kempton: ancestry of maize 3 



specimens seven species appear to be new out of thirty-three 

 which are specifically identifiable, or nearly 20 per cent. 



The ensemble of the collection points to climatic conditions 

 similar to those prevailing at present in the region, while the 

 earliest Nome bed indicates decidedly warmer water. It is 

 probable that this Pribilof fauna conformed to more rigorous 

 conditions prior to the glacial epoch. 



The St. George collection as a whole has only seven species 

 identical • with those found at Black Bluff, St. Paul Island, 

 which latter fauna is doubtless Pleistocene. With the Pliocene 

 second elevated beach fauna at Nome one-third of the St. George 

 collection is identical, but in this third the characteristic warmer 

 water species are not represented. So I conclude that the 

 material obtained by Mr. Hanna represents a period later than 

 the Nome second beach and earlier than that of the Black Bluflf 

 fauna. A list of the species is given in table i. The type 

 specimens are preserved in the U. S. National Museum. 



BOTANY. — The ancestry of maize. J. H. Kkmpton, Bureau of 

 Plant Industry. (Communicated by William R. Maxon.) 



In a recent article entitled The evohiiion of maize, Weather- 

 wax^ raises again the issue of the origin of the genus Zea. He 

 reviews the literature, summarizes the descriptions, and presents 

 in a new light many of the morphological differences and 

 similarities of Zea mays and the related plants, Euchlaena 

 luxurians and Tripsacum dactyloides. Students of these genera 

 will welcome the bringing together of these descriptions, accom- 

 panied as they are by excellent illustrations. Since the article 

 aims at a comprehensive evaluation of the relationship of these 

 genera, it is perhaps unfortunate that much of the "gross 

 morphology" has been disregarded, with a consequent over- 

 emphasis of the organological features. There are, moreover, 

 a few misstatements, and some of the views of previous workers 

 seem to have been misinterpreted. It is hoped that a discussion 

 of these points will contribute to a better understanding of the 

 subject. 



' Weatherwax, Paul. The evolution of maize. Bull. Torrey Club 45: 309-342 

 1918. 



