Poisonous Arthropods 



40. Same as figure 39, on larger scale. 



through some curious mis- 

 understanding Goeldi (1913) 

 has featured the larva of 

 Orgyia leucostigma, the white- 

 marked tussock moth, as the 

 most important of the poi- 

 sonous caterpillars of this 

 country. Though there are 

 occasional reports of irritation 

 from its hairs such cases are 

 rare and there is no evidence 

 that there is any poison pres- 

 ent. Indeed, subcutaneous 

 implantation of the hairs 



leads to no poisoning, but merely to temporary irritation. 



Occasionally, the hairs of certain species of caterpillars find lodge- 



ment in the conjunctiva, cornea, or iris of the eye of man and give 



rise to the condition known as opthalmia nodosa. The essential 



feature of this trouble is a nodular conjunctivitis which simulates 



tuberculosis of the conjunctiva and hence has been called pseudo- 



tubercular. It may be distinguished microscopically by the presence 



of the hairs. 



Numerous cases of opthalmia nodosa are on record. Of those 



from this country, one of the most interesting is reported by de 



Schweinitz and 



Shumway (1904). It 



is that of a child of 



fifteen years whose 



eye had become in- 



flamed owing to the 



presence of some for- 



eign body. Down- 



ward and inward on 



the bulbar conjunc- 



tiva were a number 



of flattened, grayish- 



yellow nodules, be- 



tween which was a 



marked congestion of 



the conjunctival and 



4L 



eye f a chM ' 



