630 



SUMMARY OF CUKRENT RESEARCHES RELATING TO 



holder is mounted on an endless screw forming a diameter of the disk I, 

 and supported by two flanges J, J\ at each extremity. This screw is 

 operated by the milled heads H and H^ and displaces the object-holder, 



Fig. 91. 



and centres the desired part under the objective. It is found that the 

 head of the pin being out of focus does not interfere with the optical 



image. 



Fig. 91 shows the insectoscope mounted on a binocular. 



(6) Miscellaneous. 



Quekett Microscopical Club.— The 492nd Ordinary Meeting was 

 held on October 28, the President, Prof. A Dendy, F.E.S., in the Chair. 



S. 0. Akeburst exhibited and described a changer for use with sub- 

 stage condensers. This was on the principle of the Zeiss sliding objec- 

 tive changers. 



S. C. Akehurst exhibited and described " A Trap for Free-swimming 

 Organisms." This was a device for taking advantage of the photo- 

 tropism displayed by most pond-animals. 



