Hybridisation and cross fertilisation are also well-known agents in diminishing the number and size of seeds.
Mere variations of form arising from hybridisation or other causes hardly fall within the limits of this work, though it is quite impossible to say where variations end and malformations begin.
The same author often speaks of roses as having been a little hybridised; but it is evident that in very many cases the differences due to variation and to hybridisation can now only be conjecturally distinguished.
Whether all the many recorded cases of striped flowers and fruit are due to previous hybridisation and reversion is by no means clear, for instance with peaches and nectarines, moss-roses, etc.
Nevertheless, the cases above given seem to me to prove that under certain unknown conditions graft-hybridisation can be effected.
Galapagos Archipelago I pushed with the muzzle of my gun hawks from a branch, and held out a pitcher of water for other birds to alight on and drink.
Limits to the Possibilities of Hybridisation Hybrids can apparently only be produced between species of the same natural family.
My own opinion is that the Lucknow race is the result of a hybridisation between the other three species.
But later experiments on hybridisation in sea-urchins have shown that a full hybrid of *Echinus* and *Sphaerechinus* may be purely paternal also.
During this period the zoologist had little inclination or inducement to carry on those investigations in hybridisation which were occupying the attention of some botanists.
Apart from the fact that plants lend themselves to hybridisation work more readily than animals, there was probably another reason why zoologists neglected this form of investigation.
After half a century of experimental hybridisation the determination of the relation of species and varieties to one another seemed as remote as ever.
Hybridisation experiments before Mendel there had been in plenty.
The number available for gardens has been increased by varieties raised by hybridisation and cross-breeding, and some of these are of much value.
It is generally accepted that these improved Hippeastrums are largely due to the hybridisation of some of these species, but there is considerable doubt regarding the parentage of some of these reputed hybrids.
It was held until recently that hybridisation is not possible except between closely related species and that even among these a successful hybridisation cannot always be counted upon.
The subject of hybridisationis dealt with in another part of this essay.
Hybridisation has in most cases affected our garden and cultivated plants so that they do not represent pure species but a mixture of species.
Godlewski used the same method for the hybridisation of the sea-urchin eggs with the sperm of a crinoid (Antedon rosacea).
It might be argued that in the case of heterogeneous hybridisation the sperm-nucleus does not fuse with the egg-nucleus, and that, therefore, the spermatozoon cannot transmit its hereditary substances to the larvae.
I hope I have made it clear that the hybridisation of orchids is the most fascinating of botanic studies at this time; which is all I have in view.
Some have not flowered yet, and therefore have received no name; but even of these it is worth while to give the parentage, seeing that there is no official record of hybridisation as yet.
Here the same oddity--due to natural hybridisation doubtless--is carried much further.
There may be other crosses probably, since no official record ofHybridisation exists as yet.
The discovery that fertile unions may be concerted between species, and even genera, differing in all visible respects, gives profound interest to the study of hybridisation in the scientific point of view.
Naudin's researches on Datura have shown how much variability, due to the hybridisation of any two species, may give rise to the appearance of there being many species.
And Focke, with whom I have been in correspondence from the first, and who does understand the theory, writes that in his opinion it will 'solve the whole mystery' of natural hybridisation in relation to artificial.
As regards the isolation of species I do not understand why you should suppose that the facts of hybridisation to which you allude should in any way modify my 'belief.
I did not know that there were so many cases of graft-hybridisation in potatoes.
I well know the large amount of natural as well as artificial hybridisation that goes on.
The above list will hopefully give you a few useful examples demonstrating the appropriate usage of "hybridisation" in a variety of sentences. We hope that you will now be able to make sentences using this word.
