GENESIS OF NASOLACRIMAL PASSAGES IX MAN 



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Figs. 10 unci 11 Photomicrographs of frontal sections in the region of the 

 developing nasolacrimal passages, from a human embryo aged forty-three days. 

 Note the anlagesof the nasolacrimal passages and that they are entirely separated 

 from the surface. The lacrimal-duct anlages are well advanced and show as 

 sprouts from the mother cord. The nasal end of the cord has not developed suffi- 

 ciently to come in contact with the mucous membrane of the inferior nasal meatus. 

 The lacrimal ducts are also some distance from the free borders of the eyelids at 

 this time. The section represented in fig. 10 is the most ventral of the series 

 and that represented in rig. 11 the most dorsal. Some of the intervening sections 

 of the series arc, of course, omitted. Embryo no. 3 — Hess, Cornell University 

 Series, n = anlage of nasolacrimal duct; m/=anlage of inferior lacrimal duct; 

 sup = anlage of superior lacrimal duct; e = eye. X 27. 



