404 THE BEGINNINGS OF LIFE. 



central portion becomes resolved into thousands of 

 active Bacteria. 



5. At other times, whilst the external portions of the 

 embryonal sphere break up into myriads of embryo 

 Bacteria, the central portion escapes this change and 

 becomes transformed into a Fungus-sporangium about 

 3oW in diameter, sometimes like g and sometimes 

 like g or g' , 



6. Very rarely it happens that, after complete de- 

 colourization, the whole mass becomes more plastic 

 and finely granular, and creeps about in the form of 

 a large vacuolated Amoeba (Fig. 80, ^), which under- 

 goes rapid changes of shape, and may subsequently 

 assume the form of an Actinophrys (^). 



7. Or the whole mass having become colourless and 

 highly refractive, it assumes a slightly ovoid form, 

 gradually becomes more animal ized in its composition, 

 pushes cilia from its surface, and thus becomes bodily 

 converted into an embryo of one or other of the various 

 forms of Ciliated Infusoria (^r r', d /). At other times 

 (as in the case of the transformation into Monads) 

 the mass may undergo change within a very delicate 

 cyst formed by the condensed outer layer of the 

 spheroid. The cyst ultimately gives way near one 

 of its extremities, so as to permit the exit of a young 

 Oxytricha — an infusorial form which is almost in- 

 variably to be found within dead though still closed 

 internodes of Nitella^ 



' Further details concerning the origin of Oxytricha (pp. 467-469) 

 and other Ciliated Infusoria will be found in the next Chapter. 



