170 A. A. C. ELIOT MERLIN ON THE ROUSSELET LIVE-BOX. 



I have had the live-box, thus modified, in use for a consider- 

 able period, have employed it in the critical examination of the 

 smallest living forms under oil immersion objectives, and have 

 found it possible to keep them under observation for several 

 days ; while with the live-box of the ordinary construction the 

 water-film usually completely dries up within twenty-four hours. 



With the Rousselet live-box an oil immersion objective may be 

 employed without any fear of the oil mixing with the water in 

 which the organisms exist ; and, if necessary, the immersion 

 objective may be changed, and the oil wiped from the cover, 

 without seriously disturbing or injuring the living contents. 



The large air-space within the contrivance is generally sufficient 

 to keep the organisms active and healthy for some considerable 

 time ; but it is not suggested that the conditions are favourable 

 for their development, or for the study of their life-histories; 

 for such purposes the Dallinger Stage, and other descriptions of 

 growing slides admitting plenty of fresh air, would, doubtless, be 

 found preferable. 



Journ. Quekett Microscopical Club, Ser. 2, Vol. IX., No. 56, April 1905. 



