490 



SUMMARY OF CURRENT RESEARCHES RELATING TO 



organisms. To an ordinary glass slide are cemented pieces of glass 

 to form a box, open at the toj) and at jane end (fig. 83), the dimensions 

 of the box being 40 by 25 tjy 18 mm. ; the sides are lined with wet 

 filter-paper ; a cover-slip 25 by 40 mm., cleaned and sterilised, is placed 

 on the upper edges of the box, previously vaselined. On the under 

 surface of the cover is placed a drop of a nutrient fluid, and near to it a 

 drop of culture containing the organisms to be isolated ; the whole is 

 then placed on a Microscope stage ; a fine capillary pipette with a curved 

 tip and a brass holder is clamped to the left side of the stage : the box, 

 with its open end towards the pipette, is adjusted so that the cross 

 lines [x] on the cover are in the centre of the field ; the pipette is then 



Fig. 83. 



adjusted by moving it in the groove at the side of g, and by turning the 

 screw s that moves the parts r and g of the holder, until the point is 

 nearly in the centre of the field ; the pipette, with the parts g, Ic, and n 

 holding it, is raised or lowered by the screw /, the part v being clamped 

 to the Microscope stage. 



The portion of the cover bearing the sterile drop of medium is now 

 brought into the field : the tip of the pipette is then raised into it and 

 partially filled ; the pipette is then lowered and the culture-drop is 

 brought into the field ; the pipette is then again raised until it comes 

 into contact with the micro-organism to be isolated ; this at once enters 

 the pipette (often in company with other cells) ; the cover is then 

 moved by the mechanical stage, until the tip of the pipette can be 

 brought into contact with an unoccupied part of the cover, when its 

 contents are discharged, Ijeing blown out gently by means of the rubber 

 tube t. The author suggests various modifications to be used in special 

 conditions. 



Cultivation of Amoeba of Dysentery.* — A. Lesage has found that 

 human dysentery amoebae, either in the soft or cystic stages, when 



* C.R. Soc. Biol. Paris, Ixii. (1907) p. 1157-9. 



