HISTORICAL INTRODUCTION xxvii 



observed them in the living animal, and hence was unaware that they 

 pulsated and were therefore hearts. 



Windischmann (1831) dissected five Salamanders, and describes 

 the 'finer' structure of the auditory organ. He was the first to observe 

 that the fenestra vestibuli (ovalis) is closed by a membrane to which 

 the operculum is related, the operculum itself not occurring in the 

 larval Salamander. His figure of the labyrinth is crude and distorted, 

 but he noted the absence of a cochlea and of the fenestra rotunda. 

 Bischoff (1832) gives a small and poor figure, but hardly any descrip- 

 tion, of the dorsal surface of the brain of Salamandra — a part of the 

 animal which had so far been almost entirely neglected. In 1832 

 Martin Saint-Ange confirms the existence of two auricles in the 

 heart of the Anura, and adds that in the Salamanders also there is 

 a small but distinct left auricle. 



The monograph by Panizza on the lymphatic system of Reptiles 

 published in December 1833 ^^ one of the most important of the 

 earlier works dealing with the comparative anatomy of this system. 

 He used injections of mercury, and coloured masses such as size, and 

 his material included representatives of most orders of Reptiles and 

 Amphibia. He discovered the anterior and posterior lymph hearts 

 independently of Muller, and proved by repeated experiments that, 

 as the lymphatics did not open into the gut and were peripherally 

 distinct from the true blood-vessels, they must therefore be re- 

 garded as an independent system. He found that in Salamandra the 

 lymphatics were developed to a prodigious extent, and that the net- 

 works were of astonishing minuteness. On the other hand the main 

 trunks were unusually capacious, and communicated on each side 

 with the anterior vena cava by valved apertures. There were further 

 openings posteriorly into the pelvic veins, and at this point a con- 

 tractile posterior lymph heart driving the lymph into the veins might 

 be present. He did not, however, find the latter heart in Salamandra. 

 The main lymphatic cistern in Salamandra extended from the anus 

 to the pylorus, expanding as it passed forwards. In the abdomen it 

 divided into two sinuses associated with the genitalia, which united 

 again anteriorly to form the thoracic duct. The latter bifurcated 

 in the neighbourhood of the heart, each division receiving the 

 lymphatics from the region of the fore-limbs and head of its side, 

 and opening finally into the subclavian of the same side by two or 

 three small apertures. In a later paper published in 1845 Panizza 

 regards the respiratory process in Salamandra as one of deglutition 

 of air, and he develops in detail the theory of the buccal force-pump 

 and explains the physiology of the muscles and skeleton concerned. 



