1895 THE MICROSCOPE. 183 



Euplotes, Stylonychia and Halteria will also adhere to 

 these disks. Halteria is about the size of a white blood- 

 corpuscle, and the fact that it may be entrapped and 

 treated as here described shows what a wide range of 

 utility is. promised by this method. It will doubtless be 

 found useful in the study of minute eggs and larva?. 



I find that these disks may be mounted entire. One 

 in this way may get most instructive preparations, often 

 having a half dozen genera on a single slide. Staining 

 is also entirely under control ; any of the usual stains 

 may be employed and their action watched under the 

 microscope. With this method it has been found possible 

 to cut 18 longitudinal and 50 transverse serial sections of 

 Paramoecium with a thickness of 2.5 to 5 mm. with the 

 Ryder Microtome set to one or two teeth of the wheel. 



The fixation of the sections on the slide may be effected 

 by means of Gustav Mann's albumen method. Take the 

 white of an egg (30 c. c), shake up with 300 c. c. of water 

 for 5 minutes, filter twice. Paint clean slides on one side 

 with this mixture by the aid of a glass rod and stand 

 them on end to dry. The albumenized side of the dry 

 slides may be distinguished by breathing upon them. 

 The sections are stretched by floating the ribbon of para- 

 fine containing them on warm water (30 c). Immerse one 

 end of the albumenized slide in water and float and ar- 

 range the sections on it, albumemized side ujipermost. 

 Place the slide on a water bath to dry, when the paraffin 

 may be removed with xylol or turpentine, after which the 

 staining may be done on the slide. This method of fixing 

 sections with albumen is much simpler and more practical 

 than with Meyer's formula. 



The novelty and simplicity of this new method, as well 

 as its wide range of applicability will in many cases be 

 found to materially facilitate work, especially the work 

 of those engaged in the study of Protozoa, or of very 

 minute ova or larv?e. A very simple form of this ap- 



