CONTENTS. HI 



Page. 

 XII. — Stamen and Anther 215 



Definition according to text-books — TJie pollen-sac comparable 

 to a sorus — Method of comparison also needed to reach the 

 truth — Anthers of conifera? only indusiate sori — Frond of 

 Porphyra lacininta a rudimentary stamen — Indusia con- 

 sidered as the confluence of hairs — Pinnule of Pteris aquilina 

 by contraction and modification becomes a two-celled anther 

 — Pinbule of Blechnnm Boreale by contraction becomes a 

 one-celled anther — Anthers give rise to tetrads, just as 

 fronds give rise to tetraspores — Glands on petiole of cherry- 

 leaf considered as the fusion of teeth-glands of suppressed 

 leaflets — Teeth-glands correspond to arrested terminal buds 

 —Anther cells and ovular placentas interchangeable — Teeth- 

 glands, pollen grains, and ovules are homologous — Different 

 fonns of two-celled anthers may origiuate from one-celled 

 anthers — Is the quaternary sub-division of mother-cells of 

 any significance, except as a means of identification ? 



XITI. — Carpels, Placentas, Ovules, Bdds, Embryos, and 

 Spores ....-- 243 



Axillary bud — object and genesis — as a free branchlet of the 

 petiole — as connate with the base of the leaf — as connate with 

 the stem — Seaweeds, type forms of existing phsenogams — 

 Asa Gray's definition of bud — Multiple axillary buds, like 

 polyembry in seeds. 



Ovule — Warming's view of the ovule — The nucleus corre- 

 sponds to the kernel of the seed — The gland on the teeth of 

 leaves probably homologous with an ovule — Views of different 

 authors, quoted by Warming — The lobes of Gigartina lan- 

 ceolata, Fucus maryiiiifer (Esper), and Lenormandia mar- 

 ginata, when separated, behave like ovules — Marginal bud of 

 leaf, -and stem or midrib bud, one and the same thing — 

 Parthenogenetic ovules in no way differ from ordinary buds — 

 Henslow's view of the ovule — Fibro-vascular cords not 

 necessary for the evolution of buds — Views of Ray Lankester 

 on bud and ovule — Galton's view of Heredity — Comparison 

 of terminal bud with embryo — Ovule of Hippiiris vulgaris — 

 Anatropus ovule homologous with circinate frond — Ovule, 

 the terminal bud of the vein that feeds it — Integuments of 

 the seed compared to two vaginas of the grass stem — Forms 

 of placentas — Central placenta considered as homologous 

 with the sorus of Trichomanes — The midrib of carpels quite 

 capable of evolving ovules — Dehiscence can occur along 

 margin, midrib, nerve, or vein — Fruit of Lardizahala, a 

 phffinogam, compared with that of Myriodesma, a crypto- 

 gam — Discussion on polyembry — Placenta of phaenogams 

 compared with sorus of ferns — The embryos of Citrus seed 

 homologous with spores in a sporangium. 

 4 p. 172i. A 



