205 



Last year Mr. E. Bethel found a white-flowered form (albi- 

 €rum, nov.) below the glacier. 



The continued observation of variations in plants, in different 

 parts of the world, brings out the fact that these are (unless 

 environmental) almost always due to the shuffling or loss of 

 genes which are themselves of great antiquity. Thus the com- 

 parative study of minor differences becomes increasingly im- 

 portant for the understanding of the origin of species, as well as 

 for horticulture. With our greatly increased knowledge of the 

 processes of heredity, we can now go into the field and inter- 

 pret our observations in ways formerly impossible, so that the 

 study of variation becomes increasingly fruitful. 



In Europe the minute study and taxonomic treatment of 

 plant-variation has been carried to extremes unknown in this 

 country. The European literature in large part needs rein- 

 terpretation in the light of genetic research, but it affords an in- 

 valuable basis for comparisons. 



PLEISTOCENE PLANTS FROM INDIAN HEAD, 

 MARYLAND. 



By Edward W. Berry 



About a year ago I' received a small collection of plant remains 

 from Mr. Geo. B. Lloyd who collected them at the bottom of a 

 dug well at Indian Head in Charles County, Maryland. The 

 well is in the Talbot formation and is located near the 20-foot 

 contour on the northern edge of the valley of Mattawoman Creek. 



The materials passed through in the digging of the well, as 

 reported by Mr. Lloyd, are as follows: 



Feet 



Yellow clay lo 



Fine yellow sand 12 



Gravel 9 



Blue clay with vivianite 10 



Bluish sandy clay with leaves i}^ 



A considerable flora has previously been recorded from the 

 Pleistocene of Maryland, the interest in the present small col- 

 lection consisting in the clearly indicated changes of level since 



