AND THE LOWER ANIMALS. 7 



which is familiar, at least by name, to most cultivated 

 minds. To tell the truth, it comprises most of the 

 others. This is why I have attempted to treat of it 

 in its entirety; hoping thus to afford to all serious 

 readers a general notion of the wonderful phenomena 

 presented by the development of living beings. 



The word metamorphosis has been for a long while 

 employed in a restrained and an inaccurate sense. 

 By it have been designated the very important 

 changes undergone by certain animals, insects in 

 particular, after proceeding from the egg. There was 

 thus made of these alterations a group of phenomena, 

 quite separate and distinct from those presented in 

 the formation of the embryos of ordinary ovipara. 

 With far more reason, we should regard them as 

 having at most a very remote analogy with those 

 processes observed in the development of vivipara. 

 The term metamorphosis has been almost exclusively 

 applied to modifications either of external form or 

 of some extensive apparatus influencing directly the 

 mode of life of the animal. 



These were serious errors. The nature of a phe- 

 nomenon does not alter with the locality in which it 

 takes place, nor with its greater or lesser extent. As 

 regards the passage from an egg-shell, or from the 

 uterus of the mother, as regards the modelling of a 

 single organ, or the formation of an entire body, 

 changes of form and function lose none of their 

 essential qualities. All are primarily caused by the 

 force which animates matter, which incessantly de- 

 stroys and rebuilds, through the assistance of the vital 

 power, those wonderful structures which we call living 

 beings. 



