THE BEGINNINGS OF LIFE. 441 



normal contents of the Euglense had disappeared, whilst 

 their thin investing membrane was seen to be densely 

 packed with minute and now actively-swarming Monads, 

 some of which were still partly green in colour. On 

 the rupture of this membrane the liberated Monads 

 were observed to be almost spheroidal, minutely granu- 

 lar, and provided with a single flagellum 1. 



5. Resolution Into Diatoms. I have only distinctly 

 observed appearances indicative of this transformation 

 on one occasion j but in this case the whole of the con- 

 tents of a Euglena seemed to have been resolved into 

 seven distinctly-striated Naviculse (^). They were closely 

 packed within the thickened envelope of the Euglena, 

 which possessed no other contents save three or four 

 small refuse aggregations of reddish brown granules. 

 In close contact with this transformed Euglena there 

 was another of the same size in its natural green 

 state — so that the two might have been the products 

 of a previous fission. Although the earlier stages of 

 the transformation were not seen, I have no doubt that 

 the Diatoms originated in this way. A somewhat 

 similar mode of origin of some of the wedge-shaped 



* Dr. Gros refers (loc. cit., p. 323, PI. F, fig. 19 a, 6) to a somewhat 

 similar change which took place in specimens of Euglense which had 

 been kept for some time under the microscope ; and Mr. H. J. Carter 

 (' Ann. of Nat. Hist.' vol. xvii.) has also observed somewhat similar 

 changes. The internal contents of the Euglense became resolved into a 

 uniformly granular substance, which then segmented into six or eight 

 globular masses ; but on the rupture of the investing membrane, ' the 

 granular masses, being liberated, began to creep about under the forms 

 oi Actinophryi.^ 



