MICROriLARl^ FOUND IN THE BLOOD OF BIRDS. 59 



6. Some Microfilariae found in the Blood ol: Birds dviiig 

 in the Zoological Gardens, 1920-1921. By Rita 

 Markbreiter, B.Sc, R-esearch i^ssistant in the 

 Helminthological Department of the London School 

 of Tropical Medicine *. 



(Text-figui-es 1-6.) 



[Received November 6, 1922 : Read February 6, 1923.] 



From October 1920 till June 1921 the blood of 183 birds 

 which died in the Zoological Gardens of London was examined 

 and 22 were found to contain Microlilarise, roughly 12 per cent. 

 Of these 22 birds, one, a King Bird of Paradise [Cicinnurus 

 regius), contained two species of Microfilaria, and these two 

 species each occurred once again separately in other King Birds 

 of Paradise, so that in all 2'6 Microfilariae of 21 difiereut species 

 were found. 



The birds were of 21 species belonging to 15 difierent families, 

 and came from the following parts of the world : — Mexico, Brazil, 

 S. and TST. America, various parts of India, Chili, Java, Mada- 

 gascar, New Guinea, Malacca, and S. and W. Africa, which 

 siiows how wide the distribution of these parasites is. It is not 

 possible to name the embryo parasites unless the adults have 

 been simultaneously found ; in these cases they were only found 

 three times, namely : — (1) In the Mexican Hangnest {Oassicuhis 

 melanicterios), the adult being unidentified ; (2) in the Occipital 

 Blue- Pie (Urocissa occipitalis); and (3) in the Wandering Tree- 

 Pie [Dendrocitta vagahunda) : in both (2) and (3) the adult was a 

 Diplotriaena, and it is interesting to note that the corresponding 

 Microfilariae are of the same type though they difiei' in size. 



As in the Microtilarise of man, the avian Microfilarise fall into 

 two distinct types, sheathed and unsheathed, and in both groups 

 many different forms are found, long and short, thick and thin, 

 coiled and straight. Three of the Microfilarise listed were also 

 found by Plimmer, namely, the short form, occurring in Cicin- 

 nurus regucs, and those in Urocissa occipitalis and Cittocincla 

 macrtbra ; the others are reported for the first time. In the 

 detailed lists which are appended the adjectives short, medium 

 length, long and thin, medium thickness, and thick are repre- 

 sented by the following measurements : — Short = 0-100 /a ; 

 thin = under 3 fx; medium length = 100-200 /x; medium thick- 

 ness = 3-4 /x; long = over 200 /x ; thick = over 4/x. 



Reference. — Plimmer, "On the Blood Parasites found in Animals 

 in the Zoological Gardens," Proc. Zool. Soc, 1912. 



* Communicated by Prof. R. T. Leipeb, M.D., D.Sc, F.Z.S. 



