42 BOTANICAL GAZETTE [JANUARY 
in a portion of the formation where the shrubby layer was entirely 
lacking, is shown in table VIII. 
Fig. 6 reveals the facts in an even more striking way. Before 
considering this graph of the age distribution, it should be stated 
that the five inch circumference classes are arbitrarily chosen. 
Each class represents approximately fifteen years. If actual age 
determinations were at hand, it would be desirable to use a one 
year class, thus more exactly recording the facts. It is thus 
os 2&8 Classes 
RST ZF Circun 
Se ie Ht 
Ron aA A al 
° a Frequency 
— Pinus resinosa 
re) 
aanw Quercus rubra 
© Acer rubrum 
OrPMWUANAN OO 
Fic. 6.—Age distribution of facies, Upper Pines, stations 6 and 7. 
realized that the conclusions drawn from the graph are perhaps 
more valuable as a suggestion of a valid method of analysis than 
as a scientific representation of the actual conditions. It will 
be noted that the ratios of the three principal species of the 
facies (table VIII) are in almost perfect agreement with the ratios 
of frequency percentages as shown in table VII. It would appear 
that the transect analyzed is fairly representative of the formation. 
Fig. 6 shows that the great mass of the individuals of the yellow 
pine lie between circumferences of 10 to 55 inches, which represents 
an approximate age range of 30-175 years. There are a few isolated 
