THE SPECIES 269 



of the individual organism has made us familial. They are 

 therefore analogies, and in the present state of our knowledge 

 we cannot look for more. These analogies have the further 

 advantage that they do not lead us into speculations concern- 

 ing the existence of impossible ancestors, but simply indicate 

 the given relations. There can be no doubt that the melody 

 of genesis in mammals repeats in its opening measures that 

 of fishes, and diverges therefrom at a certain point. This 

 is the material that we have before us ; we have nothing 

 further. From it I conclude merely that, at the time before 

 there were any mammals, the mammalian melody had not 

 struck up. 



It is quite possible that the introduction of new melodies 

 coincides with changes in the medium ; but of this we have no 

 proof. One thing only I assume as certain — that when the ^ 

 new melody struck up for the first time, it did so in the 

 way that we can still observe at the present day, when we 

 compare together the shaping process in two related animal 

 forms. That is all one can afhrm. 



But it is a good deal, for the idea of an invasion by new ./ 

 melodies according to plan gets us out of the difficulty of 

 appealing to chance to explain the genealogy of animals. 

 The genealogical tree becomes a living structure developed in 

 accordance with plan, and, under compulsion from within, 

 perpetually forms new growths of the same kind. 



I consider that to compare this inner urge with a psychic / 

 affect is merely a sign of the inertia of the powers of our 

 human imagination, which is unable to free itself from a highly 

 deceptive tendency to anthropomorphose natural processes. 

 If Lamarckism would but throw off its psychological wrap- ^ 

 pings, it would pass over straightway into the biological 

 doctrine of conformity with plan. 



