THE BIOLOGY OF THE CELL 



Example 3.— The Proteus Animalcule {Amceba Sp.) 



Material. — Good specimens may usually be found by 

 scraping the slimy surfaces of water plants, washing 

 damp sphagnum moss, skimming the mud in the bot- 

 tom of ponds and ditches ; or raised artificially by keep- 

 ing such mud, together with decaying leaves, algae, 

 and other water plants, in a warm, dark place for a 

 few days. Such cultivations should be closely watched, 

 as Amaebm are likely to disappear rapidly in the course 

 of a few days after they are first found. A little fresh 

 water should be added to the cultivations from day to 

 day. If AmcehcB are to be kept in aquaria, be careful 

 to see that all snails are removed, otherwise they may 

 devour the specimens. 



The apparatus needed is the same as given for the 

 general study of Protozoa, with the following addi- 

 tions : camera-lucida, scale for measuring, dilute iodine, 

 one per cent, acetic acid, one per cent, acetic acid car- 

 mine, or fuchsin, powdered indigo or carmine, bristles, 

 warm-stage, alcohol lamp, glass rod, egg, and gum-arabic. 



Method of Examination. — The same as for Protozoa. 

 It is very likely that several drops of water may have 

 to be examined before specimens are found. In search- 

 ing for them, use the low power (f-inch or ^inch ob- 

 jective) ; then study with the higher power. Take up 

 a little of the sediment along with the drop of water 

 to be examined. Specimens of Amoeba may be kept in 

 good condition for several days in succession by placing 

 them in the moist chamber. 



Having found some good specimens, study carefully 

 the following : 



