660 SUMMARY OF CURRENT RESEARCHES RELATING TO 



definite time in water, provided it be constantly aerated ; food is not 

 necessary, though water-snails are appreciated. Owing to the transparent 

 integument, the parasites are visible in the living leech, and may be 

 observed in the stomach diverticula and intestine ; the cysts are found 

 in the same situation, but are especially numerous in the intestine. 



The Gregarines were obtained by making two incisions parallel to the 

 margins of the leech, and one at right angles to the long axis at about 

 the junction of the middle and anterior thirds. The gut contents were 

 then emptied into normal saline, from which the Gregarines were pipetted 

 on to slides for examination. Preparations in toto were made under a 

 cover-slip supported on wax feet, the various reagents being drawn 

 through with blotting-paper. The stains used were Grenacher's alcoholic 

 carmin solution and Schuberg's modification of Mayer's acid carmin. 

 Leeches destined for sections were fixed in Gilson's fluid. As stains, 

 Delafield's hematoxylin with eosin, safranin, and Heidenhain's iron- 

 hasmatoxylin were employed. To obtain the ripe spores, the cysts were 

 placed in a moist chamber, where the spores developed in 7 or 8 days. 

 The cysts were either placed on a slide in a drop of Neckar water, or 

 under a coverslip supported on wax feet. 



Observations on a Flagellate of the Genus Cercomonas.* — C. M. 

 Wenyon describes a Flagellate of the genus Cercomonas, which was found 

 in the fasces of a patient infected with Entamoeba coli. Cultivations 

 were made in hay infusion to which a small quantity of faeces was added. 

 Agar used for the culture of amoebae was also most useful. A film of 

 this medium was placed in a well formed by means of Czokor's wax, 

 arranged in ridges about \ in. high. The medium was inoculated with 

 material from a previous culture and a long cover-glass (1J in.) placed 

 on the well. By means of a hot wire and more wax the well is sealed 

 up. In this way the multiplication of the Flagellates is easily followed 

 with a Jv-in. objective, and if the film of the medium be sufficiently thin 

 with a T V _ in. 



For studying the Flagellates in the fixed and stained condition the 

 cover-glass method was mostly used. The best fixative was two-thirds 

 sublimate and one-third alcohol slightly acidified with acetic acid. Iron- 

 haematoxylin was the best stain. 



Simple Anaerobic Method. f — For this method, described by Crendi- 

 ropoulo, the only apparatus required consists of culture tubes, small 

 wide-necked flasks, and a hydrogen apparatus. Agar slopes are in- 

 oculated by Veillon's method. The platinum loop is introduced into 

 the condensation water and withdrawn carefully, so as not to touch the 

 surface of the medium. The tube is then inclined so as to distribute the 

 inoculated condensation water over the surface of the medium. Then a 

 half -turn allows the water to trickle back to the bottom of the tube. 

 Then, by means of a capillary pipette, the water is drawn off as com- 

 pletely as possible. The cotton-wool plug is flamed and pushed down 

 the tube to within a few millimetres of the top of the agar slope. A 

 tube from the hydrogen apparatus is introduced into the open end of the 



* Quart. Journ. Micr. Sci., lv. (1910) pp. 241-60 (19 figs.), 

 t Centralbl. Bakt., lte Abt. Orig., lv. (1910) pp. 247-8. 



