308 SUMMARY OF CURRENT RESEARCHES RELATING TO 



Cultivation of Plasmodium vivax.* — P. I. Pitschugin, after a 

 review of the work of Bass and Johns, Gurko and Hamburger, and 

 others, upon the artificial culture of the malarial parasites, give an 

 account of their own experiments with Plasmodium vivax. The tech- 

 nique followed was that of Bass. 10 com. of blood withdrawn from 

 the ulnar vein of a patient were put into a sterile cylinder containing 

 0*1 c.cm. of a 50 p.c. dextrose solution. The blood was defibrinated 

 by stirring with a glass rod and put into an incubator at 40° C. Films 

 were prepared and examined at intervals. These films were fixed with 

 methyl-alcohol, and stained with Argutinski's methylen-blue eosin 

 method. By means of these procedures the authors observed two 

 complete, and a third incomplete, cycle of development of the parasites. 

 In the third generation, only schizonts and merozoites were found. The 

 addition of inactivated ascitic fluid or of dextrose solution in greater 

 quantity than that stated above, does not have any influence on the 

 growth of the organism. In the preparation of films for observation 

 the authors recommend that some of the clear supernatant fluid be 

 sucked up, so that thin films may be obtained. 



Isolation of Single Trypanosomes.t— F. Henningfeld describes his 

 method of separating individual trypanosomes for the purpose of micro- 

 scopical observation and inoculation. First he used a modification of 

 Lindner's method, which consists essentially in the mounting of a series 

 of minute droplets of diluted suspension of organisms on a slide. He 

 found, however, that the capillary pipette method was better. Measure- 

 ment showed the pipettes used had a lumen of about 0-018 mm. in 

 diameter. The glass wall was 0"00G mm. in thickness. Trypanosome- 

 infected blood w 7 as diluted with broth, saline, or serum — the latter was 

 the most satisfactory — and drawn into the pipette. A portion of the 

 pipette about 7 cm. in length was placed on a slide and examined in 

 detail with a compensating ocular Zeiss 12, and an objective of medium 

 power. The ends of the pipette were sealed with wax. If a parasite 

 was found lying in isolation the margins of the zone containing it were 

 marked with a Leitz object marker. Then, while the portion containing 

 the parasite was held in position with a superposed slide, the remainder 

 of the capillary-tube was cut away with a knife. By this means 

 individual parasites were obtained for observation and inoculation. 

 Successful inoculations with mice of single specimens of Trypanosoma 

 bracei and T. equiperdum were accomplished. 



Single Cell Cultures.^— M. A. Barber describes his method of 

 making a series of cultures from single cells. A large cover-glass 

 (38 x 65 mm.) is carefully cleaned, sterilized, and placed on an isolation 

 chamber. Cross lines are ruled on its upper surface. By means of a 

 bent pipette, droplets of sterile broth, 2 mm. in diameter, are placed in 

 rows on the under surface. Two larger drops are put towards the ends 

 of the cover. By means of a pipette a small portion of actively growing 



* Centralbl. Bakt., lte Abt. Orig., lxxiii. (1914) pp. 373-84. 

 t Centralbl. Bakt., lte Abt. Orig., lxxiii. (1914) pp. 228-39. 

 % Philippine Journ. Sci., Sect. B, viii. (1913) pp. 539-57. 



