7()4 I)H. II. I!. KA.NTllA.M o\ TIIK [M:iy3, 



thduyii tlio si»or('S mv not .-leted on fxternally by the digestive 

 juices of tlie host. 



UninjuT'erl spoi-es of Gregarines have been ob.servefl by 

 L. Pfeitfei- in the alinientarv tract and fseces of various birds. 



APPENDIX. 



XoTK ON TltE GltorSK-FLV, Ol!\rill'iM)IA I.ACoroiUS. 



The I'elation of the gron.se-Hy, Oi-nlthonn/ia layopudls. to the 

 grouse has beei\ to some extent a nratter of conjecture. Though 

 tlie grouse-tlies often are found clinging to or concealed among 

 the feathers of the birds, the biology of the liy was uncertain, and 

 it was not known definitely whether the tlies obtained blood front 

 the grou.se or not. Having dissected several Innidreds of grouse- 

 Hies in an endeavour to find developmental stages of .some of tlie 

 Pi'otozoa infecting grouse, and po.ssibly parasites natural to the 

 tiy itself, 1 append the following notes on the insect, that may be 

 of interest. 



Kegarding the food of the gi-ouse-tiy, the insect sucks the 

 blood of the grouse. Blood in all stages of digestion has been 

 obtained from the gut of the iiy. Nucleated red cells of grouse 

 blood, wliich show no sign of digestion, are found in the red 

 fluid in the crops of recently fed Hies taken from grouse, while 

 on a few occ;isions leucocytes also have been observed. The 

 .stomach and particularly the inte.stine contain blood that is semi- 

 digested and consists almost entu-ely of cell nuclei. 



The blood, especially in the fore-part of the gut, has a peculiar 

 tint, and further, retains its fluidity for a very long time. Exani- 

 inati(jn of the salivary glands of the fly has shown that an 

 anti-coagulin is secreteil l)y them. I have tested the power of 

 this anti-coagulin in delaying the clotting of human blnod, u.siug 

 capillary tubes of blood and enudsion, and blowing out the contents 

 at intervals, controls being carefully kept. Blood mixed with 

 emulsion of the salivary glands required nine minutes for co- 

 agulation, while the controls, using salt solution, had clotted in 

 six minutes. The intestine of the fly also has anti-coagulin in it. 

 Another member of the Hippoho'^chhc, the sheep ked, Melnp/ni(/i(S 

 oviiiits, al.so secretes an anti-coagulin. The blood inge.sted by both 

 flies is prevented fi-om coagulating, and thereby is kept in a 

 more suitaV)le condition for digestion and ab.sorpticm by the fly. 



The peculiar colour of the blood in the foi-e part of the fly's 

 alimentary canal is apparently to be associated with some action 

 of the anti-coagulin, for an emidsion of the salivary glands of the 

 llv adile<l to luunan blood caused the latter to assume the same 

 peculiar hue as was noticed in the l)lo()d from the ci'op of the 

 grouse- fly. 



A fungus also infe.sts the Malpighian tubes of the fly. The 

 liyphal threads of the fungus rapidly develop rounde(l masses of 

 spores within sporangia. The sporangia coni[>lete!y lill the 



