xviii HISTORICAL INTRODUCTION 



John Hunter's work on the Amphibia, which must have occupied 

 his attention round about the year 1780, but which was not pub- 

 lished until modern times, is characteristic of his original and pene- 

 trating mind. There are eleven Hunterian preparations of Sala- 

 mandra still to be seen in the Hunterian museum. They illustrate 

 the abdominal viscera of male and female in some detail, and a 

 S. atra is shown with one of the two foetuses to which it is limited, 

 but this last preparation was presented by Buckland and is not 

 Hunterian. Hunter attempts an instructive comparison of Salaman- 

 dra and Triton in respect of their structure and reproductive habits, 

 with which he exhibits a greater familiarity than his predecessors, 

 and his interpretations are remarkably sound. As usual, however, he 

 did not concern himself with the work of others, and some of his 

 points, though original as far as he was concerned, were not new. In 

 his classification according to the structure of the heart he institutes 

 a group named the Tricoilia (= Reptiles and Amphibians) in which 

 the heart has three chambers — two auricles and one ventricle. This 

 classification was first printed in the posthumous work on the 

 Blood in 1794, but no details are given there, and the complete 

 scheme was only published long after Hunter's death. He included 

 the Salamanders in the group with the two-auricled heart, and was 

 therefore the first to perceive the essential structure of the Amphi- 

 bian heart. 



Blumenbach (1787) is the first author to mention all the points 

 which characterize the larval Salamander, viz. the external gills, the 

 four appendages, and the aquatic, as contrasted with the terrestrial, 

 type of tail. This may appear to be observation of an elementary 

 character, but we have seen that the external gills were completely 

 missed by the earlier naturalists, and even as late as 1800 Latreille 

 was denying their existence, whilst Saint-Julien in 1789 interprets 

 the gills as a pair of long fins, and failed to discover any traces of the 

 limbs. Blumenbach also held that female Salamanders which were 

 for months isolated from males nevertheless gave birth to young, 

 from which he concludes (i) that the eggs are not fertilized after 

 they are laid and that the Salamander is truly viviparous; and (ii) 

 that, as in the case of the fowl, a single act of fertilization is effective 

 for some time. He found that the Salamander was capable of 

 regeneration, and that if a third of the tail was cut off it could be 

 completely, but not quickly, regenerated. The first detailed descrip- 

 tion of the auditory organ of a Urodele is given by Scarpa (1789), 

 but his observations relate to the aquatic Salamander (Triton). 

 The essential facts are correctly stated, and he realized that Triton 



