436 



in salamanders with lungs, and which might be expected to exist 

 also in lungless forms. 



In my investigations, which were already complete when the paper 

 of Hopkins came into my hands, the following species have been used : 

 Plethodon cinereus, P. erythronotus, Desmognathus fusca, Salamandrina 

 perspicillata and Spelerpes fuscus. Some of these were studied by 

 Hopkins also. My own observations have revealed no trace of a 

 septum atriorum in any of the above-mentioned forms; the sinus- 

 atrium valve, however, is always functionally developed. In certain 

 species I have found, in the conus arteriosus, a spiral fold, whose 

 occurrence in the lungless salamander is difficult to explain. No 

 remnant of a vena pulmonalis was found. 



From the descriptions and figures of Hopkins, it is certain that 

 the sinus-atrium valve has been mistaken for a septum atriorum. This 

 error is in a measure explainable by the fact, that in the absence of 

 a septum (to which the valve is largely attached in salamanders with 

 lungs), the sinus-atrium valve of the lungless salamander applies it- 

 self directly to the wall of the heart. The relation of the valve to 

 the sinus opening is practically the same in the lungless salamanders 

 as in the forms with lungs: in both the opening is on the left side 

 of the valve. This fact explains the claim of Hopkins, that the 

 sinus venosus of the lungless salamander opens iuto the left auricle. 

 In view of the above, it is unnecessary to say that this claim lacks 

 support. 



The results of Hopkins's work have been adopted by Bethge (4), 

 but apparently without personal investigation. 



Literature. 



1) Beuner, Proceedings of the Indiana Academy of Science. Indiana- 

 polis, 1897. 



2) Hopkins , The Heart of some lungless Salamanders. American 

 Naturalist, Vol. 30, 1896. 



3) Fritsch, Zur vergleichenden Anatomie des Amphibienherzens. Archiv 

 für Anatomie und Physiologie, 1869. 



4) Bethge, Das Blutgefäßsystem von Salamandra maculata, Triton 

 taeniatus und Spelerpes fuscus ; mit Betrachtungen über den Ort der 

 Atmung beim lungenlosen Spelerpes fuscus. Zeitschr. f. wiss. 

 Zoologie, Bd. 63, 1898. 



