2o8 THE MICROSCOPE. 



Collecting and Preparing Infusoria. — Dr. H. Fol dis- 

 cusses this subject in a lengthy article and concludes that the most 

 valuable reagent is found in perchloride of iron. These subjects, 

 washed in alcohol and treated with gallic acid, present a brown 

 coloration, which is especially localized upon the nuclei, rendering 

 them very visible; the other parts of the animal acquire a light- 

 brown tint, which rendered them easy to see. They may be mounted 

 either in Canada balsam or glycerine. 



Mr. W. S. Kent has found potassic iodide almost identical in its 

 action to osmic acid and has the advantage of yielding no deleterious 

 exhalations. For preserving infusoria he uses the following ; To a 

 saturated solution of potassic iodide in distilled water, iodine is 

 added to saturation. The solution is then filtered and diluted to a 

 brown sherry color. A very small proportion only of the fluid is 

 added to that containing the infusoria. 



This October number is filled with matter of the highest value 

 to all interested in microscopy. The departments of zoology, 

 botany and microscopy are represented by one hundred and fifty 

 pages of solid type. The price is five shillings per number. 



NOTES ON HETEROPHRYS MYRIAPODA. 



BY DR. ALFRED C. STOKES. 



IT was with much pleasure that I recently noticed several indi- 

 ' viduals of the above named Rhizopod gliding about the meshes 

 of a net-work of alga; on the slide. The pretty little mass of 

 sarcode had previously come under my observation, but the in- 

 stances had been few and far between, and my notes on the subject 

 were scanty. Now, however, having accidentally captured the deli 

 cate creature in considerable numbers I hoped to compel it to an- 

 swer certain queries. 



The animal seems to vary much in size, those observed by Dr. 

 Leidy measuring from -g-^ to -^ inch, those among my own 

 gathering of algae ^-^ to -^ inch, including the external proto- 

 plasmic layer, the thickness of which in one case was 0.00075, m tne 

 other 0.0005 inch. With these latter individuals the micrometer 

 lines were brought across the Rhizopod after it had for some 

 moments been motionless, although it seldom comes to a complete 

 stand still. Yet as a rule its movements are slow; when it has failed 



