55 



quantity of eosine in solution was injected in a similar manner into 

 the aural vein of a second rabbit, the subjects of inoculated Surra, 

 during concurrent paroxysms in each animal respectively. Later, 

 blood was drawn from each animal and mixed and the fresh blood 

 submitted to microscopical examination, in order to determine the 

 results of conjugation if possible. In the few examples which 

 came under observation, no coloured particles were seen to leave the 

 body cavity of one and enter that of the second haematozoou . 

 Further, the micro-nuclei were not observed to fuse or to alter their 

 relative positions, one to the other, in conjugating organisms. 



II. Mode of entry and subsequent generalization of the or* 

 ganism. An equine, stallion or mare, usually contracts the disease 

 during the act of coition. The trypanosoma or its developmental 

 forms are present in the semen of the affected male, and are also 

 frequently present for long periods, but at irregular intervals in the 

 vaginal mucus of the affected mare. The disease is transmitted by 

 the entrance of the trypanosoma, by means of an erosion of the genital 

 mucous-membrane in either sex, but an abrasion may perhaps be 

 unnecessary in some instances. In the stallion the preferential sites 

 for the development of the protozoon appear to be the extremity of 

 the penis and later its sheath. In the mare, the vulva appears 

 to be the usual seat in the majority of cases. Certain changes 

 probably take place at the seat of inoculation of the contagium, 

 for it is unusual for the organism to enter the circulation and 

 bring about a general infection as evidenced by the eruption of 

 cutaneous plaques, until a period of 80 to 34 days have elapsed, 

 from the date of the primary infection. On the other hand, it is 

 not at all uncommon for an inordinate period 10 to 12 months or 

 longer to occur, before any blood infection takes place in stallions, 

 especially if the first symptom of swelling of the sheath is observed, 

 and the animal is immediately segregated, has complete rest, 

 good food, and covering is discontinued. The exact date of cover- 

 ing the infected mare which communicated the disease to the stal- 

 lion, may have been recognized, and no subsequent chance of contract- 

 ing the disease may have been allowed so that it is possible to 

 accurately fix the date of onset. Although the " materies morbi " 

 of the disease is present in a localized region of the animal, the 



