A PRELIMINARY NOTE ON THE OCCURRENCE OF 

 A FILARIA IN THE CROW. 



J. H. ELLIOTT, M.B., 



LATE GEORGE BROWN MEMORIAL SCHOLAR, UNIVERSITY OF TORONTO, PHYSICIAN- 

 IN-CHARGE, MUSKOKA COTTAGE SANATORIUM, GRAVENHURST, ONT. 



The discovery of a number of species of filariae in birds in 

 southern Nigeria in 1900, when studying 'the haemamcebae, as a 

 member of the Liverpool Malaria Expedition to Nigeria, sug- 

 gested the question whether these parasites were to be found in 

 birds in temperate climates. 



Few opportunities offered in the course of my duties, but a few 

 bluejays and crows were secured during the summer of 1901. 

 The bluejays were examined with negative results. Of eleven 

 crows three were found to have embryo filariae in the blood, all 

 of one species. In two of the three the red corpuscles were in- 

 fected with Haltcridiuin. 



The search for the parent forms of the filariae was not success- 

 ful, and owing to the migration of the crows, further study had 

 to be deferred until the following summer. 



This year I have been able to secure only four crows. One 

 of these fortunately was infected with the same filaria found in 

 1901. After careful dissection and teasing of the tissues the pa- 

 rent forms were found in the coats of the pulmonary artery. In 

 appearance they resemble the human form F. Bancrofti. 



The embryos vary greatly in quantity in the blood stream of 

 the different birds. In the fresh preparation their movements are 

 rapid, and they progress readily in either direction. By ringing 

 with vaseline they will keep active for several days. The average 

 length of a number measured in the fresh preparation was 

 187.96 microns. In permanent cover-glass smears, dried, fixed 

 in alcohol, and then stained, the length varies somewhat, averaging 

 173.1 microns. 



What appears to be the head end is blunt or abruptly rounded, 

 the anterior two thirds being of uniform diameter. The posterior 



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