Weismann's " Regeneration." 

 By Professor Marcus Hartog, D.Sc. 



Forewords. 



The following abstract of certain principles of controversy implied 

 in Prof. August Weismann's paper on " Eegeneration " in the April 

 number of Natural Science, is not intended to be of the nature of 

 "invectives, sarcasm, or derision" (p. 323); for these weapons, the 

 matter is far too serious. The human love for a complete system is 

 so great that any clearly expounded system that covers a very large 

 number of well-known facts is sure to be widely adopted, so long as 

 those other facts that are incompatible with that system are unknown 

 or ignored. Weismann's own contributions to our knowledge of facts 

 are so numerous, careful, exact, and important, his earlier theoretical 

 work is so valuable in every way, that his name added weight to his 

 " Systema Generationis " even in its earlier, recalled editions. His 

 candour in admitting errors therein, when they had been demonstrated 

 to the world, his unremitting patience and ingenuity in rebuilding his 

 edifice after such a ruin as befel its foundations in his papers on the 

 meaning of sexual reproduction, are deserving of our warmest admira- 

 tion and sympathy. We owe him a great and enduring debt for clearing 

 our ideas, for making us give reasons for our faith, for banishing many 

 an old error from science. In his last paper, however, of which he 

 says, " I have written it rather for the supporters than for the 

 opponents of my views," he has pursued a course fraught with dangers, 

 masked by the greatness of the authority of his name, and only to be 

 averted by being brought clearly into light. The canons of argument 

 and ethic which present these dangers are therefore summarised, with 

 quotations from his text in which they are exemplified ; and this also 

 is done for the benefit of those for whom the paper is written — " the 

 supporters rather than the opponents " of the germ plasm hypothesis. 

 For their benefit again it is desirable to point out that " Auslosung " 

 is used by Hertwig in its current technical physiological sense as 

 equivalent to " discharge " — of gunpowder, not of a cargo-boat ; the 

 connoted " setting free " is a setting free of energy, not of matter ; and, 

 consequently, its translation by " liberation " in this paper is incorrect, 



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