. The Journal of comparative neurology and psychology. ons concern the method of response of theanimals to light and gravity. Before entering into the discussion of the reactions, a word maybe said concerning the organs for the reception of light. These lie oneither side of the head, immediately posterior to the base of theantennae, upon the elevation bounding the antennal sulcus may be recognized by the brownish pigment which may be seen The Journal op Compaeative Necrology and Psychology.—Vol. XIX, No. 6. 722 Journal of Comparative Neurology and Psychology. through the chiti
. The Journal of comparative neurology and psychology. ons concern the method of response of theanimals to light and gravity. Before entering into the discussion of the reactions, a word maybe said concerning the organs for the reception of light. These lie oneither side of the head, immediately posterior to the base of theantennae, upon the elevation bounding the antennal sulcus may be recognized by the brownish pigment which may be seen The Journal op Compaeative Necrology and Psychology.—Vol. XIX, No. 6. 722 Journal of Comparative Neurology and Psychology. through the chitin overlying the light receptor apparatus. I havesectioned heads of the larvse and been enabled to study the histologyof the organs in Delafield hematoxylin stains. A median sectionthrough one organ is shown in the accompanying Fig. 1. In thisparticular section, the chitin overlying the area had been torn off bythe microtome knife, but in other sections, where, unfortunately, thehistological elements were not as well preserved as in the present one,. .**!©-^.it Fig. 1.—a, section through an eye-spot of a larva of Teneirio molitor atright angles to the surface of the body. 6, portion of chitin covering the eye-spot of another section, in Avhich the chitin overlying this eye-spot was canals running from the surface to the interior through the chitin arecharacteristic of the chitin over the whole of the head and not of this partof the body alone. the chitin was intact, and I have drawn in & a portion to show thecharacteristic structure. As Cole remarks, there are no lenses formedin the chitin over the eyes, nor is there any difference in the trans-parency of the chitin in these regions from that over other parts ofthe head. When the eyes are examined in the living animal, with ahand-lens, it is seen that the chitin is as dense and as opaque to lightas in other parts of the body. This fact, with the condition of theother elements of the eyes, indicates that the whole
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