168 (iVPSV AND BROWN-TAIL MOTHS. [Jan. 



The dermatitis produced by the nettling hairs is of two types, de- 

 pendent upon the number of these elements penetrating a given area. 

 The severe type is usually due to actual contact with caterpillars; the 

 milder scattered rash is due to nettling hairs blown in the air and lodg- 

 ing on the skin or on the undergarments as they hang drying. The 

 pathological process in the skin consists of necrosis of the epidermal 

 cells around the nettling hairs, the formation of spaces or microscopic 

 vesicles in the epidermis at the site of injury, and in inflammatory 

 changes about the vessels of the corium. 



Mice inoculated with active nettling hairs present lesions characterized 

 by a large amount of fluid exudate, while those inoculated with inacti- 

 vated nettling hairs show inflammation of the nature of a reaction clue 

 to the mechanical injury brought about by these elements. 



REFERENCE WORKS. 



1. Anderson, J., 1884. The urtieating properties of the hairs of some Lc]>i- 



doptera. Entomologist, 1884, XVII., 275. 



2. Balding, G., 1885. Urtieating properties of Lepitloptera. Entomologist, 



1885, XVIII., 41. 



3. Carter, W. A., 1903. (Quoted by Thresh. See No. 16.) Entomologist, 



1903. 



4. Clifford, J. R. S., 1885. The urtieating properties of the hairs of Por- 



thesia clirysorrlicea. Entomologist, 1885, XVIII., 22. 



5. Cockerel, T. D. A., 1885. The urticatiug hairs of Lepicloptera. Ento- 



mologist, 1885, XVIII., 75. 



6. Dimmock, G., 1882. On some glands which open externally on insects. 



1'vyche, 1880-82, III., 387. 



7. Fernald, C. H., and Kirkland, A. H., 1903. The brown-tail moth. Bul- 



letin Massachusetts State Board of Agriculture, 1903. 



8. Keller, C., 1883. (Quoted by Dimmoek.) Zur Kenntnis der Pinien - 



Prozessionsraupe (Gastropaclia s. Cnethocampa pityocampa) . Schweiz. 

 Forstzeitung, 1883, 117-126. 



9. Keller, C., 1883. Die brennenden Eigenschaften der Prozessionsraus 



Kosmos, 1883, XIII., 302. 



10. Kirby and Spenee. (Quoted by Thresh. See No. 16.) An introduction 



to entomology. Chapter on " Direct injury caused by insects." 



11. Meek, E. R., 1901. Further observations on the brown-tail moth. Bos- 



ton Medical and Surgical Journal, 1901, CXLIV., 657. 



12. Moore. Lepidoptera of Ceylon, II., 147. 



13. Rendall, P., 1884. Urtieating by Liparis chrysorrha>a. Entomologist, 



1884, XVII., 275. 



14. South, R., 1885. Urtieating hairs of some Lepidoptera. Entomologist, 



issr,, xvir., 3. 



15. Swinton, 1879. (Quoted by South. See No. 14.) Paper read before 



the Entomological Society, London, Aug. 6, 1879. 



16. Thresh, J. C., 1906. Caterpillar rash. Lancet, 1906, CLXXI., 2M. 



17. White, J. C., 1901. Dermatitis produce.! l>y a caterpillar. Boston 



Me, Heal an. I Sm-ieal Journal, 1901, CXLTV., 599. 



