HOLMAN'S SYPHON SLIDE. 197 



or animalcule-cage, fig. 136, for the purpose of study- 

 ing the growth of fungi and other delicate organisms, 

 without in any way disturbing them for a lengthened 

 period. This will also be found useful as a dry 

 chamber for holding minute insects, and preserving 

 them in a living condition for observation. 



Zentmayer's Holman Syphon Slide (fig. 137) is used 

 either as a hot or cold water cell. It should be deep 

 enough to hold a small fish or newt, and retain it with- 

 out any undue pressure. When in use it is only necessary 



FIG. 137. Hotmail's Syphon Slide. 



to place the animal into the groove with some water, 

 cover it with the glass cover, and immerse one of the 

 rubber tubes in a jar of water, the other receiving it as 

 it passes away. When the slide is on the stage of the 

 microscope the jars should stand on a lower level, so 

 that the slide be made the highest part of the syphon. 

 The pressure of the atmosphere is sufficient to keep 

 the cover-glass in its place. This apparatus is also 

 adapted for the gas microscope. 



The examination of various kinds of infusorial life 

 be greatly facilitated by the addition of the small- 



