viii. B. 6 Boynton: Rinderpest Blood in Water Leech 517 



fed on infected blood on January 22, forty days previously, were 

 disintegrated in a mortar in salt solution. The mixture of blood 

 and salt solution was injected subcutaneously into bull 3547. 

 One of the leeches was dead, 1 was inactive, and 2 were in nonnal 

 condition at the time they were put in the mortar. The animal 

 apparently suffered no ill effects from the injection. It was 

 proved by a subsequent inoculation to be susceptible to rinderpest. 



Experiment 27. — On February 6, 1913, two liters of water 

 were given by drench to bull 3547. Twelve leeches that had 

 fed on infected blood fifteen days previously had been kept in 

 this water. This animal suffered no ill effects from the drench. 

 It was proved susceptible to rinderpest by a subsequent inocula- 

 tion of virulent blood. 



Experiment 28. — On February 8, 1913, three leeches were 

 allowed to feed for fifteen minutes on cow 3546, during the third 

 day of temperature of an attack of rinderpest, and were trans- 

 ferred to water for one hour. They were then placed on sus- 

 ceptible animal 3548, and allowed to become engorged. Cow 

 3548 suffered no ill effects from the biting of these leeches. 

 She was proved susceptible to rinderpest by a subsequent in- 

 oculation of virulent blood. 



Experiment 29. — On February 8, 1913, three leeches were 

 allowed to feed for fifteen minutes on cow 3546, on the third 

 day of temperature of an attack of rinderpest, and then trans- 

 ferred, without being placed in water, to susceptible cow 3549. 

 The interval between the two feedings was twenty minutes. 

 Animal 3549 suffered no ill effects from this feeding. It was 

 proved susceptible to rinderpest at a later date by an inoculation 

 of virulent blood. 



On March 4, 1913, eleven leeches were allowed to feed for 

 thirty minutes on cow 3564, on the fourth day of febrile tem- 

 perature of an attack of rinderpest, after which they were 

 tranferred to water in a cool place. The infectiveness of the 

 blood in these leeches was determined by testing upon cattle at 

 various periods subsequently, as shown in experiment 30. 



Experiment 30. — On March 10, 1913, the 11 leeches which had 

 fed on cow 3564, on March 4, six days previously, were allowed 

 to feed on cow 3570 until they become engorged. This animal 

 apparently suffered no ill effects from the feeding. She was later 

 proved to be susceptible to rinderpest. 



Since the animals used in experiments 6 and 7 had been found 

 to be infected with surra, it was thought best to test leeches for 

 their ability to keep the trypanosome of surra alive in ingested 



