The Elements of BotanyUniversity Press, 1896 - 235 עמודים |
מהדורות אחרות - הצג הכל
מונחים וביטויים נפוצים
antheridium antherozoids anthers archegonium axis bean branch bulb buttercup calyx cambium carpels cavity cell-sap cell-wall cellulose central cylinder centre chapter character cherry colour consists containing cork corolla cortex cotyledons developed divided dog-daisy egg-cell elongated embryo embryo-sac endodermis epidermis Examine fact fern fertilisation fibres filaments floral diagram florets flower fruit germinating glycerine green growing point growth Helianthus high power known layer leaf leaves longitudinal section low power Maout and Decaisne medullary rays micropyle Mucor ovary ovule parenchyma pericycle petals phloem pith plant plantain plumule pollen pollen-grain potato prothallus protoplasm Pteris radicle Ranunculus receptacle reproduction rhizome RHIZOME OF Pteris root-cap sclerenchyma seed seed-coat seedling seen sepals shewing showing shown in fig sieve-tubes sketch spiral Spirogyra sporangia sporangium spores sporophyte stalk stamens starch grains stem stigma structure style sunflower surface tissue tracheids transverse section tree tube tuber vascular bundles vertical vessels walls wood xylem yeast young
קטעים בולטים
עמוד xvi - I conceive it is a fine study, and worthy a gentleman, to be a good botanic, that so he may know the nature of all herbs and plants...
עמוד 208 - Oak twig of the current year. Mount in glycerine and examine with a low power. Show on your sketch a. epidermis ; b. cortex ; c. vascular bundles forming an irregular ring ; d. pith ; e. medullary rays. Sketch a single bundle, shewing its xylem, phloem and cambium, and compare your sketch with that of a bundle in the Sunflower, noting that in the Oak there is a large amount of thick-walled wood fibre. ii. Examine a transverse section of the stem of an Oak seedling, and...
עמוד i - German botanist, these cells enable the plant to perceive the difference between light and dark, and set up a stimulus which results in the movement of the leaf into such a position that it can obtain the maximum amount of light ; or it may be, as Mr. Wager is inclined to think, that these cells serve for the more efficient illumination of the green grains within the leaf upon which the effective food-supply of the plant depends. Possibly both play some part in aiding the leaf to perform its work...
עמוד 2 - In a wooden match are many thousands of cells of which the walls are cellulose1. If such a piece of wood is dipped in strong sulphuric acid or is charred by fire a mass of charcoal is the result. This fact proves that cellulose contains carbon, and as a matter of fact carbon makes up nearly half the weight of this substance. Cellulose also contains hydrogen and oxygen in the proportion in which they exist in water, its formula being C6Hi005.
עמוד i - In many cases these lens-cells may be compared with the corneal facets of an insect's eye, so far as their general appearance and power of causing a convergence of light are concerned. In addition to ordinary methods of photography, it has been found possible to obtain photographs of simple patterns In colors by means of autochrome plates.