RHIZOPODS. 113 



ready been stated. But the mud is an accessible and 

 fruitful source of supply. 



To obtain them, gently scrape with a big iron spoon 

 or with the edge of a tin dipper, the surface of the 

 ooze from the mud in shallow ponds, and transfer it to 

 the collecting-bottle. Let the muddy mixtui-e stand 

 for a few minutes until the Rhizopods settle towards 

 the bottom, and carefully pour of some off the water, 

 addmg more ooze if desired. Pour the mud and water 

 into saucers, and set these near the window, when the 

 Rhizopods will make their way to the surface, and may 

 be removed by the dipping-tube. Do not place the 

 saucer iji the sunlight; Rhizopods prefer a little shade. 

 They are invisible, consequently the collector must 

 collect on faith, as he must usually do when out on a 

 microscopical fishing tour. But he will seldom be dis- 

 appointed if he gathers the surface ooze from the 

 edges of -somewhat shady ponds, and avoids those 

 places long exposed to the sun, and never sinks the 

 scraper into the thick black mud, which contains no 

 animal life of any kind. " 



They are small and easily overlooked in the field of 

 the microscope, but when one of the unprotected forms 

 and a single shell-bearing Rhizopod are recognized, 

 the observer will never again overlook any of them in 

 the material on his slide. The Amcxba will probably 

 be the first seen, as a colorless, jelly-like body, very 

 soft, and changeable in shape, slowly moving forward 

 and suddenly altering its course and extending itself in 

 numerous long, blunt, finger-like pseudopodia, which 

 are lengthened or shortened at the creature's will. 

 Or he may see a small pear-shaped collection of sand- 

 grains slowly moving about the slide, apparently with- 



9 



