446 EVENINGS AT THE MICROSCOPE 



of others of much smaller dimensions, and of a drop-like 

 form, so set as to radiate round the principal vesicle as a 

 centre, the rounded portion of each in apparent contact 

 with the vesicle; and the slender extremity running off 

 as an attenuated point till lost to sight in the sarcode. 

 The main vesicles alternately become distended, and sud- 

 denly contract to a point; while the radiating cells are 

 continually varying in size, though in a less degree. It 

 is customary to describe the secondary vesicles as coming 

 into view at the instant of the contraction of the primary 

 one, and to suppose that the emptying of the one is the 

 filling of the other; but I have not been able to observe 



PARAMCECIUM. 



this mutual relation satisfactorily made out. The smaller 

 as well as the larger vesicles are conspicuous from their 

 colorless transparency; for the general sarcode of the body, 

 though pellucid, is only so in the same degree as glass, 

 slightly smoked; besides that its clearness is often im- 

 paired by crowds of granules and minute globules. 



You ask what is that comparatively large oval body 

 attached by its side to one of the leaves of the plant. It 

 is the egg of some considerable Kotifer, probably Euchla- 

 nis, which is always glued to some filament or stem of 

 a water-plant. It may interest you to watch the progress 

 of the contained embryo, which you can readily do, since 

 the egg-shell is as transparent as glass, and the infant ani- 

 mal already displays the movements of independent life. 



