the contracted clot and the size of the clot. Thus, the contracted clot of 



