60 PSYCHE [June 



The Screw Worm {Chrysomyia macellaria). In the Western Medical Review 

 for December, 1907, Dr. Henry B. Ward, under the title "Nebraska Case of the 

 Screw Worm" gives the following interesting account of the habits of the larva of 

 this fly. "Through the great courtesy of Dr. H. Winnett Orr of Lincoln, I have 

 received recently a number of insect larvae which were taken from the nasal fossse 

 of a patient. There were in all a very large number of these larvae, probably up- 

 wards of two hundred, although only a few were saved. Their numbers and the 

 extensive destruction of the tissues which took place during their growth in the host 

 brought the trouble rapidly to a fatal termination in spite of all that could be done. 

 The case was so unusual for Nebraska, and its outcome so serious that an exact 

 determination of the species of insect and of its habits seemed imperatively demanded." 



The species is found throughout South America and a large portion of North 

 America, especially in the tropical and subtropical regions. It is often very injurious 

 to domestic animals. A small wound when infested, becoming a large and dangerous 

 ulceration. In man they usually infest the nasal fossse, depositing its eggs in the 

 nostril "to which it is usually attracted by a fetid catarrh. The larvae grow rapidly 

 reaching maturity in five to eight days." 



"Of treatment, Manson (Trop. Dis., 4 ed. 787) says: 'If treated properly and 

 in time by injections of chloroform, carbolic acid, turpentine, infusion pyrethorum 

 and similar substances, the patient may be saved: neglected he will most probably 

 die.' In any event the mortality is large among these cases. Thus Laboulbene 

 lists 15 cases of which 9 were fatal; among the 31 cases collected by Maillard, 21 

 died. Both of these authors deal with records from South and Central America. 

 In the United States I have found 55 to 60 cases published; in 31 a definite record 

 was given as to course of the disease and its results, and in 22 of these the outcome 

 was fatal." In the Jour. A. M. A. Dec. 7, Yount and Sudler report 23 cases from 

 Arizona and New INIexico in 1905, only four of which were fatal. 



Owing to its wide distribution and variation some 27 specific names have been 

 applied to this species. On the Atlantic coast the species is common as far north as 

 New Jersey. Numerous specimens were taken on a dead shark at Truro, INIass., 

 Sept. 4, 1904, and at Squantum, Mass., Oct. 9, 1905, by ]SIr. A. P. Morse. It has 

 frequently been taken by Mr. Owen Bryant at Cohasset, Mass., in August. Mr. S. 

 A. Shaw has found a specimen at Hampton, N. H., and the writer obtained a 

 single specimen on a window of the Boston Society of Natural History, August 19, 

 1903. 



C. W. Johnson. 



