1 



464 



THE BEGINNINGS OF LIFE. 



Vorticella embryos ^ The change generally takes place 

 in specimens which are already encysted^ and which 

 are lying side by side in a kind of tesselated peUicle 

 formed by closely-packed Euglen^. The early stages 

 of the transformation are precisely similar to those 

 which have been hitherto described. Decolourization 

 is gradually completed, till at last a whitish and very 

 finely-granular mass is produced^ spherical in shape^ 

 and enclosed within a rather thick cyst-walL These 

 bodies vary in size according to the dimensions of the 

 Euglense which undergo transformation^ and those which 



I have mentioned ranged from xoV-o'' ^^ -s-ro" ^^ ^^^*" 

 meter. They replace the Euglense^ so that they remain 

 as integral though metamorphosed parts of the coherent 

 tesselated layer. Very soon a vacuole makes its appear- 

 ance near the centre of the embryo^ v/hich subsequently 

 remains — disappearing only at short intervals. These 

 embryos^ unlike those of Paramecium^ do not rotate 

 w^ithin their cysts^ and do not seem to exhibit any 

 movements until they are about to become free. In 

 what precise manner they effect their exit I have 

 never been able to ascertain^ though I have several 

 times seen an embryo very shortly after its emer- 

 gence from its cyst (^). At this period they form 

 ellipsoidal masses of finely- granulated protoplasm, 

 generally containing one large vacuole^ and presenting 



^ Dr. Gros also distinctly states (p. 312) that Vorticellee may arise in 

 this manner — though he makes no express statement concerning a simi- 

 lar origin for other forms. 



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