60 REPORT ON DOURINE. 



and S. E. of the plaque was found to contain the trypanosoma in small 

 numbers, 4 to 5 in a cover- glass in each case respectively. On the 7th 

 day the plaque decreased in height and extended beyond the western 

 boundary. At each of the centres indicated the mature protozoa 

 increased in number from a minimum to a maximum, in one 

 instance from 5 to 5518 in a cover-glass, and then decreased, 

 finally disappearing, only leaving the developmental forms visible 

 on staining. During the extension of this plaque to the W. the 

 trypanosoma was also found in this situation and later passed 

 through the phases above described so that during the fifteen days 

 persistence of the plaque, different phases in the life-history of the 

 trypanosoma were observable on different dates within the area of 

 the same plaque. The changes which occurred in one portion 

 S. E. of this plaque may be briefly noted. 



First day. Tiypanosomata, long, thin, smaller than observed 

 in the mature protozoon, each present a single micro and macro- 

 nucleus. 



Second day. Increasing by longitudinal division in the usual 

 way. 



Third day. All forms present, some with single, others with 

 double micro and macro-nuclei. Individual organisms longer than 

 previously noted. 



Fourth day. 



(a) Single and double forms of micro and macro-nuclei. 



(b) Some swollen, much increased in size undergoing longi- 



tudinal division. 



(c) Tadpole shapes, ball (kugel), amoeboid and plasmodial 



developmental forms. 



(d) Trypanosomata in course of fading with large chromatin 



bodies. 



(<?) Many organisms exhibiting micro and macro-nuclei well 

 stained and at usual distance apart, but no protoplasm 

 of body visible, edges of refractile undulating mem- 

 branes can be detected, but they do not stain. 

 (/) Chromatin bodies free in the plasma stained, 

 5th day,' All forms and stages in the life-history of the proto- 

 zoon illustrated, many mature trypanosomata presented, well 



