Chap. XXVII. OF PANGENESIS. 391 



homogeneous gelatinous protozoon to vary and assume a 

 reddish colour, a minute separated particle, would naturally, 

 as it grew to full size, retain the same colour ; and we should 

 have the simplest form of inheritance. 70 Precisely the same 

 view may be extended to the infinitely numerous and diversi- 

 fied units of which the whole body of one of the higher 

 animals is composed; the separated particles being our 

 geminules. We have already sufficiently discussed by impli- 

 cation, the important principle of inheritance at corresponding 

 ages. Inheritance as limited by sex and by the season of the 

 year (for instance with animals becoming white in winter) is 

 intelligible if we may believe that the elective affinities of the 

 units of the body are slightly different in the two sexes, 

 especially at maturity, and in one or both sexes at different 

 seasons, so that they unite with different geminules. It 

 should be remembered that, in the discussion on the abnormal 

 transposition of organs, we have seen reason to believe that 

 such elective affinities are readily modified. But I shall soon 

 have to recur to sexual and seasonal inheritance. These 

 several laws are therefore explicable to a large extent 

 through pangenesis, and on no other hypothesis which has as 

 yet been advanced. 



But it appears at first sight a fatal objection to our hypo- 

 thesis that a part or organ may be removed during several 

 successive generations, and if the operation be not followed 

 by disease, the lost part reappears in the offspring. Dogs and 

 horses formerly had their tails docked during many genera- 

 tions without any inherited effect; although, as we have seen, 

 there is some reason to believe that the tailless condition of 

 certain sheep-dogs is due to such inheritance. Circumcision 

 has been practised by the Jews from a remote period, and in 

 most cases the effects of the operation are not visible in the 

 offspring ; though some maintain that an inherited effect does 

 occasionally appear. If inheritance depends on the presence of 

 disseminated gemmules derived from all the units of the body, 



7e This is the view taken by Prof. elterlichen und im kindlichen Orga- 



fiaeckel, in his ' Generelle Morpho- nismus, die Theilung dieser Materie 



logie' (B. ii. s. 171), who says: bei der Fortpflanzung, ist die Ursache 



" Lediglich die partielle Identitat der der Erblichkeit." 

 specifisch constituirten Mateide im 



