1 1 8 An Examination of Weismannism. 



In the second place, as a result of his more matured 

 reflection, Professor Weismann has himself perceived 

 a considerable number of the difficulties and objections 

 which I have set forth in the preceding chapters. 

 And not only has he thus anticipated many of my 

 criticisms ; but. as a result of doing so, he has changed 

 not a few of the most important parts of his previous 

 system, with the result of greatly improving it. 



But, in the third place, notwithstanding that his 

 remarkable power of speculative thinking is every- 

 where united with adequate knowledge in the sundry 

 branches of biological science with which it deals, 

 I confess to a serious doubt whether it has not been 

 permitted to enjoy an undue amount of liberty. If 

 only they can be laced together by a thread of logical 

 connexion, hypotheses are added to hypotheses in 

 such profusion as we are acquainted with in the works 

 of metaphysicians, but which has rarely been ap- 

 proached in those of naturalists. The whole mechanism 

 of heredity has been now planned out in such minute- 

 ness of detail and assurance of accuracy, that in reading 

 the account one is reminded of that which is given 

 by Dante of the topography of Inferno. For not 

 only is the " sphere " of germ-plasm now composed 

 of nine circles (molecules, biophores, determinants, ids, 

 idants, idio-plasm, somatic-idioplasm, morpho-plasm, 

 apical-plasm), but in most of these regions our guide 

 is able to show us such strange and interesting phe- 

 nomena, that we return to the fields of science with 

 a sense of having been indeed in some other world. 

 Or, to change the metaphor, if it be the case that 

 '• a true scientific judgement consists in giving a free 

 rein to speculation with one hand, while holding 



