274 University of California Publications in Zoology [Vol. 16 



very hea^•y. ilultinucleate forms are found which may divide by 

 plasmotomy. Small "young" forms are figured and these gi-ow into 

 the large ones. Schardinger has figured what looks like an endogenous 

 bud but he says nothing about it. 



The cyst, 14-16fi in diameter, has a double, contoured wall in which 

 there are from three to six thickenings which look like pores of a pollen 

 grain. The cytoplasm is granular. The nucleus from Schardinger 's 

 figures may or may not have the chromatin broken up. He found one, 

 two, and four nuclei ; in the last case the cyst was 24/t in diameter. 



The flagellate behavior of Schardinger 's species agrees with that 

 of the species of this paper, in time required for enflagellation, in 

 reaction to stimuli, in number and position of flagella. position of con- 

 tractile vacuole, character of cytoplasm, and modification of form. 

 Schardinger figures the nucleus of the flagellate as having rather 

 evident peripheral chromatin in every case, while in my form it may 

 or may not have it. Also he figures an occasional mononucleate 

 flagellate with three and four flagella. The nucleus, he says, is alwaj^s 

 close to the base of the flagella but he was unable to demonstrate a 

 connection between the two organelles. 



In so far as the life-cycle in certain other forms is knowna it agrees 

 very nearly with some of those just mentioned, as for example Glaser 's 

 (1912a) division stages of Anioeha tachypodia, obtained from pond 

 water, but for which a flagellate stage has not been found. 



However, Wherry (1913) described a form obtained from the water- 

 supply of Oakland, California, which becomes a flagellate and which 

 agrees, so far as he went, in every respect with the one upon which I 

 have worked, except in the matter of amitosis which has not been 

 found by me. The latter he says he has watched, but he does not 

 describe or figure it. It may well have been mitosis which he saw*. 

 He describes the characters of the amoeba but does not figure division 

 stages, except plasmotomie cytoplasmic division. He figures three and 

 four coincident spindles, multinucleate forms, endogenous buds, a 

 flagellate with a contractile vacuole and two equal flagella, but he does 

 not figure these showing any rhizoplast or other connection with the 

 nucleus. He figures a cyst with a double wall, in the inner one of 

 which are five "markings" or pores. The size of the cyst is 9.2/n to 

 39.6/t, generally uninucleate, but .sometimes with from one to eight 

 nuclei. 



From these facts it follows that the species worked on by Schar- 

 dinger (1899), that worked on by Wherry (1913) and the one described 



