HISTORICAL INTRODUCTION xxi 



structures are so closely associated in Salamandra that their relations 

 were only understood when the histologist Leydig examined them 

 microscopically in 1853. Judging from appearances in one of his 

 figures Gravenhorst seems to have found the receptaculum seminis 

 — later discovered by Rathke, Leydig, and von Siebold. His figures 

 of the developing larvae are better than those of Funk and Rusconi's 

 earlier drawings. Jacobson (18 17) describes the relations of the 

 anterior abdominal and renal portal veins in the Batrachia and Sala- 

 mander, and concludes, as Townson had done before him, that the 

 bladder in these animals is in no sense a urinary bladder, since its 

 structure is entirely different, and the ureters are not related to it as 

 they should be in a true urinary bladder. A brief but accurate 

 account of the auditory organ of the Salamander was published in 

 18 18 by Pohl. He describes the bony capsule, the external vacuity 

 closed by the 'cartilaginous operculum' discovered by Zinn, and the 

 entry of the auditory nerve. He calls the vacuity the 'fenestra vesti- 

 buli' as in modern usage. He describes the three semicircular canals 

 and their ampullae, and gives a figure of the operculum and the 

 fenestra which it closes. C. A. S. Schultze in 1 8 i 8 was the first to 

 reveal a curious osteological point in the terrestrial Salamander, viz. 

 that the transverse processes of the vertebrae are bifid, and articulate 

 with the bifurcated ends of the ribs. In the same year Meckel pub- 

 lished a comparison of the hyobranchial skeleton of Salamandra and 

 Triton, which, however, was based largely on Cuvier. The same 

 author's treatise on comparative anatomy is a useful summary of 

 existing knowledge, but perpetuates many errors. He asserts that 

 there is only one auricle of the heart in the Amphibia, and that it 

 contains mixed blood, but admits that in Salamandra and Triton the 

 auricle is divided by a well-marked constriction into an anterior 

 larger and a posterior smaller section. He mentions that he sought 

 for a carotid gland in Salamandra, but was unable to find it, although 

 he was more successful in other Amphibia, 



The third encyclopedic treatise on comparative anatomy to be 

 published in the early years of the nineteenth century was the Lehr- 

 buch of C. G. Carus, the first edition of which appeared in 1 8 1 8 and 

 the second in 1834. Carus had evidently dissected several examples 

 of S. maculosa more or less carefully, so that this work is not entirely 

 a compilation. He describes the valve in the nostril^ which he says 

 is like an eyelid, and noted its relation to buccal respiration. He 

 agrees that the bladder is only a water-holder, and even regards it as 

 a possible respiratory organ, since it is analogous to the allantois of 

 ^ Not, however, present in the Salamander. 



