MORPHOLOGY OF ANIMALS 



..e 

 — c 

 ac 



a 



Fic. 29. A, Human Eye, horizontal section ; e, corneal epithelium ; r, cornea ; ac, anterior 

 chamber ; i, iris ; cb, ciliary body ; /, lens ; pc, posterior chamber ; p, blind spot at point of 

 entrance of optic nerve ; m, macula, point of clearest vision ; r, retina ; ch, choroid ; sc, 

 sclerotic coats. B, Compound Eye of Arthropod, composed of many individual eyes or om- 

 matidia ; /, layer of corneae ; 2, crystalline cones; 3, retinulae, or sensory layer; n, nerve. 

 Dotted lines indicate that each ommatidium receives light from only a small part of the 

 arrow, thus constituting mosaic vision. (After Hatschek). 



