150 MARTINI. 



ones in wliicli the liagellum Avas very short and the unduhiting nienihraiK! 

 poorly developed. These small forms (see Plate 1, fig. 6, a, and Plate 

 III, fig. 9) miglit suggest, on superficial examination, that they were 

 transition forms hetween the trypanosoma-like oi'ganism (already de- 

 scribed as lying in the red blood cells) and the fully developed trypano- 

 soma. Howexc]', these rudimentary forms were always found at the same 

 time as the well-developed ones. A chronological transition could not be 

 observed, in spite of critical observations made every hour. 



A careful study of stained preparations from the cultures showed a 

 remarkable fact. The parasites lying within the red blood cells, that 

 is, the piroplasmata already described, remained in the cultures until the 

 fifth day, apparently without having increased or decreased in mimber : 

 at the same time the trypanosomata showed an abundant multiplication 

 forming large rosettes. The latter were photographed, while living, in 

 a hanging drop preparation (see Plate V, fig. 19), in smear preparations 

 the large masses of the parasites were torn to pieces. While the multi- 

 plication of the trypanosomata occurred as mentioned above, no develop- 

 ment was noticed in the piroplasmata, although hourly observations were 

 made both during the day and for a portion of the night. One noticed 

 only a gradual swelling of the parasites and that the chromatin and 

 protoplasm stained badly, a phenomenon which went hand in hand with 

 the swelling of the erythrocytes. Finally on the fifth day nothing more 

 of the piroplasmata was to be seen. Transition forms between the 

 piroplasmata and trypanosomata were not observed either in the begin- 

 ning or in the later stages of the cultures. 



On about the third day of cultivation the trypanosomata were inclined 

 to assume involution forms; that is, to become somewhat thicker and 

 shorter and to lose their flagella. The chromatin became disintegrated 

 and stained badly; the blepharoplast small and like a point; yet the 

 outlines of the parasites were fairly distinct. Occasionally one had the 

 impression that a sexual increase had set in (see Plate V, fig. 26), forms 

 resembling spermatozoa apparently appearing in the cultures. However, 

 a careful study with the microscope immediately dispelled such an idea, 

 since these forms were seen to be merely involution forms of two trypano- 

 somata and their degenerated flagella. It is important to emphasize 

 that a development of piroplasmata into trypanosomata was, therefore, in 

 spite of the most careful study, not observed. At the same time a careful 

 examination of the fresh blood of the "original calf" for the presence of 

 trypanosomata was made. Smears of the blood were made every day and 

 on about ten occasions blood from the jugular vein was centrifugated 

 and smears from the surface examined. The result was always the 

 same; the ])iroplasmata were always present, ti'vpanosomata never. At 

 the same time the question of the pathological properties of the trypano- 

 soma for monkeys Avas studied. Three monkeys, Cynomolgus philip- 

 pinensis Geoffr., were given subcutaneous injections of 30 cubic centi- 



