PART III.] Supplementary Details Relative to these Organisms. 635 



to be distinguished by the highest power which I possessed. At other times the 

 organism appeared to be closely applied to the corpuscle,, as though the latter were 

 being embraced by two short lateral pseudopods, and the outline of the corpuscle 

 appeared as if squeezed (Fig. 64, 6, c). At Fig. 64, d^ the corpuscle is shown with 

 the parasite immediately below it. No distinct flagellum could be detected extending 

 from the thicker portion of the parasite, though it was frequently observed to 

 present a ribbon-like appearance. 



Shortly after this the puppy got the " distemper," and was struck by one of the 

 native servants, so that it lost the sight of the right eye. On the 15th January, 1881, 

 several specimens of blood from its ear were examined, but not a single parasite 

 could be detected. Further examinations were made on the 12th and 28th February, 

 and again on the 24th March, but not a single specimen was found. The dates have 

 been carefully recorded, as they may be of use to future observers ; and the notes 

 of observations in this instance have been made to subserve the double object 

 of illustrating the more salient points in the microscopy of the parasite, and to 

 give the exact history of this form of parasitism in the dog during a period of 

 from four to five months. 



There are, however, a few other points in connection with the microscopy of 

 these organisms which it seems desirable to refer to as they may be of assistance 

 to systematic writers in deciding their precise position in the animal (or, as some 

 authorities may perhaps consider, vegetable) kingdom 



These supplementary details will be based on further observations which have 

 been made from time to time, as opportunities offered, during the last three or 

 four years, on the blood of rats, but more particularly on a series which were 

 conducted for purposes of comparison whilst the organisms in the dog were being 

 watched. 



On January 30th, 1881, the following entry is made in my note-book: Examined 

 the blood of five rats, aud found flagellated organisms in two of them. One of the 

 latter was a pregnant female, but this one, however, did not contain many specimens 

 of the parasite, and none were found in the blood of its young. The blood of the 

 other rat swarmed with the organisms. 



As it had been found that the parasites were remarkably well preserved in 

 a 0-75 per cent, solution of salt and water, half a Pravaz-syringeful of a mixture 

 of the blood of this rat, and of the salt solution — one part to three — was injected 

 into the sub-cutaneous tissue of the thigh of a healthy rat, free from blood 

 organisms, and which had been under observation for a fortnight. 



The animal did not appear to be materially affected by this procedure, and on 

 February 12th it is recorded: "The rat continues to enjoy excellent health; eats and 

 drinks freely. Not a trace of any organisms found in its blood, although the flagellated 

 organisms which had been introduced into its tissues were found to be alive two days 

 after the operation in what remained of the mixture which had been injected."' 



