VIEWS OP THE MICROSCOPIC WORLD. 



independent existences. Not only does this organism swim in a straight line 

 through the water, but it also proceeds on its course by rolling over and over side- 

 ways. It is frequently found congregated in vast numbers, clothing with a crimson 

 mantle the surfaces of ponds and stagnant waters. 



THE FLOWERING-CUP PROTOPHYTES. In figures 25 and 26 a singular structure is 

 exhibited, which appears in the shape of a branch ; formed of a series of cups 

 united to each other. 



The cup is nothing more than a delicate, pellucid shell, enclosing an organism 



which is attached to the bottom. The living 



Fig. 26. atom, with its encircling case, is distinctly seen Fig. 25. 



in figure 26. It is of a pale yellow tint, and is 

 furnished with a red eye-speck, the position of 

 which is indicated by the oval spot near one end 

 of the organism ; and far beyond the margin of 

 the shell protrudes a slender cilium. The flower- 

 ing-cup protophyte has the power of altering its 

 form, and at one time is seen contracting itself 

 into a round figure at the bottom of its cup, and 

 at another, extending its body as far as the 

 edge of its shell, which is its utmost limit. 

 These curious structures multiply by means of little cups, 

 which are seen budding from the parent-cup ; and thus it con- 

 tinues to increase, until at length a living branch is developed of 

 considerable size. In figure 25 such a cluster in seen containing 

 eight plantules, and the shells of three which have perished. 

 The motion of the vibrating cilia is indicated by the currents ; 

 and through the united and harmonious action of these strange 

 organs, the entire branch of motile organisms proceeds as one body through the 

 water. 



This protophyte is found in the water of swamps ; its length is about one-five 

 hundred and seventieth part of an inch, and that of a cluster one-one hundred and 

 twentieth of an inch. , 



D[ATOMACE,E OR DIATOMS. These photophytes, which are included by Ehren- 

 berg under the family of the Bacillaria; are invested, as already stated, with a 

 curious flinty envelope which constitutes their chief characteristic. This covering 

 is an object of great interest, not only for the elaborately-worked pattern, which it 

 often exhibits, but also for the perpetuation of the minutest details of that pattern 

 in the specimens obtained from fossilized deposits. The siliceous envelope of every 

 diatom consists of two valves or plates, usually of the most perfect symmetry, 

 closely applied to each other like the valves of a mussel. The form of the cavity 

 between the valves differs greatly, each valve being sometimes hemispherical, some- 

 times like a watch-glass, while in other diatoms they resemble boats, hearts, and so 

 forth. This curious class of vegetable existences are among the most beautiful of 

 microscopic objects. 



THE G-ALLIONELLA. This division of the Diatomacese has been termed G-allionella, 



