i88 9 .] 



BOTANICAL GAZETTE. 



IO7 



sylvestris than in the adult leaf. It may, therefore, be fairly 

 regarded as showing the beginnings of a series of mechan- 

 isms and systems which in Pinus sylvestris have reached 

 a high development. In Taxodium we find these variant in 

 orm, in position, in development; in Pinus, constant in all 

 these particulars. 



Purdue University, Lafayette, Ind. 



Explanation op Plate XI.-The magnification figures were upon 

 the original drawings. These having been reduced one-half, the magni- 

 fication figures must be correspondingly reduced. 



Fig. 1. A. Single leaf of T. distichum in position. B. Leafy branch - 

 let, with its crowded, 2-ranked, linear leaves. 



Fig. 2. Cross section of leaf of T. distichum, showing the three re- 

 gions of which the leaf is composed, distribution of strengthening cells, 

 and position of resin duct. 



Figs. 3, 4, and 5. Same, more highly magnified, showing also distri- 

 bution of stomata. The three figures, as can be readily seen, are parts of 

 the same section. 



Fig. 6. Surface slice of T. distichum, showing irregular outlines of 

 epidermal cells and depressed position of stomata. 



Fig. 7. Section of stoma of T. distichum, showing depressed position, 

 oval guard cells with heavily thickened outer walls, and large respiratory 



Fig. 8. (Letter press, p. 80) Section of stoma of Pinus sylvestris. 

 Fig. 9. Longitudinal section, leaf of T. distichum, showing formation 

 a P® x of leaf by a continuation of epidermal cells of inner surface and 

 modification of adjacent cells. 



Fig. 10. Median vertical longitudinal section, leaf of T. distichum. s, 

 superior surface; i, inferior surface; si, strengthening cells ; r, resin duct. 



*ig. 11. Resin duct of T. distichum, showing imperfect differentia- 

 ion from surrounding tissues and irregular thin-walled secretory cells. 



Fig. 12. Resin ducts.of Pinus sylvestris. 

 . Fig. 13. Transverse section of foliage leaf of Pinus sylvestris, show- 



mg the three leaf regions, distribution of strengthening cells and position 

 of resin ducts. 



BEIEFER ARTICLES. 



A modification of the versatile anther.— In the genus Ljjium, for ex- 



^ niple, it is a well-known fact that the anthers are at first erect, but as 



^ ey mature the true versatile character becomes evident. An inspec- 



jon of a young anther shows that the upper portion of the filament is 



aiender. and inaprt^i m- u a ]A ;« *»«»;*» u^ m ^„ *u„ * — i~u„, „* »*.. 



