264: BEATRICE WHITESIDE 
added that in the case of animals possessing a very large saccus 
this organ might transmit the sound waves from the skull into 
the ear. Wiedersheim thought this also highly probable. Sterzi 
maintained that the saccus in Rana had the same function as the 
other spinal meninges, namely, that of protecting the spinal 
cord. Carus (’41), who observed the calcareous matter in the 
saccus of snake embryos and the subsequent disappearance of 
the same, concluded that the lime was used for the growth of 
bone and was thus absorbed. Gaupp (’96) has accepted this 
theory in regard to Rana. In this case, the growth of bone took 
place in the adult frog as well as in the larva. Therefore, the 
saccus secreted lime throughout the life of the frog. 
Scott and Euclid Avenues, 
St. Louis, Mo. 
LITERATURE CITED 
ALEXANDER, G. 1890 Ueber Entwicklung und Bau der Pars inferior labyrinthi 
der hoeheren Saeugetiere. Denkschr. ak. Wiss. Wien math.-nat. K1. 
Bd. 60. 
1901 Zur Entwicklung des Ductus endolymphaticus. Arch. Ohren- 
heilk., Bday “52. 
Batrour, F. 1880 A treatise on comparative embryology. London. 
Buasius, G. 1681 Anatome animalium. Amstellodami. 
Borrrcuer, A. 1869 Ueber Bau und Entwicklung des Gehoerlabyrinths nach 
Untersuchungen an Saeugetieren. Verh. d. Kais. Leop.-Carol. Akad., 
Bd) °35. 
BurckHArpDT, R. 1892 Das Centralnervensystem von Protopterus annectens. 
Berlin. 
Burne, R. 1913 Note on the membranous labyrinth of Neoceratodus forsteri. 
Anat. Anz., Bd. 48. 
Catorr 1850 Sulla anatomia dell’Axolotl. Mem. Acad. se. instit., Bologna, 
eas. 
Carus, C. 1835 Traité élémentaire d’Anatomie comparée. (Trad. par Jour- 
dan.) Paris. 
1841 Merkwuerdige Anhaeufung mikroskopische Krystalle am Hin- 
terkopfe von Schlangenembryonen. Arch. Anat. u. Physiol. u. wissen- 
schaftl. Med. Mueller. 
Coaal, A. 1890 Ueber die sogenannten Kalksaeckchen an den Spinalganglien 
des Frosches und ihre Beziehungen zum Ductus endolymphaticus. 
Anat. Anz., Bd. 5. 
1890 I sacchetti caleari ganglionari e l’acquedotto del vestibolo 
nelle rane. Attiacec. Linc. (Mem. Se. fis. math. nat.) (4), vol. 6. 
Cornina, H. 1899 Ueber einige Entwicklungsvorgaenge am Kopfe der Anuren. 
Morphol. Jahrb., Bd. 27. 
