FAGACEAE. 33 



Blakeslee & Jarvis, 338-9, 444, pi.; Cobb, Proc. Amer. Phil. 

 Soc., 54:174, pi. 6; Schneider, f. 155. Q. Muehlenbergii. 

 Blakeslee & Jarvis, 338-9, 440, pl.;| Brendel, pi. 2; Hitchcock 

 (3), 139, f. 111-112; Otis, 106. Q. myrtifolia. Trelease (3), 

 pi. 12. Q. nigra (Q. aquatlca) . Trelease (3), pi. 12. Q. palus- 

 trls. Blakeslee & Jarvis, 338-9, 448, pi.; Hitchcock (1), 5; 

 Otis, 110; Trelease (3), pi. 12. Q. Phellos. Schneider, f. 157; 

 Trelease (3), pi. 12. Q. prinoides. Blakeslee & Jarvis, 338-9, 

 442, pi.; Hitchcock (1), 5, (3), 19. Q. prinoides rufescens. 

 Blakeslee & Jarvis, 442. Q. pubescens. Bosemann, 71; Will- 

 komm, 4, 23, f. 22. Q. pumila. Trelease (3), pi. 12. Q. Ro- 

 ~bur (Q. pedunculata) . Bosemann, 71; Pant, 11, f. 1; Schnei- 

 der, f. 16, 157; Ward, 1:47, f. 30, 418, f. 59, 217, f. Ill: The 

 Oak, 72, f. 19; Willkomm, 7, 22, f. 20; Zuccarini, 6, pi. 3. Q. 

 ru~bra. Blakeslee & Jarvis, 338-9, 446, pi.; Brendel, pi. 2; 

 Hitchcock (1), 5, (3), 19; Otis, 108; Schneider, f. 55, 154; 

 Trelease (3), pi. 11. Q. Schneckii. Trelease (3), pi. 11. Q. 

 serrata and var. variabilis. Shirasawa, 258, pi. 7. Q. sessili- 

 flora (held by many as true Q. Robur). Bosemann, 71; Fant, 

 11; Schneider, f. 157; Willkomm, 23, f. 21: Q. stellata. Blakes- 

 lee & Jarvis, 338-9, 434, pi.; Cobb, Proc. Amer. Phil. Soc., 54: 

 174, pi. 4; Hitchcock (1), 6. Q. texana. Trelease (3), pi. 11. 

 Q. velutina (often referred to as Q. coccinea; Q. tinctoria). 

 Blakeslee & Jarvis, 338-9, 452, pi.; Brendel, pi. 2; Hitchcock 

 (1), 5, (3), 19, (4), 138, f. 113-115; Otis, 116; Trelease (3), pi. 

 10. Q. Wislizeni. Trelease (3), pi. 13. 



Oaks, like poplars, willows and some other trees, cast off 

 many of their twigs by imperfect abscission in the autumn, 

 a normal and regular process each year on old trees, as 

 Areschoug has pointed out in his Biologie der Holzgewachse. 

 This self-pruning forms the subject of a communication in 

 1865 to the Botanische Zeitung by Rose. Engelmann (Botani- 

 cal Works, 391) has indicated the differences in vernation 

 shown by species of Quercus, and Diez published a compara- 

 tive study of the subject in Flora for 1887. 



