602 MR. B. T. LOWNE ON THE SIMPLE AND COMPOUND EYES OF INSECTS. 
DIAGRAM. (Page 596.) 
Fig. 44. Scales of fractions of an inch, to which the succeeding diagrams are drawn. 
(For figs. 44 to 54, see page 596.) 
Fig. 45. The principal horizontal section of the cornea of Vespa (scale A). 
Fig. 46. The vertical meridian of the same eye (scale A). *■ 
Fig. 47. The curvature of the principal vertical meridian of a species of Syrphus 
(scale B). 
Fig. 48. The curvature of the principal horizontal meridian of JEschna grandis 
(scale A). 
Fig. 49. The principal vertical meridian of the same (scale A). 
Fig. 50. The horizontal meridian of Tabanus bovinus (scale A). 
Fig. 51. The principal vertical meridian of Musca vomitoria (scale B). 
Fig. 52. The vertical meridian of the eye of a Noctuid Moth (scale B). 
Fig. 53. The principal vertical meridian of the eye of Colias edusa (scale B). 
Fig. 54. The same, a meridian 30° from the last (scale B). 
Fig. 55. The same, a meridian at right angles to the last (scale B). 
