 | Charles Darwin - 1861 - 470 páginas
...20 other heads protected from bees produced not one ; again, 100 heads of red clover (T. pratense) produced 2700 seeds, but the same number of protected...red clover, as other bees cannot reach the nectar. Hence I have very little doubt, that if the whole fanus of humble-bees became extinct or very rare... | |
 | 1867 - 378 páginas
...heads of red clover (trifolium pretense) produced 2,700 seeds, but the some number of protected hends produced not a single seed. Humble-bees alone visit...cannot reach the nectar. It has been suggested that mothsmay serve to fertilize the clovers ; bat I doubt this in the case of the red clover, from' their... | |
 | Charles Darwin - 1864 - 472 páginas
...20 other heads protected from bees produced not one ; again, 100 heads of red clover (T. pratense) produced 2700 seeds, but the same number of protected...red clover, as other bees cannot reach the nectar. Hence I have very little doubt, that if the whole genus of humble-bees became extinct or very rare... | |
 | Charles Darwin - 1870 - 468 páginas
...from bees produced not one ; again, 100 heads of red clover (T. pratense) produced 2700 seeds, out the same number of protected heads produced not a...red clover, as other bees cannot reach the nectar. Hence I Jiave very little doubt, that if the whole genus of humble-bees became extinct or very rare... | |
 | John Tillotson - 1870 - 1154 páginas
...were flowers of that sort ? or if the flowers were first, how did they multiply without the insects ? Humblebees alone visit red clover, as other bees cannot reach the nectar ; and they are almost indispensable to the fertilisation of the heartsease, a flower not visited by... | |
 | 1874 - 586 páginas
...almost indispensable to the fertilization of th.e heart's ease, for these Bees do not visit this flower. HumbleBees alone visit red clover as other Bees cannot reach the nectar. In a word — no Bees, no seed ; no seed, no increase of the flower. The more visits from Bees, the... | |
 | Dr. Schmidt (Eduard Oskar), Oscar Schmidt - 1875 - 372 páginas
...protected from bees, produced not one. Again, 100 heads of red clover (T. pratense) produced 2,700 seeds, but the same number of protected heads produced...reach the nectar. It has been suggested that moths may fertilize the clovers ; but I doubt whether they could do so in the case of the red clover, from their... | |
 | Charles Darwin - 1875 - 504 páginas
...heads protected from bees produced not one. Again, ICO heads of red clover (T. pretense) produced 2,700 seeds, but the same number of protected heads produced...reach the nectar. It has been suggested that moths may fertilise the clovers ; but I doubt whether they could do so in the case of the red clover, from their... | |
 | Dr. Schmidt (Eduard Oskar), Oscar Schmidt - 1875 - 362 páginas
...protected from bees, produced not one. Again, 100 heads of red clover (T. pratense) produced 2,700 seeds, but the same number of protected heads produced...reach the nectar. It has been suggested that moths may fertilize the clovers ; but I doubt whether they could do so in the case of the red clover, from their... | |
 | William Swinton, George Rhett Cathcart - 1880 - 364 páginas
...clover yielded 2290 seeds, but twenty other heads protected from bees produced not one. Again, a hundrea heads of red clover produced 2700 seeds, but the same...number of protected heads produced not a single seed. 4. Humble-bees alone visit red clover, as other bees cannot reach the nectar. Hence I have very little... | |
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Hence we may infer as highly probable that, if the whole genus of humblebees became extinct or very rare in England, the heartsease and red clover... 
