CLASS RHIZOPODA. 275 



and capable of being contracted into a spiral form. The 

 ciliated fringe can also be retracted within the body. 

 They multiply by fission, budding, and encysting. If 

 by fission, the body simply splits into two portions, each 

 becoming a new being.* If by budding, a swelling com- 

 mences near the base of the bell, which at length detaches 

 itself, and developing a stalk, becomes fixed. If by encysting, 

 a coating of gelatinous matter 

 covers the bell, the stem and 

 cilia being absorbed. In time, 

 the cyst bursting, a number of 

 germs are set free, which develop 

 stalks and become like the orig- 

 inal. It has been calculated that 

 the progeny of a single individual 

 of some species of Infusoria may 

 amount to two hundred million 



in a month. Noctiluca mUiaris, magnified. 



The Noctilucse are examples 



of free forms, in which locomotion is effected by thread-like 

 organs called flagella. The phosphorescent glow upon the 

 sea is largely due to their presence. 



CLASS RHIZOPODA. 



General Characteristics. The Khizopods (root-footed) 

 are minute masses of gelatinous matter capable of assuming 

 all varieties of shape according to the irritation result- 

 under the capita' of a column, lie there undisturbed ; but let a drop of water approach 

 it, and the dormant being awakes immediately, the microscopic Lazarus springs 

 again into existence, feeds and multiplies as before, and its life, suspended possibly 

 for years, resumes its interrupted course 1" 



* " By this mode of propagation," says Dujardin, " an Infusorian is the half of the 

 one which preceded it, the fourth of the parent of that, the eighth of its grand- 

 parent, and so on, if indeed we can apply the terms father or mother to an animal, 

 which must see in its two halves the grandfather himself, by a new division again, 

 living in his four parts. We might imagine such an Infusorian to be an aliquot 

 part of one like it, which had lived years, and even ages before, and which by 

 continued subdivisions into pairs might continue to live forever by its successive 

 development." 



