﻿344 



The Philippine Journal of Science 



1914 



Two dissecting needles may be employed by the use of the 

 two pipette holders. The second holder may be clamped to an 

 elongated plate screwed to the stage of the microscope (fig. 

 15) or to any firm support apart from the microscope. In 

 order to bring both points into the moist chamber, a bend in one 

 of the capillaries may be necessary. I have used an isolating 

 chamber with a side opening, so that the second pipette holder 

 could be clamped on the front of the stage. However, it was 



Fig. 15. Microscope with two pipette holders, each containing a pipette attached to the stage 

 by means of metal plates. Seen from the back. A, a three movement, and B, a two move- 

 ment holder ; (/, adjustment, governed by screw s", for moving the pipette to and from the 

 observer. The other letters correspond to those shown in Figs. 1 and 2. 



found difficult to keep the isolating chamber moist with two 

 openings in it without using a special closing device, so the 

 position first described is preferred. 



With both holders provided with three movements, one has at 

 command two dissecting needles, with rigid points as fine as 

 the end of a colon bacillus, each of them movable in all directions 

 of space. In addition, it is possible to move the organism in 

 two directions by means of the mechanical stage. Dissection 

 may be carried on under the oil immersion, and either needle may 

 be transformed into a pipette at will. The wall of Spirogyra 

 may be opened and the nucleus removed, microscopical animals 



