10 INFLUENCE OF HUMAN ACTION. 
unquestionably tended to produce great changes in the hygro- 
metric, thermometric, electric, and chemical condition of the 
atmosphere, though we are not yet able to measure the force of 
the different elements of disturbance, or to say how far they 
have been neutralised by each other, or by still obscurer infiu- 
ences; and it is equally certain that the myriad forms of animal 
and vegetable life, which covered the earth when man first en- 
tered upon the theatre of a nature whose harmonies he was 
destined to derange, have been, through his interference, greatly 
changed in numerical proportion, sometimes much modified in 
form and product, and sometimes entirely extirpated.* 
* Man has not only subverted the natural numerical relations of wild as well 
as domestic quadrupeds, fish, birds, reptiles, insects, and common plants, and 
even of still humbler tribes of animal and vegetable life, but he has effected 
in the forms, habits, nutriment and products of the organisms which minister 
to his wants and his pleasures, changes which, more than any other manifesta- 
tion of human energy, resemble the exercise of a creative power. Even wild 
animals have been compelled by him, through the destruction of plants and 
insects which furnished their proper aliment, to resort to food belonging to 
a different kingdom of nature. Thus a New Zealand bird, originally gran- 
ivorous and insectivorous, has become carnivorous, from the want of its natural 
supplies, and now tears the fleeces from the backs of the sheep, in order to 
feed on their living flesh. 
All these changes have exercised more or less direct or indirect action on 
the inorganic surface of the globe; and the history of the geographical revo- 
lutions thus produced would furnish ample material for a volume. 
The modification of organic species by domestication is a branch of philo- 
sophic inquiry which we may almost say has been created by Darwin; but 
the geographical results of these modifications do not appear to have yet been 
made a subject of scientific investigation. 
I do not know that the following passage from Pliny has ever been cited in 
connection with the Darwinian theories, but it is worth a reference : 
‘* But behold a very strange and new fashion of them [cucumbers] in Cam- 
pane, for there you shall have abundance of them come up in forme of a 
Quince. And as I heare say, one of them chaunced so to grow first at a very 
venture; but afterwards from the seed of it came a whole race and progenie 
of the like, which therefore they call Melopopones, as a man would say, the 
Quince-pompions or cucumbers.”—PLiny, Vat. Hist., Holland’s translation, 
book xix., ¢. 5. 
The word cucumis used in the original of this passage embraces many of 
the cucurbitacee, but the context shows that it here means the cucumber. 
