STEUCTURE AND LIFE-HISTOEY OF CRITHIDTA MELOPHAGIA. 217 



liquid at stated times and noting when coagulation occurred 

 in each. Typical results of these experiments are tabulated 

 below : 



A. Adult Melophagus. 



Coagulation period Coagulation period 



Obviously an anti-coagulin was present, for considerable 

 delay of clotting occurred. 



B. Young Melophagus. — Here the interval between the 

 clotting of the test and control preparations was noted. A 

 few typical results are given : 



(1) Blood Tnixed with emulsion of the salivary glands 

 clotted nine minutes after the control. 



(2) Emulsions of intestine added to blood caused the latter 

 to take three times as long to clot as the control preparations 

 took. 



Comparing the behaviour of the emulsions of the salivary 

 glands of young and of older keds, the anti-coagulin seems to 

 be more strongly developed in the salivary glands of the 

 older keds, while a similar comparison between the intestinal 

 emulsions would tend to show that the anti-coag-ulin was 

 more abundant in the intestines of young keds. 



The temperature at which the anti-coagulin was destroyed 

 was also investigated. It was found that below 50° C. the 

 anti-coagulin would act. At about 55° C. its action was 

 checked. When 60° C. was reached it was destroved. 



Human blood mixed with emulsions of any part of the 

 alimentary canal at once assumed the vivid red hue so notice- 

 able in the blood removed from the gut of the keds. 



The red blood-corpuscles of the sheep, seen en masse, 

 appear far brighter on adding emulsions of the gut of the 

 ked containing the anti-coagulin. When much water was 

 added to normal blood, haemolysis occurred, and the colour 



