Protozoa ok simplest animals. 



19 



poJf/morphus, the Trumpet Polypus (Fig. 14), has a fuuuel-shaped High Wall 

 body of green colour, about ^V of an inch in length, and is usually Case 



E. end of 



to be found singly or in groups attached by the narrow end to Gallery 



organism changes its 



Fig. 15. 



duck-weed, sticks, &c. ; when swimming, the 

 shape considerably, becoming ovoid or 

 pear-shaped. The cilia are uniformly 

 distributed over the whole surface, but 

 form a spiral fringe of long cilia round 

 the anterior edge. See Plate XIIa., 2, 

 in the Case. 



Paranmcium aureUa, the Slipper 

 Animalcule (Plate XIIa., 1, in the 

 Case), has an oval flattened body with 

 cilia uniformly distributed over the 

 whole surface. Stylonydiia (Fig. 15) 

 has cilia only on the under surface of the 

 flattened body ; the thick spine-like organs 

 are peculiarly modified cilia by means of 

 which the organism can stalk about. 



ACINETAEIA. 



The body, in this group of Corticata, 

 is provided with tentacle-like organs in 

 place of cilia and flagella. Dendrosoma 

 radians (Plate XIII. in the Case) is a 

 fresh-water Infusorian of rather large 

 size, attaining a height of xV of an inch. 

 A fixed stolon gives rise to branching 

 trunks ; each branch terminates in 

 numerous suctorial knobbed tentacles, 

 which act by plunging into the bodies 

 of their prey and sucking up the protoplasm. In the young stage, 

 Dpiidrosoma is free and provided with cilia, which disappear when 

 the animal becomes fixed. 



Stylonydiia mylUu», the Mussel- 

 Animalcule. Magnified 150 

 diameters, a, nioutli; b, con- 

 tractile vacuole ; c, nucleus. 



