ood supply, etc. On the other hand, there are factors which, although having inherited bases, owe their expression almost wholly to outside influences. Professor Morgan, for example, has found a strain of fruit flies whose offspring in cold weather are usually born with supernumerary legs. In hot weather they are practically normal. If this strain were bred only in the tropics, the abnormality would probably not be noticed; on the other hand, if it were bred only in cold regions, it would be set down as one characterized by duplication of limbs. The heredity factor would be the same in each case, the difference in appearance being due merely to temperature.
Mere inspection does not always tell whether some feature of an individual is more affected by changes in heredity or changes in surroundings. On seeing a swarthy man, one may suppose that he comes of a swarthy race, or that he is a fair-skinned man who has lived long in the desert. In the one case the swarthiness would be inheritable, in the other
Who Murdered Mr. Malone? Book 1 of the Garden G... Read more
After finding the body of a dragon in a metalli... Read more
*This is a stand-alone book in the Fearsome Ser... Read more
Fans of the Hunger Games and Sci-Fi Thrillers will... Read more
While rumors of monsters rising in the south bring... Read more
See it as donating a moment of your social media time, every little thing helps us improve and stay online.
The list of books below is based on the weekly downloads by our users regardless of eReader device or file format.
See more popular titles from this genre.