82 THE LUNGS, BY FRANZ EILHARD SCHULZE. 



so intercalated between the arterial retia that a transverse 

 section of the entire mass exhibits arterial and venous tubules 

 in tolerably equal amount, and in close juxta-position. 



The continuous epithelial investment that lines the internal 

 surface of every swimming-bladder, is composed in the Sturgeon, 

 and, according to Leydig, in Polypterus bichir also, of columnar 

 ciliated cells ; in the osseous fishes, on the other hand, there 

 is a single layer of tesselated epithelial cells, which differ 

 from those covering the capillary plexuses arising from the 

 arterial retia, in being less flattened or more cubical, in pos- 

 sessing cloudy granular contents, and consequently in presenting 

 the appearance of gland cells. Their glandular function is 

 rendered still more probable by the circumstance that they 

 completely line, as a kind of glandular epithelium, the lacuni- 

 forrn or purse-like inflections of the capillary bodies. 



PRINCIPAL WORKS ON THE FINER STRUCTURE OF THE LUNGS 

 AND SWIMMING-BLADDER OF FISHES. 



BISCHOFF, Lepidosiren paradoxa, 1840. 



HYRTL, Lepidosiren paradoxa, 1845. 



PETERS, Ueber die Lungen von Rhinocryptis, in MULLER'S Archiv, 



1845. 



FISCHER, Versuch iiber die Schwimmblase der Fische, 1795. 

 JACOBI,. De vesica aerea piscium, 1840. 



BERLAK, Symbolae ad anatomiam vesicae natatoriae piscium, 1834. 

 VAN DER HOEVEN, Ueber die zellige Schwimmbkse des Lepidosteus. 



MULLER'S Archiv, 1841. 

 J. MULLER, Vergleich. Anatomic des Gefassystemes der Myxino'iden, 



1841. Und Ueber die Eingeweide der Fische ; in den 



Verhandl. der Berliner Akademie, 1845. 



REINHARDT, Om svommeblaeren hos Familien Gymnotini, 1852. 

 LEYDIG, Anatom. histolog. Untersuchungen iiber Fische und Reptilien, 



1853. 

 LEYDIG, Kleinere Mittheilungen zur thierischen Gewebelehre. 



MULLER'S Archiv, 1854. 



, I^ehrbuch der Histologie, 1857, 



