2 20 THE HISTORY OF CREATION. 



influences of the surrounding outer world, assumes certain 

 new peculiarities in its vital activity, composition, and form 

 which it has not inherited from its parents ; these acquired 

 individual qualities are opposed to those which have been 

 inherited, or, in other words, those which have been trans- 

 mitted to it from its parents or ancestors. On the other 

 hand, we call Adaptability (Adaptabilitas), or Variability 

 (VariabiHtas), the capability inherent in all organisms to 

 acquire such new qualities under the influence of the outer 

 world. (Gen. Morph. ii. 191.) 



The Tindeniable fact of organic adaptation or variation is 

 universally known, and can be observed at every moment in 

 thousands of phenomena surrounding us. But just because 

 the phenomena of variation by external influences appear so 

 self-evident, they have hitherto undergone scarcely any 

 accurate scientific investigation. To them belong all the 

 phenomena which we look upon as the results of contracting 

 and giving up habits, of practice and giving up practices, or 

 as the results of training, of education, of acclimatization, of 

 gymnastics, etc. Many permanent variations brought about 

 by causes producing disease, that is to say, many diseases, 

 are nothing but dangerous adaptations of the organism to 

 injurious conditions of life. In the case of cultivated plants 

 and domestic animals, variation is so striking and powerful 

 that the breeder of animals and the gardener found their 

 whole mode of proceeding upon it, or rather upon the inter- 

 action between these phenomena and those of Inheritance. 

 It is also well known to every one that animals and plants, 

 in their wild state, are subject to variation. Every syste- 

 matic treatise on a group of animals or plants, if it were to 

 be quite complete and exhaustive, ought to mention in every 



