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Updated: June 4, 2025
Now add the value of the wheat, oat and barley straw grown on 1,500 acres, and mostly thrown into the barn-yards, or used as bedding for the stables, and you have one great division of the fertilising department of Chrishall Grange. The amount of these three items cannot be less than 3,000 pounds. Then there is another source of fertilisation nearly as productive and valuable.
To those not acquainted with all that has been ascertained as to the reproduction of lower animals such as insects, crustaceans, and worms, this discovery will appear more astonishing than it really is. We know of many lower animals in which the egg-cells produced by the females do regularly and naturally develop without the intervention of a male and without fertilisation.
With respect to plants, to which on account of Nageli's essay I shall confine myself in the following remarks, it will be admitted that the flowers of the orchids present a multitude of curious structures, which a few years ago would have been considered as mere morphological differences without any special function; but they are now known to be of the highest importance for the fertilisation of the species through the aid of insects, and have probably been gained through natural selection.
He finds that the likelihood of fertilisation increases from the first day of menstruation, reaching the highest point six days later, the fertile period remains almost at the same height till the 12th or 13th day, and then declines gradually until the 22nd day, after which there is absolute sterility.
On the belief that this is a law of nature, we can, I think, understand several large classes of facts, such as the following, which on any other view are inexplicable. Every hybridizer knows how unfavourable exposure to wet is to the fertilisation of a flower, yet what a multitude of flowers have their anthers and stigmas fully exposed to the weather!
All these processes, which outline the typical structure of the vertebrate, take place with astonishing rapidity in the embryo of the Amphioxus; in the afternoon of the first day, or twenty-four hours after fertilisation, the young vertebrate, the typical embryo, is formed; it then has, as a rule, six to eight somites.
The remarkable fact is that from this fertilised ovum or zygote is developed usually an individual of one sex or the other, male or female, other cases being comparatively exceptional, although each act of fertilisation is the union of the two sexes together.
When we remember what an important part the artificial fertilisation of the date palm-tree appears to have played of old not only in the husbandry but in the religion of Mesopotamia, there seems no reason to doubt that the artificial fertilisation of the fig-tree may in like manner have vindicated for itself a place in the solemn ritual of Greek religion.
Thus to give a single instance no man can now be a first-rate botanist unless he be also no mean meteorologist, no mean geologist, and as Mr. Darwin has shown in his extraordinary discoveries about the fertilisation of plants by insects no mean entomologist likewise.
He points out that the use of artificial checks "while preventing fertilisation may also be the means of depriving the female of certain secretions which may exercise a far reaching influence on her economy"; and he concludes, "As a rule we cannot interfere with the normal course of nature without some consequent evil result.
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