THE PARASITIC PROTOZOA OF THE RED GROUSE 331 



intestine, contain blood that is semi-digested, and consists almost entirely 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. Examination of the salivary glands of the 

 fly has shown that an anti-coagulin is secreted by them. I have tested the power 

 of this anti-coagulin in delaying the clotting of human blood, using capillary tubes 

 of blood and emulsion, and blowing out the contents at intervals, controls being 

 carefully kept. Blood mixed with emulsion of the salivary glands required nine 

 minutes for coagulation, 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 Hippoboscidce, the sheep-ked, Melophagus ovinus, also secretes an anti- 

 coagulin (Porter, 1910). The blood ingested by both flies is prevented from 

 coagulating, and thereby is kept in a more suitable condition for digestion and 

 absorption by the fly. 



The peculiar colour of the blood in the fore-part of the fly's alimentary canal is 

 apparently to be associated with some action of the anti-coagulin, for an emulsion of 

 the salivary glands of the fly added to human blood caused the latter to assume 

 the same peculiar hue as was noticed in the blood from the crop of the Grouse-fly. 



A fungus also infests the Malpighian tubes of the fly. The hyphal threads of 

 the fungus rapidly develop rounded masses of spores within sporangia. The 

 sporangia completely fill the Malpighian tubes, the spores finally bursting out as 

 rounded bodies into the lumen of the gut, and thence pass outside the host. 

 Melophagus ovinus contains a similar fungus (see Porter, 1910). 



In connection with the fungus, which is common in the Grouse-flies, I may 

 say that I have never found flagellates present where the fungus existed, and a 

 similar condition obtains in the sheep-ked Melophagus ovinus. 



The Grouse-fly examined as a possible vector of the protozoal parasites of the 

 Grouse yielded rather poor results. However, I have found protozoal vermicules, 

 some without melanin, others doubtfully with a little, in the gut of the fly. These 

 might be stages (ookinetes ?) in the life-history of Leucocytozoon lovati or Hcemo- 

 proteus mansoni, or of both. There is also the possibility of Ornithomyia lagopodis 

 being the transmitter of Spirochceta lagopodis, though I am inclined to suspect 

 Ixodes ricinus here, but the whole question of the transmission of the protozoal 

 parasites of Grouse is one demanding much more material and very careful 

 investigation. 



I also kept a number of the pupae of the Grouse-fly for further investigation, but 



