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r^y^ BEGINNINGS OF LIFE 



217 



jective made it easy to recognise such transitions as 

 are depicted in Fig. ^']. As in the instances previously 

 recorded, the first appreciable stage in the formation 

 of an embryonal area in the pellicle was a local in- 

 crease in the amount of gelatinous material between 

 the units of this portion of the pellicle, which thus 

 became more distinctly separated from one another 

 than in adjacent parts. Gradually these particles be- 

 came less sharply defined, and at last scarcely visible, 

 in the midst of a highly refractive protoplasmic mass 

 which began to exhibit traces of segmentation. 



Masses of this kind were seen, which had been re- 

 solved by such a process of segmentation into a number 

 of spherical corpuscles about 



4 500 



in diameter. These 



presence 



became rather less so, and revealed the 



two or three minute granules in their interior. 



were at first highly refractive, though they gradually 



of 

 In 



other adjacent areas, a number of densely packed, 

 pliant, and slightly larger corpuscles were seen actively 

 pushing against one another. When they separated 

 they were found to be active ovoid specimens of Monas 

 lens about -^i—' in length, and provided with a vacu- 

 ole and a rapidly-lashing flagellum. On the fourth 

 day the number of embryonal areas throughout the 



pellicle had 



increased, and the 



specimens 



Monas 



existed in myriads in the infusion. They were 

 tolerably uniform in size, though some were notably 

 smaller than the average, owing to the fact that they 

 were products of a recent fission, all the stages of which 



