No. 485] NOTES AND LITERATURE 343^ 



certain barbed hairs from caterpillars of the brown-tail moth, when 

 applied to the skin, may cause a severe inflammation. Dr. Tyzzer 

 has found that these hairs occur over "two velvety brown spots which 

 appear on the dorsal aspect of the fifth and sixth segments after the 

 first molt." Similar spots are found after each succeeding molt up 

 to the last two spring molts, when they appear on all segments from 

 the fifth to the twelfth inclusive. At this time they occur also in 

 relation with the lateral tubercles of the same segments, so that the 

 caterpillar becomes much more poisonous than in its young stages. 



elevations upon the caterpillar; the barhs. which at iiiK-rvals tend to 

 encircle the hair, point outward. If these hair>. which arc ca>ily 

 detached, are rubbed upon the skin they work their way inward, 

 pointed end foremost. It was supposed that the irritation which 

 followed was purely mechanical. Dr. Tyzzer has demonstrated a 

 chemical poison in the following manner. If the hairs are placed in 

 a drop of blood between a slide and cover glass, a modification of 

 the red corpuscles takes place at the apex of the hair. There the 

 rouleaux are broken up; the corpuscles shrink and become at first 

 spiny, and then spherical. That this is not a physical phenomenon 

 is shown by substituting hairs of similar shape from the tussock moth, 

 when no reaction occurs. It is believed that a poisonous substance is 

 emitted from the apex of the hair, although no pore is visible. If the 

 hair is broken the reaction occurs about the fracture, but otherwise only 

 at the pointed extremity. The poisonous substance is not destroyed 

 by baking the hairs for one hour at 110° C, but is destroyed at 115°. 

 In the latter case the hairs produce no dermatitis when applied to the 

 skin, and no reaction in the drop of blood. The poison is insoluble 

 in alcohol, acetone, chloroform, ether, acetic acid, and dilute liydio- 

 chloric acid. It appears, however, to dissolve in distilled water at (10° 

 C, and a further chemical study is in progress. 



In regard to animal coloration it may be noted tliat tlie cater- 

 pillars of the tussock moth, said to present 'waniiiiir c()h)rs,' have 

 non-poisonous hairs; those of the lo moth, with a iiriH ii 'protective 

 coloration' are somewhat poisonous; and the poisonoiH hrown-tail 

 caterpillars have neither a warning nor a [>roteetive color. All three 

 forms, moreover, are eaten by birds. 



Divided Eyes of Insects.— G. D. Shafer has studied the <livided 

 eyes in certain Odonata and Diptera ' and has followed tlu' late sta-es 



