. Plant studies; an elementary botany. Botany. Fig. 110. A ]ioIk-n grain (spore) from the ]iiiu', wiiicli ilr\-el()])s wings (;rl to assist ill its lianspnrtatiiju by curreuts of air. It is evident that for tlie germination of seeds liglit is not an essential condition, for tliey niay germinate in tlie liglit or ill tlie dtirk ; Init the need of heat, moisture, and oxygen is very a.])]) The amount i>f heat re- quired for germination varies widely witli iliiferent seeds, some germinating at mucli lower temjiera- tures than others. Every kind (if seed, or spore, or egg has a special te
. Plant studies; an elementary botany. Botany. Fig. 110. A ]ioIk-n grain (spore) from the ]iiiu', wiiicli ilr\-el()])s wings (;rl to assist ill its lianspnrtatiiju by curreuts of air. It is evident that for tlie germination of seeds liglit is not an essential condition, for tliey niay germinate in tlie liglit or ill tlie dtirk ; Init the need of heat, moisture, and oxygen is very a.])]) The amount i>f heat re- quired for germination varies widely witli iliiferent seeds, some germinating at mucli lower temjiera- tures than others. Every kind (if seed, or spore, or egg has a special temperature range, lielow which and ahovc which it cannot germinate. The two limits of tlie rtinge may be called the lowest and highest points, but be- tween the two tliere is a best point of temperature for germination. The same genertil fact is true in reference to the moisture supply. 74. Dispersal of reproductive bodies. âAmong tlie most striking external relations, however, tire those con- nected widi the disperstil of sjiores, gajiietes, tind seeds. Spores and see(ls must lie ctirried tiwtiy from the ptu'cnt iihtiit, ttnil separated from eacli other, out of the reach of rivali'y for nutritive materitil ; ;ind gametes must come together and â ., '^ '^ , FLii. 111. .\ piiil ol lireweeii lili^nd to form the eggs. Conspicuous (/â ./);/(i/,i««,i ,,|âniiig and among tlie means of transfer are the ' . \\'liicli arc lraiis|M)rlc(l by following. the Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Coulter, John Merle, 1851-1928. New York, D. Appleton and Company
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Keywords: ., bookcentury1900, bookdecade1900, booksubjectbotany, bookyear1900
