19 



ZOOLOGY. 



In swimming, tlie monad stretches out the wliip-lasli-like 

 appendage called tlie f!(if/eJIiini, which vibrates with an nn- 

 dulating, whirling motion, ami ])roduces 

 a peculiar graceful rolling motion of 

 the monad. When the monad is fixed 

 the flagellnm is nsed to convey food to the 

 month, which lies between the base of 

 the flagellnm and beak, or "lip."' The 

 food is tlu'own b}' a sudden jerk, and with 

 precision, directly against the month. 

 "If acceptable for food, the flagellnm 

 presses its base down npon the morsel, 

 and at tlie same time the lip is thrown 

 back so as to disclose the mouth, and 

 then bent over the particle as it sinks 

 ^'?he7ihSaV"yiari into the latter. When the lip has ob- 

 ^rstatel'vithZ'S: taincd a fair hold upon the food, the 

 omThead"""ok£ flagellnm withdraws from its incumbent 

 o, anterior end; h, position and returns to its former rigid, 



hinder part of the ' 6 ' 



body; c, iiuch'us. ^vatcliful Condition. The process of de- 



Highlj- magnified. , ,■,■ • ,, • i i ,- 1 i 



ghitition IS then earned on by tne help 

 of the lip alinie, wliieli cxjiands latterly until it completely 

 overlies the particle. All tliis is done quite rap- 

 idly, in a few seeomls, ami then the food glides 

 q'I quickly into the deptlis of tlie liody, and is envel- 

 oped in a digestive vacuole, whilst the lip assumes 

 its usual conical shape and ]ii'opoitions. " (Clark.) 

 Fre 8-U- Some momids arc attached by a slender stalk to 

 fl''"tiiate '-''^ leaves and stems of aquatic jilants, and these 



infusori- are usuallv collected into comiionnd monads Sev- 

 an, or . . ■ ' 

 monad, cral arising Irom a. common st;ilk. In such cases 



^vith two ,, ,, -iT-i 1 1, 



large ci- the liody With its nucleus and two or three con- 

 fiag'Sia': tractile vesicles is snrinounted bv a delicate collar 



Greatly - - - ' ' 



ni a g n 1- 

 fied." 



out of which the lash (flagellnm) iirojcets. 

 Jlonads multiidy (1) either by self-division, or('^) 

 by the production of great nuinljcrs of e.xtremolv minute 

 acrms. Hence the minutest of all beings reproduce from 



