506 ON THE DEVELOPMENT OF DERMATOBIA HOMINIS. 



cannot hesitate to pronounce them identical. Similarly the inner skin of this larva 

 agrees perfectly with that of the largest larva described second, so that no one can 

 doubt of their identity. Thus the larva from the toucan is proved to be of the same 

 species as that from man, and another host has been added to the list of those in which 

 this Dermatobia parasitizes. At the same time two successive stages in the develop- 

 ment of the Dermatobia hominis have been positively identified. There remain now 

 to consider critically the other American cases of this parasite and to determine pre- 

 cisely, if possible, the relation of these larvae to other well-described specimens. 



V. OTHER CASES RECORDED IN THE UNITED STATES. 



i. Historical and Critical. — The earliest reference in American writings to the 

 species under consideration was made by Say ('22), who had received a specimen 

 extracted from the leg of a Dr. Brick during a journey in South America. Say's 

 description of the larva is faulty in that he regarded the anterior end as posterior 

 and vice versa, but otherwise it is very satisfactory and permits one to assert with some 

 confidence that his specimen was identical with the smallest larva described in this 

 paper, or the stage designated by Blanchard as ver macaque. The size given by 

 Say has been wrongly quoted by some authors; it was 14 milhmetres long by 3.8 

 millimetres broad. The specimen was deposited in the cabinet of the Philadelphia 

 Academy of Natural Sciences, but is not now in existence, according to information 

 kindly furnished by the curator. 



The description quoted by Say from a letter gives an interesting clinical history 

 of the case, especially valuable on account of the observer's profession. Dr. Brick 

 was stung by some insect while bathing and the larva was extracted after about six 

 weeks. It gave rise to excruciating pain at intervals, owing, as he inferred even before 

 the determination of the cause, to "something alive beneath the skin." It was at first 

 " a considerable tumefaction over the tibia, which had the appearance of an ordinary 

 bile (Phlegmon); in the centre there was a small black speck." The tumor began 

 to discharge at about four weeks, and was so serious that he was "scarcely able to 

 walk." Scarifying the tumor yielded no results, and finally poulticing with cigar- 

 ashes and rum for five days resulted in the extraction of the larva dead. Dr. Brick 

 records that "it had travelled on the periosteum along the tibia for at least two inches." 

 While later authors hold very generally that the larva always inhabits a fixed spot in 

 the subcutaneous tissues, I do not find that any one has referred to this record of 

 migration made by a most competent observer. 



