You speak of these animals as having been exposed to a vast range of climatalchanges from before to after the Glacial period.
Now such cases seem to me very striking, as showing how little relation some variations have to climatal conditions.
The earlier part of this post-glacial or antediluvian period was one of mild climatal conditions, followed by a slight return of the conditions of the previous glacial age.
There were no doubt also climatal changes in the course of the age, which may have tended to the remarkable mixture of animal types in its deposits.
These people have gone on without any physical cataclysm, or change of fauna, or geographical or climatal changes of any magnitude, into the ages of bronze and iron and of the modern civilisation.
Type after type becomes highly specialised in adaptation to local or climatal conditions, and then dies out, giving room for some other type to arise and be specialised in harmony with the changed conditions.
When the snow-fields, as in the Alps, were much more extensive than they are at present, the glaciers which radiated from them would be more sensitive to minor climatal change.
Climatal changes during that time destroyed the mass of the southern flora which had thus reached Ireland, the survivors being species such as were most hardy (saxifrages, heaths, etc.
The process of diffusion may often be very slow, being dependent on climatal and geographical changes, or on strange accidents, but in the long run the dominant forms will generally succeed in spreading.
It cannot be denied that we are as yet very ignorant of the full extent of the various climatal and geographical changes which have affected the earth during modern periods; and such changes will obviously have greatly facilitated migration.
But the geographical and climatal changes, which have certainly occurred within recent geological times, must have interrupted or rendered discontinuous the {354} formerly continuous range of many species.
To these ever-varying geographical and climatal conditions the state of the animate world has been unceasingly adapted.
The climatal features of Seriland are somewhat affected by the pronounced topographic features of the district.
A climatal characteristic of the province is two relatively humid seasons, coinciding with the two principal inflections of the annual temperature-curve, i.
On the re-emergence of the land such of these species as remained would again extend themselves over their former areas of distribution, in so far as the new climatal and other conditions would permit.
Further, we must not assume that the climatal conditions of the northern hemisphere were in the coal period at all similar to those which now prevail.
He has altered the climatal condition of whole tracts of country, and changed the physiognomy of the globe.
Yet domesticated animals and plants can hardly have been exposed to greater changes in their conditions than have many natural species during the incessant geological, geographical, and climatal changes of the whole world.
Callirhoe is strong presumptive proof that the latter is a true species, and no climatal or insular modification of the former.
This, however, is simply in harmony with the belief which we have already expressed, that climatal causes, when taken singly and alone, are not of primary importance whilst discussing the question of specific modification.
The two principal conditions on whichclimatal causes generally may be said to rest, are latitude and altitude.
Climatal Revolutions as an Agent in Producing Organic Changes.
The great difference presented by the birds of these islands as compared with those of the equally remote Azores and Bermudas, is sufficiently explained by the difference of climatal conditions.
The intolerance of organisms to climatal changes is nowhere more evident than in the varieties, or species, as we would term them, of mankind.
These general conclusions concerning the climatal limitations of man would be unassailable were it not for the history of the negro in North America.
These animals were thoroughly successful in meeting the climatal conditions of the region.
The camel is an even more striking instance in which the value of the creature depends upon climatal peculiarities.
If there was a difference in the climatal conditions of the high and low-level deposits, it might have produced some effect on the method of living, and on the implements of the men of the two periods.
Although the Pliocene deposits formed in high latitudes have to a great extent been swept away by the subsequent glacial wearing, they indicate by their fossils a climatal change in the direction of greater cold.
So far as the observer can judge, the climatal conditions and the other influences which affect the wear of rocks have not greatly varied in the past from what they are at the present day.
There are certain peculiarities of Mount Ætna which are due in part to its great size and in part to the climatal conditions of the region in which it lies.
It is therefore proper to state that there are many other actions besides those above noted which probably enter into those complicated equations which determine the climatal conditions of the earth.
But as these winds vary in the amount of the watery vapour which they contain, and as the surface of the land is very irregular, the rainfall is the most variable feature in the climatal conditions of our sphere.
An ordinary dwelling house sways and strains with the alternations of temperature and moisture to which it is subjected in the round of climatal alterations.
A large part of the difficulties which geologists encounter in endeavouring to account for the changes of the past arise from the evidences of great climatal revolutions which the earth has undergone.
In the chapter on climatal changes further attention will be given to the action of ocean currents from the point of view of their influence on the heat and moisture of different parts of the world.
It is, indeed, evident that a very slight change in the climatal conditions of this locality would establish a permanent accumulation of frozen water upon the summit of the mountain.
When, owing to climatal changes, a valley such as those of the Alps is occupied by a glacial stream, the new current proceeds at once, according to its evident needs, to modify the shape of its channel.
In the ordinary succession of seasons we often note the occurrence of winters during which the precipitation of snow is much above the average, though it can not be explained by a considerable climatal change.
The above statements as to the climatal effect of the ocean streams show us how important it is to obtain a sufficient conception as to the way in which these currents now move and what we can of their history during the geologic ages.
Honckenya peploides affords another illustration of the sexual arrangements in the flower being altered as it would seem by climatal conditions.
Temperature and climatal changes in general seem not to be without effect, as has been already mentioned in the case of Arenaria tetraquetra, which is polygamous when growing in mountain districts.
We have, however, farther to bear in mind the possibility of cataclysms or climatal changes which may have proved speedily fatal to many species over large areas.
Farther, not only have we varieties of man resulting from the slow operation of climatal and other conditions, but we have the sudden development of races.
This is admitted by Darwin, who gives other examples, though he insists much on the climatal variations which still remain in feral pigs.
Such examples show how unsafe it is to reason as to the rate of deposit in by-gone times, and when climatal and local conditions may have been very different from those at present subsisting.
The above list will hopefully give you a few useful examples demonstrating the appropriate usage of "climatal" in a variety of sentences. We hope that you will now be able to make sentences using this word.
