434 DK. A. B. EENDLE — SYSTEMATIC 



135. Marginal tooth of blade. Highly magnified. 



136. Back view of portion of blade, showing dorsal teeth. Enlarged. 



137 Portion of transverse section of stem, showing epidermis, starch-containing cortex with large inter- 

 cellular spaces, and central stele. The last consists of small-celled tissue with a few larger cells 

 at irregular intervals, surrounding a central intercellular space, x 80. 



138. Male flower. X 25. 



Najas foveolata. (Figs. 139 to 144.) 



139. One-half of an opened leaf -sheath. x 10. 



140. Apex of leaf, x 10. 



141. Young male flower in position, with leaf-bases thrust aside, x 12. 



142. Male flower after anther-dehiscence (var. minor) . x 12. 



143. Seed, x 18. 



144. Transverse section of fragment of testa. Highly magnified. Showing the three layers; an outer 



one of large thin-walled cells with delicate spiral thickenings, a median layer of very thick-walled 

 pitted cells, and an inner layer of tangentially compressed, moderately thickened cells. 



Plate XLII. 



Najas falciculata. (Figs. 145 to 151.) 



145. Leaf-sheath opened, with base of blade, x 20. 



146. Intravaginal scale, x 30. 



147. Tip of leaf, x 40. 



148. Marginal tooth of blade. Highly magnified. 



149. Transverse section of stem. Highly magnified. An inner row of small cells of the stele 



surrounding the central space has been omitted, x 70. (From a specimen collected by Martens 

 at Manila.) 



150. Transverse section of leaf, x 70. (From same specimen as fig. 149.) 



151. Seed, x 20. 



Najas brevistyla. (Figs. 152 to 157.) 



152. Portion of leaf -blade. X 40. 



153. Intravaginal scale, x 20. 



154. Male flower, x 35. 



155. Pollen-grains. Highly magnified. 



156. Female flower, x 35. 



157. Seed, x 30. 



Najas tenuifolia. (Figs. 158 to 162.) 



158. One side of leaf-sheath, x 30. 



159. Small portion of leaf-margin. Much enlarged. Showing tooth and thick hypodermal supporting 



fibre. 



160. Male flower, x 9. 



161. Female flower, x 30. 



162. Seed, x 17. The conspicuous narrowing at the base shown in the figure is unusual. 



Najas Browniana. (Figs. 163 to 167.) 



163. One side of leaf-sheath, x 24. 



164. Small portion of leaf -margin, showing projecting spine-cell. Much enlarged. 



