xxvi HISTORICAL INTRODUCTION 



have little relation to the objects they represent, and his description 

 is too meagre to throw any light on his methods, or to suggest an 

 explanation of his errors. Funk's account of the gut and male and 

 female genitalia is much better. He describes a three-lobed testis 

 (it is usually two-lobed), and he made a serious attempt to unravel 

 the relations of the genital glands and ducts — a full understanding 

 of which, however, was beyond the technique of his time. Two years 

 later Gravenhorst materially improved on Funk's descriptions of the 

 genitalia. 



Cachet's paper of 1 827MS an interesting first-hand account of the 

 feeding and reproductive habits, metamorphosis, and regeneration 

 in the Salamander, but it contains little that is new. A year later 

 Siebold published his inaugural dissertation on the Salamander and 

 Triton. It is a remarkable and important maiden effort. He is the 

 first to trace accurately and in detail the metamorphosis of the larval 

 hyobranchial skeleton and musculature into that of the adult. He 

 gives a very good description with figures of the larval and adult 

 states, and also an excellent illustrated account of the anatomy of 

 metamorphosis, especially as regards colour, gills, operculum, and 

 tail. It is a very instructive study in the physiology of adaptation, 

 and of the phenomena which accompany the change over from aqua- 

 tic to terrestrial life. He shows further how metamorphosis may be 

 controlled or modified by varying the conditions. A sketch of the 

 development of the internal organs is included, and there is a section 

 on the myology of the tongue and hyoid, in which the movements of 

 the tongue are explained. 



The first statement of the discovery of the posterior lymph hearts 

 of the Frog was made by J. Miiller in September 1832. A year later 

 the anterior lymph hearts were found, not only in the Frog and Toad 

 but also in the Salamander and Lizard. Miiller observed the con- 

 traction of the hearts, and noted that the rate was peculiar to the 

 organ, and different from that of the heart and lungs, nor were the 

 pulsations of the two sides synchronous. The hearts contained a 

 clear lymph and not blood. The methods employed by Miiller in the 

 investigation were mercury injections and inflations, and he claims 

 that a pulsating lymphatic organ had not previously been seen. He 

 states that the posterior lymph hearts are difficult to find in the Sala- 

 mander, but that they are in the same position as in the Frog. Panizza 

 had already seen the lymph hearts of the Frog in 1830, but had not 



^ The volume is dated 1827, but the author refers to an incident which happened 

 in April 1828. He states that his plates were being published elsewhere, but so far no 

 such publication has been traced. 



