HE VIS ION OF THE GENUS NAJAS, 436 



165. Young male iiower. x 70. 



166. Female dower witli scale. x 30. 



167. Seed, x 20. 



Najas Leichhardtii. (Figs. 168 to 171.) 



168. Leaf-sheath: side view, x 20. 



169. Small portion of leaf-blade, x 20. 



170. Apex of male flower, showing neck of slieath {s), und tip of perianth [p). x 24. 



171. Female flower. x24. 



Nujas australis. (Figs. 172 to 176.) 



172. Upper part of leaf-sheath opened. x 6. 



173. Portion of blade. x 20. 



174. Female Hower. x 20. 



175. Fruit, x 18. 



176. Markings on surface of testa. Mnch enlarged. 



Najas set area. (Figs. 177 to 182.) 



177. Leaf-shcath. x 25. 



178. Intravagiual scale, x 30? 



179. Apexofleafj. x 50. 



180. Portion of leaf-margin, showing two spine-teeth. Much enlarged. 



181. Female flower, x 30. 



182. Seed. x 15. 



a Najas horrida. (Figs. 183 to 191.) 



183. Base of blade with opened sheath, x 5. (Central African specimen collected by Schweiufurth.) 



184. Side view of leaf-sheath, from same plant as fig. 183. X 5. 



185. „ „ from plant collected at Mozambique by Schlechter. x 10. 



186. Marginal leaf -tooth from Tanganyikan specimen (Hore). Much enlarged. 



187. Transverse section of stem of same specimen as fig. 186. x 50. Showing (1) epidermal layer, 



(2j six to seven layers of starch-containing cortical cells with large intercellular spaces, and (3) 

 central stele with axial air-canal. The structure of the stele is imperfectly shown in so small a 

 sketch ; it is by no means homogeneous, but consists of larger cells, more or less rounded in 

 section, and irregular strands and masses of much smaller very thin- walled cells, multangular in 

 section, and rich in proteid or protoplasm (presumably bast-tissue). 



188. Young male flower, x 23. 



189. Transverse section of mature male flower, showing cruciform arrangement of the four anther-cells. 



Much enlarged. 



190. Female flower, after fertilization. x 20. 



191. Seed, x 12. 



Najas graminea. (I'i^is. 192 to 202.) 



192. One side of opened leaf-sheath. X 12. 



193. Portion of leaf-margin of specimen from Philippines {Moselcy). Much enlarged. 



194. „ ,, „ Abyssinia [Steudner). Much enlarged. 



195. „ „ „ (jwalior (iV/an>i*). Much enlarged. 



SECOND SERIES. — BOTANY, VOL. V. 3 U 



