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)een relea 

 )out for 



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'f Dr. Hassall ' 



:han 



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■at ion of tk 

 e is arrested, 

 lace the cor- 

 ', the contoor 



I 



nts a sensible 

 e decomposi- 

 2 The 



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rgans 



f once agaiD 



( 



tributes 



rtrea 



lination 



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1 



t 



k 



coin- 



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ee 



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 hours 



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Z^^ BEGINNINGS OF LIFE. 



177 



day. 



Dr. Hassall says : — ^ The tufts which I have 



gathered the day before^ and which presented no indi- 

 cation of the formation being near at hand, were in 

 general covered with spores the next morning; and 

 after midday these were all gathered on the surface 

 of the water beginning to germinate.' 



The mode of origin of the so-called ^ resting spore ' 

 or ^seed-cein^ in (Edogomum is also very interesting, 

 and illustrates in an important manner the question 



we are now considering. 



In this case^ the whole of 



the protoplasmic contents of one of the cells of the 

 plant goes to produce a single new reproductive ele- 

 ment, instead of many as in the case of Conferva 



Alexander Braun-^ describes the changes which 



£rea. 



take place as follows : — ^ In the formation of the rest- 



F 



ing seed-cells of CEdogonium we see the thickish cell- 



mucilage. 



contents composed of greenish coloured 



mixed with chlorophyll and starch vesicles, which, in 



the earlier vegetative period of the cell, form a lining 



^ These are reproductive products which do not develope., immedi- 

 ately after they have been formed, into the plant which they may ulti- 

 mately produce. They continue, as Braun says, * for a long time in a 

 condition of rest, during which, excepting as regards imperceptible 

 internal processes, they remain wholly unchanged/ The direct germ- 

 cells, or swarming-spores {gojzidia, or zoospores), however, pass on. 

 after their evolution, through a continuous process of growth and de- 

 velopment till the perfect plant is reproduced. These latter are the bodies 

 of which we have already spoken in connection with Conferva ^rea, and 

 of whose development in Achlya prolifera we are shortly about to speak. 



'^ ' Rejuvenescence in Nature ' (Translation by Henfrey, Ray Society), 

 1853, P- 164. 



VOL. I 



N 



