NOTES. 73 



It seems also exceedingly probable that " super- 

 larvation " does not occur only as in axolotl through 

 premature maturation of the reproductive organs, 

 but the phenomenon may develop itself more slowly 

 by a gradual creeping forward, as it were, of larval 

 features. Just as the adaptations acquired in, and 

 having relation to, later Hfe tend to show them- 

 selves in an early period of the development of the 

 individual and out of due season ; so do characters 

 acquired by the early embryo, and having relation 

 only to this early period of life tend to remain as 

 permanent structures, and by their invasion to perturb 

 the adult organization. Such perturbation may tend 

 either to simplification or elaboration. 



