| United States. Congress. House - United States - 586 pages
...At one period of the year they are oviparous; at another, viviparous; and what is most remarkable, the sexual intercourse of one original pair serves...proceed from the female for a whole succeeding year, before the spermatic virtue of the ancestral coitus is exhausted. It has been proved that, in five... | |
| William Kirby, William Spence - Entomology - 1822 - 618 pages
...greatest enemies of the vegetable world, and like them arc sometimes so numerous as to darken the air*. The multiplication of these little creatures is infinite...fecundity, which no other insects possess : at one tune of the year they are viviparous, at another oviparous; and, what is most remarkable and without... | |
| Gill's scientific, technological and microscopic repository - 1829 - 424 pages
...they are viviparous, at another oviparous ; what is most remarkable and without parallel, the sexiufl intercourse of one original pair serves for all the...proceed from the female for a whole succeeding year ! Reamur has proved that, in five generations, an aphis may be the progenitor of 5,904,900,000 descendants;... | |
| Cuthbert William Johnson - Agricultural chemistry - 1844 - 1210 pages
...insect causes is not wonderful when we reflect on the astonishing fecundity of all the aphides family. The sexual intercourse of one original pair serves...all the generations which proceed from the female in the succeeding year; and Reaumur informs us, that, in five generalions, one aphis may be the progenitor... | |
| Henry Stephens - 1844 - 748 pages
...are the greatest enemies of the vegetable world, and like them are so numerous as to darken the air. The multiplication of these little creatures is infinite...incredible. Providence has endued them with privileges for promoting fecundity, which no other insects possess : at one time of the year they are viviparous,... | |
| Medicine - 1848 - 910 pages
...greatest enemies of the vegetable world, and like them are sometimes so numerous as to darken the- air. The multiplication of these little creatures is infinite...pair serves for all the generations which proceed (mm the female for a whole succeeding year. Reaumur has proved that in five generations one Aphis may... | |
| Richard Owen - Human reproduction - 1849 - 92 pages
...larvipnrous Aphides, Ammen, or ' wetnurses f'; says the species is propagated by ' alternate gene• " The multiplication of these little creatures is infinite...and almost incredible. Providence has endued them wild privileges promoting fecundity, which no other insects possess : at one time of the year they... | |
| Homeopathy - 1855 - 766 pages
...hundred thousand descendants ; and it is supposed that in one year there may be twenty generations ; and what is most remarkable and without parallel,...proceed from the female for a whole succeeding year."* Here is a problem, which, ably and correctly worked out, will outvie Dr. Simpson's abstruse and rather... | |
| Henry Stephens - Agriculture - 1852 - 828 pages
...the greatest enemies of the vegetable world, and, like them, are so numerous as to darken the air. The multiplication of these little creatures is infinite,...incredible. Providence has endued them with privileges for promoting fecundity, which no other insects possess : at one time of the year they are viviparous,... | |
| Henry Stephens - Agriculture - 1853 - 854 pages
...the greatest enemies of the vegetable world, and, like them, are so numerous as to darken the air. The multiplication of these little creatures is infinite,...incredible. Providence has endued them with privileges for promoting fecundity, which no other insects possess : at one time of the year they are viviparous,... | |
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