THE BEGINNINGS OF LIFE. 209 



much inherent vigour to lose their own individuality a 

 supposition which was confirmed by their great increase 

 in size and subsequent development. On the fourth 

 and fifth days many were seen which had grown out 

 into minute filaments, resembling what is commonly 

 regarded as Leptothrix^ although they also possessed all 

 the characteristics of a miniature fungus-mycelium. 



Thus, then, we may have modified areas in which 

 the contained units flourish and grow, whilst still pre- 

 serving their own individuality; or we may have pel- 

 lucid areas persisting as such for a certain time, whose 

 units at last undergo a process of molecular fusion and 

 regeneration, leading to the production of a segmenting 

 embryonal area from which brown fungus-germs are 

 produced l . And, lastly, there may be pellucid areas 

 which, almost as soon as they are formed, begin to 

 undergo those changes whereby they are converted into 

 true embryonal areas. 



1 During this process the contained Bacteria disappear, and a whitish 

 refractive and homogeneous protoplasm is produced in the place of the 

 jelly and its contained granules. If we turn to the account given of the 

 origin of the ' germinal membrane ' in the ova of higher animals, we 

 may be struck by the similarity of the phenomena. Miiller says (Baly's 

 Translation, vol. i. p. 9) : ' It appears, indeed, that the germinal mem- 

 brane is formed by the attraction and aggregation of the globules of the 

 yolk ; but all parts developed in this germinal membrane are produced 

 by solution of these globules, and conversion of them into a matter in 

 which no elementary particles can be distinctly recognised, and of which 

 the molecules must at any rate be beyond comparison more minute 

 than the globules of the yolk and germinal membrane.' The subse- 

 quent development of plastodermic cells from this mass also agrees closely 

 with what occurs in our embryonal areas. (See vol. i. p. 211, note 2.) 

 VOL. II. P 



