EXPLANATION OF THE PLATES. XV 



PLATE V. 



Fig. 1. Longitudinal section of Agaricus procerus: a. the stem; b. 

 the lax pith ; c. a fragment of the pileus. (p. 293). 



2. Portion of the stem of Ptychosperma gracilis (from Mirbel): 



a. exterior ligneous and vascular bundles; I. interior lig- 

 neous and vascular bundles, (p. 299). 



3. A. A transverse slice of the stem of Trigridia pavonia, of 



the natural size : B. a portion of the same magnified, (p. 

 294). 



4. A longitudinal section of the scape of Typha latifolia. (p. 



294). 



6. A. A transverse slice of the stem of Allium molly. B. 

 a portion of the above slice magnified ; a. the cutis ; b. 

 vascular bundles : C. a magnified vertical section of the 

 above: a. the cutis; b. vascular cords ; c. c. cellular mat- 

 ter: D. the natural size of the part, of which C. is one 

 half, highly magnified. 



6. Portion of a transverse slice of the stem of Juncus conglo- 



meratus, highly magnified ; a. the pith ; b. the cortex ; c. d. 

 bundles of spiral vessels ; e. air cells dividing the vascular 

 cords ; /. bundles of proper vessels, forming the striae on 

 the surface of the stem : g. g. lacunae between the cortex 

 and the pith. 



7. Section of a transverse slice of the stem of Hippuris vulgaris, 



highly magnified: a. the exterior or cellular part; b. the 

 centre, which is vascular; c. an uncoiled vessel. 



8. A. A transverse slice of the culm of Triticum astivum, 



slightly magnified. B. a vertical section of one side of 

 the tube, highly magnified: a. longitudinal cells, under the 

 epidermis; b. the pith; c. a spiral vessel. C. a transverse 

 section of a portion of the above slice, highly magnified : 

 a. the cutis; b.c. vascular bundles, (p. 301). 



9. Vertical section of a portion of the stem of Tradescantia 



virffinica: a. a. a. a. a. a. a. vascular cords; b. b. fragments of 

 the base of the leaf, which in this plant is sheathing. 

 b4 



