i895- MORPHOLOGY AT THE NATIONAL MUSEUM. 269 



brate animals. The larva is possessed of three pairs of external gills 

 and a crested swimming tail. These larval features may be retained 

 and the animal remain aquatic for the whole of its life (Axolotl form), 

 or under certain condition sa metamorphosis may be passed through, 

 and the animal, destitute of gills and with a rounded tapering tail, 

 becomes terrestrial in habit.' The close relation existing between 

 developmental metamorphosis and the dimorphic metamorphosis of 

 Amhlystoma finds for this preparation a fitting place at the close of the 

 developmental series. 



The plate illustrating this article has been prepared from a 

 couple of photographs taken by Mr. A. Gepp, of the Botanical 

 Department of the Museum. I offer him hearty thanks for the 

 trouble he has taken. 



W. G. RiDEWOOD. 



