194 



COMPARATIVE ANATOMY. 



A well-differentiated Harderian gland is present in the whole 

 series of animals from the tailless Amphibia to the Mammalia. 

 Amongst the latter it is wanting in the Cetacea and Primates only. 



FIG. 159. DIAGRAM OF THE LACRYMAL APPARATUS OF MAN. 



TJ), lacryrnal gland, divided up into several portions ; **, ducts of the lacrymal 

 gland ; ft, puncta lacrymalia ; TR, TR 1 , tipper and lower lacrymal canals ; 

 /y, lacrymal sac ; D, naso-lacrymal duct. 



The Me ibo m ian glands, belonging to the group of sebaceous 

 glands, are confined to the Mammalia, and lie embedded in the 

 substance of the eyelids in the form of branched tree-like tubes 

 or clustered masses. They open on the free edge of the lid, and 

 produce a fatty secretion. 



BIBLIOGRAPHY. 



BERGET!, E. Seitrdge zur Anatomie dcs Sehoryanes der Fischc. Morphol. Jahrb. Bd. 



VIII. 1882. 

 BOLL. F. Zur Ana f omif! und Physiologic der Retina,. Arch. f. Anat. u. Physiol. 



1877, Physinl. A'-tliL 



CAKKIKKE. J Di- -'rhnrtmns. d-r Thiere Miim:hen und Leipzig, 1885. 

 HEIXEMANN, C. Bdtraye zur Anatomie der Retina. Arch. f. mikr. Anat. Bd. XIV. 



1877. 



KESSLER, L. Zur Entwicklung des Auges. Leipzig, 1877. 

 LEUCKART, K. Organologie dcs Auges. In A. Gracfe und Th. Saemisch, Handbuch 



der gesammten Augenheilkunde. Bd. I. Anatomie und Physiologic. 

 MANZ, W. Entw.-Gesch. des menschl. Auges. Ibid. 

 MULLER, H. GfesammeUe und hinterlassene Schriften zur Anatomie und Physiologic. 



des Auges. fferausgegeb. von 0. Becker. Leipzig, 1872. 

 MULLER, W. Ueb. die Stammcsentwick. des Sehorganes der Wirbelthiere. Festgabe 



von C. Ludwig. Leipzig, 1874. 

 SARDEMANN, E. Die Thraenendrusc. Preisschr. Frieburgi/B. 1884. Abstract in the 



Zool. Am. 1884. 

 SCHULZE, M. Die Retina. Strieker's Handbuch der Lehre von den Geweben. 



Leipzig, 1871. See also Archiv fur mikr. Anatomie, Bd. II., 111., IV., V., 



VI., & VII. 

 SCHWALBE, G. Lehrb. d. Anatomie der Sinnesorgane. Erlangen, 1883. 



AUDITORY ORGAN. 



It is very probable that the auditory organ, like those of 

 smell and taste, has been derived primitively from a modified 

 integumentary sense-organ (organ of the lateral line). The 



