THE BEGINNINGS OF LIFE. 437 



favourable for higher changes. The contents of indivi- 

 dual Euglenae lose their distinctly corpuscular character, 

 and at last become obscured by a brownish granular 

 matter resulting from a decomposition of the chloro- 

 phyll. Meanwhile, a colourless outgrowth forms from 

 some portion of the surface of the vesicle, and gradually 

 increases in size (Fig. 84, c). This outgrowth varies much 

 in shape. It may be spheroidal or irregularly cylin- 

 drical, and is often more capacious than the Euglena 

 from which it is derived. The matter which it contains 

 is colourless, semi-fluid, and evidently derived from the 

 transformation of the substance of the Euglena — for as 

 the outgrowth increases in size, the Euglena gradually 

 disappears, till at last nothing of the old organism re- 

 mains except the thin investing membrane. The semi- 

 fluid contents of the outgrowth are not homogeneous : 

 from the first there exists, diffused through all parts of 

 it, a variable quantity of solid refractive matter, which 

 seems to be derived from a curdling of its semi-fluid 

 substance [d). This solid matter exists in the form of 

 irregular granules_, either separate or arranged in serial 

 aggregations variously uniting with one another. But 

 such irregularly disposed matter gradually aggregates 

 round definite centres, so as to form a number of solid, 

 refractive, nuclear spherules, pretty uniformly distri- 

 buted throughout the whole mass {e). After a time the 

 matter itself in which they are imbedded begins to 

 undergo segmentation, in such a way that each one 

 of the nuclear masses becomes included within an inde- 



