[225] It is just possible that the reverse may be true, vide note on p. [640]. If however, as is most probable, the statement in the text is correct, the valves at the mouth of the ventricle in Teleostei are not homologous with those of the Amniota; the former being the distal row of the valves of the conus, the latter the proximal.
[226] If Tonge is correct in his statement that the semilunar valves develop at some distance from the mouth of the ventricle, it would seem possible that the portion of the truncus between them and the ventricle ought to be regarded as the embryonic conus arteriosus, and that the distal row of valves of the conus (and not the proximal as suggested above, p. [639]) has been preserved in the higher types.
[227] In Mammalia the superior mesenteric artery arises from the vitelline artery, which may probably be regarded as a primitive cæliaco-mesenteric artery.
[228] The mandibular artery is stated by Götte never to be developed in Teleostei, but is distinctly figured in Lereboullet (No. [71]).
[229] In my account of the Amphibia, Götte (No. [296]) has been followed.
[230] His (No. [232]) describes in Man two ventral continuations of the truncus arteriosus, one derived from the mandibular artery, forming the external maxillary artery, and one from the hyoid artery, forming the lingual artery. The vessel from which they spring is the external carotid. These observations of His will very probably be found to hold true for other types.
[231] J. Müller holds that this sack is not rhythmically contractile.
[232] Stannius, Vergleich. Anat., p. 251.
[233] This statement of Götte’s is opposed to that of Rathke for the Amniota, and cannot be considered as completely established.
[234] Rathke’s account of the vena renalis advehens is thus entirely opposed to that which Götte gives for the Frog, but my own observations on the Lizard incline me to accept Rathke’s statements, for the Amniota at any rate.