ARTHROPODA 



355 



lens cellular, being formed by a thickening of the epidermis. Beneath 

 the lens comes a layer of transparent cells, the vitreous body {2), and 



450 7 



Fig. 371. — Diagrammatic section through anterior (.4) and posterior (B) eyes of 

 Epeira diadema (after Grenacher). The hinder eye shows the inverted retina; i, 

 lens; 2, vitreous body; 3, epidermis, outside this, chitinous layer; 4, rhabdomes; 5, 

 retinal ceils; 6, capsule of eye; 7, rhabdomes of inverted eye. 



Fio. 372, — Section of compound eye of Forfictda (after Carriere, from Hatschek). 

 I, cuticula, producing the cornea of many lenses over the eye; 2, epidermis, which in 

 the eye forms the ommatidia; 3, basal membrane; 4, reentrant chitinous fold ('sclerotic') ; 

 5, rudimentary larval eye. 



behind this, in turn, the retina, consisting of visual cells vyhich, at the 

 one end, bear 'rhabdomes' (4 and 7), at the other pass into nerve fibres. 

 The retina and vitreous body, surrounded by pigment, form a spherical 



