THE BEGINNINGS OF LIFE. 497 



as a very diminished representative of its Oxytricha- 

 progenitor. All the stages of this very interesting 

 transformation are minutely described by M. Haime l 

 in his memoir, and have also been very carefully de- 

 lineated in numerous figures and to these we must 

 refer the reader who wishes for further particulars. 



We may state, however., that Mr. H. J. Carter 2 

 seems to have witnessed somewhat similar changes, 

 by which specimens of Kerona pustulata 3 , after encyst- 

 ment, gave rise to Plxsconia Charon a form closely 

 allied to Trichoda lynceus. Mr. Carter hesitates about 

 accepting such a conclusion because he did not actually 

 see the specimens of Plasconia Charon issue from the 

 previously-observed cysts j and therefore with excessive 

 caution though for reasons which do not now carry 

 much weight he thinks that they may not have done 

 so, and rather inexcusably suggests that M. Haime may 

 also have made some mistake. Yet Mr. Carter had 

 put numerous specimens of encysted Kerona aside in 

 three separate watch-glasses, and in each of these 

 receptacles, at about the same time that the embryos 

 within some of the cysts began to show signs of 

 activity, he noticed the presence of empty cysts and 

 also that specimens of Pltesccnia were to be seen 

 swimming about in the watch-glasses. As not a single 

 active Kerona could be detected, the specimens of 



1 ' Ann. des Sc. Nat.' 1853 (Zoologie), PI. 6. 

 * 'Ann. of Nat. Hist.' 1859, PP- 2 5 T ~ 2 55' 

 3 See p. 243, note i. 

 VOL. II. K k 



