Page:Popular Science Monthly Volume 20.djvu/683

Rh and attests the faculty it has of suiting itself to those external conditions which are most favorable to its life-habits. We see also how the plants of the earth have undergone improvement in regard to the length of their life under the influence of external conditions and by means of their power of variation, and can conceive how development of this kind can and will go on; for a cessation of the process is not possible.

It is true that not only certain species but whole genera and whole families as well appear now to be firmly fixed as to their life-habits and the longevity of their individuals; such plants, in view of the certain mutability of external conditions must either become migratory, or, if they can not change, must eventually give way to better adapted kinds. Other species, on the contrary, are capable of improvement; their individuals vary among themselves as to the habit and duration of their life, easily adapt themselves to changing conditions, and are able to adopt other life-habits. These changes in life-habit are accompanied step by step by a morphological adaptation of the organs, and thus from species having a definite term of life may be developed new species with other terms of life. The formation of annual species appears especially to be making a progress which began when a periodical took the place of a uniform climate. These species are, on account of the abundance of their rapidly maturing fruit, capable of a rapid improvement, and have had their spread facilitated since the appearance of man, who by his methods of cultivation makes the ground fit for them in places where they otherwise would not thrive.



CCIDENTAL burns and scalds, even when not very severe, extensive, or dangerous, commonly cause so much pain for an indefinite time, depending probably as to duration and severity a good deal on the age of the sufferer, and on the greater or less degree of sensitiveness of the individual's skin or constitution—not forgetting I the feverish reaction, and the dangerous internal secondary inflammations that are apt to follow in some cases—that any easily applied and quickly available remedy and relief, without perhaps the immediate necessity of calling in professional assistance, will be acknowledged as a boon by most persons; and especially so, when it is remembered that the sooner the agonizing burning pain in the part can be allayed, the less chance there is of dangerous secondary effects, besides sloughing, etc., so severely trying to children and old persons.

The usual first applications to these painful injuries, whether 