A STUDY IN PLANT VARIATION 



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cent when young. This pubescence is due to hyaline, unicellular, 

 epidermal hairs. The stipules are Unear, lobed, pubescent, glandular- 

 serrate and very early deciduous. The leaves are more or less rounded at 

 the base, acute at the apex, finely and sharply serrate with glandular 

 tipped teeth when young. At the junction of the lamina and petiole 

 are two rather large conspicuous glands. In regard to leaf variation, 

 in lamina and petiole considerable diversity exists, and the main types 

 that are associated with the varying colors of fruits are set forth in the 

 subjoined table. 



The above measurements are the average of ten selected leaves. 

 Small Blue (1) is var. coerulea parva from Cape May Point; (2) var. 

 praecox from Hainesport, N. J. The leaves are puberulous on the up- 

 per surface along the midrib in all varieties, while in the blues and in 

 the yellows the pubescence seems to exist along the main veins as 

 well. In the reds and in the purples the upper surface of the blade 

 appears glabrous except along the midrib. On the lower epidermis the 

 pubescence is located along the midrib and in the axils of the main 

 veins. The small inland blue var. praecox appears as pubescent on the 

 lower surface as on the upper, while the small yellow var. lutea parva is 

 pubescent along both veins and cross veins, but not as pubescent on the 

 lower as on the upper surface. These details are set forth in compara- 

 tive order in the table, on the following page. 



Small Blue (1) var. coerulea parva; (2) var. praecox. 

 The pubescence of the small yellow is more dense on the upper epi- 

 dermis, and appears to be very characteristic of it. Stomata occur only 

 on the lower surface in island-like formations. Sometimes these islands 

 are irregular and indistinct, i.e., broken up into a number of smaller 

 ones, which makes it rather difficult to get an accurate account of the 

 number of stomata in an island area. The midrib, veins and nerves 



