TRANSFORMISM 261 



functioning and habits that are suffered by the organism. They 

 are (i) Diseases^ that is, disorders of functioning due to intoxica- 

 tions, bacterial or parasitic infections ; deficiency-conditions due 

 to some defect in nutrition (as, for instance, thyroid-deficiency, 

 vitamin- deficiency) and so on. (Here, of course, we exclude 

 disease that may possibly be " transmitted by heredity," as in 

 gout, rheumatism, possibly cancer and epilepsy.) There are also 

 disorders of growth, etc. (2) Mutilations may be traumatic in 

 nature, that is, the results of " accidents," say, losses of bodily 

 parts, such as limbs. (3) They may be the results of some 

 operative interferences carried out experimentally : castration, 

 circumcision ; the removal of some bodily part, as in the docking 

 of the tails of some dogs ; section of a nerve, blinding ; inter- 

 ference with an embryonic process, etc. In extreme cases 

 mutilations are fatal injuries, as in the results of accidents, many 

 experimental conditions, or diseases that lead to death. But many 

 prominent mutilations are consistent with normal, reproductive 

 life, as in the human conditions of partial or total blindness, the 

 excision of bodily parts, such as a kidney, the loss of much lung 

 tissue by tuberculosis, etc. In experimental conditions such 

 mutilations are deliberately caused and are intended to have some 

 bearing on the general problem of the inheritability of mutilations. 

 (Weismann's experiments on cutting off the tails of rats, for 

 instance.) It is such mutilations as are compatible with continued 

 reproductive life that we consider later on. In general, 

 mutilations must be regarded as disabilities. In the cases of men 

 and women, living in civilized communities, this may not be the 

 case. Nor in the cases of experimental animals, or those that 

 are domesticated or are living under laboratory conditions need 

 a mutilation be a disability. But in wild nature, and under the 

 stress of severe competition, all such mutilations as we have 

 indicated, or all malformations, or all results of accident or disease 

 must be regarded as, to some extent, disabilities. We emphasize 

 the contrast between them and adaptations — which tend, in 

 general, to the increased power, on the part of the organism, over 

 some part of its natural environment. 



876. Transformism by Acquirement. Just as in the cases 

 of fluctuations, mutations and combinations of Mendelian char- 

 acters, acquirements may be the materials for selection. It 

 cannot be doubted that a positive adaptation of behaviour. 



