ON THE DEVELOPMENT OF DERMATOBIA HOMINIS. 507 



Say quotes the description of Gmelin and definitely assigns this specimen to 

 (Estrus hominis. He asserts positively its distinct character, especially as against 

 CE. bovis, to which some would refer it, and points out clearly its differences from other 

 species of the genus, while inclining to refer it to the recently established genus Cuterebra 

 which Clark had formed at the expense of the older genus CEstrus. 



The second observation recorded in the United States is that of Penniston ('44). 

 The larva was removed from a sailor in the Charity Hospital at New Orleans, who 

 had acquired it in a trip to the provinces of Vera Cruz and Tabasco, Mexico. The 

 larva is not now in existence. It measured 21 millimetres in length and 8.4 milli- 

 metres in maximum width. From the figures as well as from the careful description 

 given by the author it can be recognized as a Dermatobia larva in a late stage of 

 development. The mammellated elevations, ten to twelve on each segment, into 

 which each was divided indicate an older larva than the second stage described in 

 this paper. It was not old enough, however, to undergo metamorphosis when removed 

 from the arm of the host, though it remained alive four days. Penniston regarded 

 the form as certainly an CEstrus and asserts, after " comparing it with the imperfect 

 description hitherto given of the larva of the (Estrus found in the human body, that 

 several varieties of this insect have already been observed, and that this constitutes 

 another perfectly distinct." It is, however, evidently a well-developed larva of the 

 stage designated by Blanchard as torcel. Penniston's paper was reprinted in French 

 as part of another contribution (Coquerel et Salle, '59). 



The case recorded by Verrill ('72) was cited by Blanchard as one the specific 

 character of which could not be definitely determined. The citation is incorrect, 

 in that the paper noted by Blanchard (Verrill, '70) makes only bare mention of the 

 occurrence in Central and South America of such a parasite , and the review cited deals 

 with another paper by the same author in the same volume and does not include any 

 reference of any sort to this form. In a later paper, however, Verrill refers ('72, p. 342) 

 to the earlier report, and cites a "similar case in the United States" which afflicted 

 a young woman of Meridian, Miss. "The larva?, developed from eggs deposited in 

 the skin by the fly, caused great irritation and pain in the subcutaneous tissues, result- 

 ing in large abscesses, from which the mature larvae finally escaped." As Verrill 

 examined some of the larvaB one may infer from absence of remarks that they cer- 

 tainly did not possess the striking form of Dermatobia Iarva3; the description also 

 corresponds well to other forms, and does not seem to belong to the species under 

 consideration, so that I unhesitatingly strike it from the list of cases of Dermatobia. 

 In 1887 Matas reported the case of an Englishman from Spanish Honduras upon 



