64 EEPOIIT ON DOURINE. 



forms of the organism, each presenting 1 one micro and macro- 

 nucleus, respectively. On the 39th day the mature trypanosoma. 

 was observed for the first time ; in addition, the immature forms 

 were present. 



40th day. No mature organisms, only immature forms present. 



4ht day. Trypanosoma again present. 



42nd to 46th day. Mature organisms absent. 



48th to 75th day.'No mature trypanosoma discovered. 



The period of incubation was a prolonged one the first imma- 

 ture form being only observed on the 19ch day, while the mature 

 trypanosoma was not discovered, until the 89th day. Several 

 paroxysms with intermissions varying in length followed, and 

 finally during a period of 27 days no more mature parasites were 

 found. The " materies morbi" of the disease entered the blood 

 between the 27th and 32nd days following the experimental in- 

 oculation. This latter fact confirms the statement already made 

 with regard to date on which the eruption of plaques in horses 

 takes place, viz., 24th to 34th days, but more frequently between 

 the 30th and 33rd days after covering or experimental inoculation. 



XI. The blood from the general circulation of an animal, the 

 subject of Dourine, does not exhibit at all periods of the malady 

 the snme power of reproducing the disease in susceptible animals. 

 Except during the height, of the eruption of plaques it is unusual 

 during the course of Dourine, to find on microscopical examination, 

 the mature trypanosoma in the blood of the general circulation. 

 In some animals the numbers of cutaneous plaques are compara- 

 tively few, appearing singly after long periods of intermission. In 

 others they are very numerous, several appearing daily or every 

 other day ; this eruption is continued for a period of several weeks' 

 duration. In the one instance, it is difficult and at times impos- 

 sible in a susceptible animal, unless a relatively large amount of 

 blood is utilized, to reproduce the disease by subcutaneous inocula- 

 tion, witk blood collected half-way through the period of a 

 prolonged intermission. In the other instance, in an animal 

 where the plaques are numerous, when one or more of them 

 are in constant process of change, and their contents are being 

 frequently voided into the general circulation, the inoculation of 



