76 ESSAY ON CLASSIFICATION 



be deprived of that great source of enjoyment and intellectual and 

 moral improvement which result from the contemplation of the 

 harmonies of an organic world, would involve a lamentable loss, and 

 may we not look to a spiritual concert of the combined worlds and 

 all their inhabitants in presence of their Creator as the highest con- 

 ception of paradise? 



SECTION XVIII 

 METAMORPHOSES OF ANIMALS 



The study of Embryology is of very recent date; the naturalists of 

 the past century, instead of investigating the phenomena accompany- 

 ing the first formation and growth of animals, were satisfied with 

 vague theories upon reproduction. ^'^^ It is true the metamorphoses of 

 Insects became very early the subject of most remarkable observa- 

 tions, but so little was it then known that all animals undergo great 

 changes from the first to the last stages of their growth, that meta- 

 morphosis was considered a distinguishing character of Insects. The 

 differences between Insects in that respect are, however, already so 

 great, that a distinction was introduced between those which un-. 

 dergo a complete metamorphosis, that is to say, which appear in three 

 successive different forms, as larvae, pupae, and perfect insects, and 

 those with an incomplete metamorphosis, or whose larvae differ little 

 from the perfect insect. The range of these changes is yet so limited 

 in some insects, that it is not only not greater, but is even much 

 smaller than in many representatives of other classes. We may 

 therefore well apply the term metamorphosis to designate all the 

 changes which animals undergo in direct and immediate succession^^^ 

 during their growth, whether these changes are great or small, pro- 

 vided they are correctly qualified for each type. 



The study of Embryology, at first limited to the investigation of 



^'^ Buffon, Discours sur la nature des animaux (Geneva, 1754); also in his Oeuvres 

 completes (36 vols., Paris, 1774-1804). 



^°^ I say purposely "in direct and immediate succession," as the phenomena of alter- 

 nate generation are not included in metamorphosis, and consist chiefly in the produc- 

 tion of new germs, which have their own metamorphosis; while metamorphosis proper 

 relates only to the successive changes of one and the same germ. 



