436 PEOr. ALLMAN ON THE RECENT EESEAECHES 



The thirty-two daughter cells irito which the egg-like cell has 

 thus broken up now begin to show amoeboid movements within 

 their common investing membrane. At the same time they emit 



Pig. 17. 



Magosphmra 'planula. 



A, unicellular encysted condition. B, the cyst containing two cells ; the 

 single cell divided into two by the first act of segmentation. 0, the contents of 

 the cyst divided into four cells by continued segmentation. D, the contents of the 

 cyst divided into sixteen cells by still further segmentation. E, the multicellular 

 sphere resulting from repeated segmentation has forsaken the cyst, and now 

 swims about by means of vibratile cilia. (Viewed from the surface.) F, the 

 ciliated sphere viewed in optical section through its centre, so that ten of its 

 component cells are seen in a meridional plane. G, an isolated ciliated cell with 

 long tail. H, the cell having lost its cilia and assumed an amoeboid form. 

 (After Haeckel.) 



