XVI BRITISH FLOWERING PLANTS 



I-IG. PAOE 



272-292. Quercus pedunculata : pairs of stipules forming the scales 



of the winter bud, sketched in the first week of May 373 



293. Young female flower of Oak with involucre of scales 374 



294. The same, cut lengthwise 374 



295. Cone-scale of Birch . . . .375 



296. Diagram of a three-flowered group from the female catkin of 



Birch (after Eichler) . .375 



297. Pair of fruits of Hornbeam . . . .376 



298. Diagram of a pair of female flowers of Hornbeam (after 



Eichler) . . 376 



299. Pair of fruits of Hazel, each in its involucre . .377 



300. Plan of arrangement of a male flower of Hazel (after 



Eichler) . . 377 



301. 302. Female and male flowers of Hazel . 377 



303. Populus nigra, : terminal winter bud, showing a pair of 



persistent stipules belonging to a leaf of last season 379 



304. Black Poplar shoot . 381 



305. Pinus sylvestris ; fragment of terminal bud representing 



seven tiers of scales of the winter bud . 384 



306. Pinus sylvestris : a detached scale-base . 384 



307. Do. analysis of terminal bud 385 



308. Do. apex of branch . . 385 



309. Picea excelsa : apical and two lateral buds showing pedestals 



of leaves after the green portion has been removed . 387 



310-315. Picea excelsa: normal and perfect leaf, and successive 



modifications to form scales . . . .387 



316-318. Picea excelsa: inner scales after they have elongated 



about the middle of April . . .387 



319. Diagrammatic section of Arum . . . 390 



320. Flower of Lemna trisulca (after Le Maout and Decaisne) . 392 

 321-323. Position of the chlorophyll granules in the cells of the 



frond of Lemna trisulca in darkness, in diffused light, 

 and in sunlight (after Stahl) .... 393 

 324-327. Potamogeton nutans : palisade cell of leaf in dift'used light 



and in sunshine, with sections of same (after Stahl) 395 



328. Diagrammatic section of Orchid flower (after Darwin) 400 



329. Orchis mascula (after Bentham) . . . 401 



330. Orchis mascula : side view of flower, with sepals and petals 



cut off except the lip, of which the near half is cut away, 

 showing relation of poUinia and nectary (after Darwin) . 402 



331. Orchis mascula: front view of flower, with sepals and petals 



removed except the lip (after Darwin) . .402 



