DEVELOPMENT OF EYELIDS OF ALBINO RAT 27 



tion process has penetrated the entire thickness of the junction 

 epitheUum, and disjunction soon follows. 



The separation is also aided by the process of keratinization 

 manifesting itself in, 1) the developing hair folhcles derived from 

 the junction epithelium, and to a less degree, in, 2) the ducts of 

 the tarsal glands, and, 3) the cells lining the conjunctival furrow, 

 just prior to disjunction. 



Functionally, the period of attachment of the lids is related 

 to the maturing of the retina. At the time of formation and 

 fusion of the lids the retina has a very simple structure, consist- 

 ing principally of two broad bands of cells, while at the time of 

 disjunction all the layers of the mature retina are recognizable. 



LITERATURE CITED 



Ask, F. 1908 Ueber die Entwicklung der Lidrander, etc. Anat. Hefte, Bd. 36, 



S. 189-279. 

 Bach, L., und Seefelder, R. 1914 Atlas zur Entwicklungsgeschichte des 



menschlichen Auges. Wilhelm Engelmann, Leipzig and Berlin. 

 CoNTiNO, A. 1907 Ueber Bau und Entwickelung des Lidrandes beim Menschen. 



Arch. f. Ophthalmologie, Bd. 66, S. 505-577. 

 Donaldson, H. H. 1915 The rat. Data and reference tables for the albino 



rat (Mus norvegicus albinus) and the Norway rat (Mus norvegicus). 



Memoirs of The Wistar Institute of Anatomy and Biology, no. 6, 



Philadelphia. 

 EwETSKY, Th. 1879 Beitrage zur Entwickelungsgeschichte des Auges. Arch. 



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 NtrssBAUM, M. 1908 Entwickelungsgeschichte des menschlichen Auges, Graefe- 



Samisch Handbuch der Gesammten Augenheilkunde, 2nd edition, vol. 



2, part 1, pp. 52-53, Leipzig. 

 Schweiger-Seidl 1866 Ueber die Vorgange bei Losung der miteinander ver- 



klebten Augenlider des Foetus. Virchow's Archiv. f. Path. Anat. u. 



Phys., Bd. 37, S. 228-230. 

 Seiler, H. 1890 Zur Entwickelung des Conjunctivalsackes. Archiv. f. Anat. 



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Anat. u. Phys.) 



