. La botanique pour les jeunes et les écoles communes. Comment les plantes poussent, une simple introduction à la botanique structurels. Avec une flore populaire, ou un arrangement et description des plantes communes, à la fois sauvage et cultivée. La botanique, la botanique. Comment les plantes sont TROPAGATED.. Fig. 189, pistil de le mille-pertuis, simplement composé de trois simples, avec leurs ovaires complètement united, tandis que leurs styles minces sont séparés. Fig. 190, même des bandes arbustives le mille-pertuis, comme la dernière, mais witii les trois styles aussi grandi ensemble en un seul, le peu de stigmates que sepa- taux ; mais comme il devient plus âgé style tliis ge

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. Botany for young people and common schools. How plants grow, a simple introduction to structural botany. With a popular flora, or an arrangement and description of common plants, both wild and cultivated. Botany; Botany. HOW PLANTS ARE TROPAGATED.. Fig. 189, pistil of Common St. John's-wort, plainly composed of three simple ones, with their ovaries completely united, while their slender styles are separate. Fig. 190, same of Shrubby St. John's-wort, like the last, but witii the three styles also grown together into one, the little stigmas only sepa- rate ; but as it gets older tliis style generally splits down into three, and when the pod is ripe it also splits into three, plainly showing that this compound pistil consists of three united into one. On turning now to Fig. 8 and Fig. 10 to 12 on the same page, it will be seen that the pistil in Morning-Glory and in Lily is a compound one, made of three united even to their stigmas. This is shown externally, by the stigma being some- what three-lobed in both. And it becomes perfectly evident on cutting t1ie ovary in two, bringing to view the three cells (Fig. 12, as in Fig. 189, 190), each an- swering to one simple ovary. 216. So compound ovaries generally have as many cells as there are simple jjistils or pistil-leaves in their composition ; and have the placentas (199) bearing the seeds all joined in the centre : that is, the placentas or compound placenta in the axis. But sometimes the partitions or divisions between the cells vanish, as in Pinks : then the compound pistil is only one-celled. And sometimes there never were any partitions; but the pistil was formed of two, three, or more open [tistil-leaves grown together from the first by their edges, just as petals join to make a monopetalous corolla. Then the ovules or seeds, or the placentas that bear them, are parietal, that is, are borne on ihe parietes or wall of the ovary. Fig. 191 is the lower part of a compound ovary, with tliree joa- rietalplace?itas or

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• bookcentury1800
• bookdecade1850
• booksubjectbotany
• bookyear1858