NUTRITION.— PALEONTOLOGY. 305 



teins have, as yet, been found only in tissues that are biologically 

 nearly related. Thus guinea-pigs sensitized with gliadin from wheat, 

 or from rye, give strong anaphylactic reactions with hordein from 

 barley, but these are not as strong as the reactions obtained with the 

 homologous protein. Similar results are obtained if the sensitizing 

 protein is hordein and the protein used for the second injection is 

 gliadin. These results are of interest because gliadin and hordein, 

 while similar in their chemical constitution, are nevertheless distinctly 

 different proteins. Saturation experiments showed that guinea-pigs 

 when sensitized with either gliadin or hordein, and then saturated 

 with the heterologous protein, still react strongly when injected with 

 the homologous protein. Gliadin and glutenin react anaphylactic- 

 ally with one another, although they are proteins of distinctly dif- 

 ferent types. The conclusion appears justified that these chemically 

 different proteins contain common reactive groups. Guinea-pigs 

 sensitized with glutenin do not react anaphylactically with hordein, 

 thus showing that the reaction between gliadin and glutenin is not 

 caused by an incomplete separation of these latter proteins, but by 

 reactive groups common to gliadin and glutenin, but absent from 

 hordein. These experiments demonstrate that the "group reactions" 

 characteristic of biological reactions between closely related species, 

 which usually have been interpreted as indicating the presence in 

 related organisms of identical as well as distinct proteins, can really 

 be exhibited by single isolated proteins from related organisms. In 

 other words, biological relationship and chemical relationship seem to 

 be much the same. 



PALEONTOLOGY. 



Case, E. C. University of Michigan, Ann Arbor, Michigan. Grant No. 

 836, allotted December 13, 1912. Completion of the work on the 

 Permian vertebrate fauna of North America. (For previous reports 

 see Year Books Nos. 2, 4, 8-11.) $2,000 



Mr. Case has continued work upon the Permo-Carboniferous fauna 

 of North America during the year. Especial attention has been paid 

 to the geographical distribution of the fauna, its origin, evolution, and 

 extinction — its relation to foreign forms and its migrations. The 

 location of the various beds in which the fauna has been found has 

 been studied and an attempt made to determine the area and posi- 

 tion of the deposits in Permo-Carboniferous time and the age of the 

 beds. Considerable work has been done upon the structure and the 

 material of the beds in an attempt to determine the climatic and 

 other factors which governed the evolution of the fauna. During 

 the summer of 1913 Mr. Case extended his field work into Arizona 

 and revisited the Texas localities. 



