in.] THE PROTEUS ANIMALCULE. 23 



8. Another form of Amoeba is not unfrequently found 

 which differs from that just described in being much 

 less coarsely granular, and in having no well-defined 

 ectosarc and endosarc, and also in having much 

 longer, more slender and pointed pseudopodia. 

 Another common form progresses rapidly with a 

 slug-like movement, only throwing out pseudopodia 

 at its anterior end. 



B. WHITE BLOOD-CORPUSCLES, (human). 



Prick your finger and press out a drop of blood : spread 

 out on a slide under a coverslip, avoiding pressure, and 

 surround the margin of the coverglass with oil. Neglect 

 the pale yellow homogeneous (red] corpuscles, and examine 

 the much less numerous, granular, colourless, ones. 



Note their 



1. Size: (measure). 



2. Form: changing much like that of the Amoeba, but 

 less actively. Draw at intervals of ten seconds. 



3. Structure: Some more and some less granular ; but 

 no distinct ectosarc, endosarc, and vacuole as in the 

 Amoeba. Nucleus rarely visible in the fresh state. 

 No contractile vesicle. 



4. Treat with dilute acetic acid : the granules are 

 cleared up, and a nucleus is brought into view in a 

 more or less central position. If the acetic acid has 

 been too strong the nucleus will be constricted and 

 otherwise distorted. 



5. Stain with magenta, and iodine; the whole becomes 

 coloured, the nucleus most intensely. 



6. Place on the hot stage, and gradually warm up to 

 50 C. The movements are at first rendered more 



