448 THE SUPPOSED TRANSMISSION OF MUTILATIONS. 



prove a transmission of acquired characters have been refuted, and 

 that the only firm foundation on which this hypothesis has been 

 hitherto based has been destroyed. We shall not be obliged, in 

 future, to trouble about every single so-called proof of the trans- 

 mission of mutilations, and investigation may be concentrated upon 

 the domain in which lies the true decision as to the Lamarckian 

 principle, it may be concerned with the explanation of the ob- 

 served phenomena of transformation. 



If, as I believe, these phenomena can be explained without 

 the Lamarckian principle, we have no right to assume a form of 

 transmission of which we cannot prove the existence. Only if it 

 could be shown that we cannot now or ever dispense with the 

 principle, should we be justified in accepting it. I do not think 

 that I can represent the state of the subject better than by again 

 referring to the metaphor of the ship. We see it moving along 

 with all sails set, we can discern the presence of neither paddles 

 nor screw, and as far as we can judge there is no funnel, nor any 

 other sign of an engine. In such a case we shall not be justified 

 in concluding that an engine is present and has some share in the 

 movement of the vessel, unless the movement is of such a kind that 

 it is impossible to explain it as due to the unaided action of the 

 wind, the current, and the rudder. Only if the phenomena pre- 

 sented by the progress of organic evolution are proved to be inex- 

 plicable without the" hypothesis of the transmission of acquired 

 characters, shall we be justified in retaining such an hypothesis. 



