THE CONSERVATION OF LIFE 



227 



appearance still the same, yet differing from what it was before. 

 The whole process of conjugation, which mostly begins in the 

 early hours of the morning, lasted about twelve hours, 



But the process is still incomplete, and is continued in the 

 separated animalcules until a complete renovation of the entire 

 nuclear apparatus has taken place. The first step towards this 



FIG. 56. CONJUGATION OF PARAM^CIUM IN SIX STAGES. 



(1) Two slipper animalcules, 'mouth to mouth': the micro-nucleus of the 

 individual on the right begins to divide ; (2) division of the micro-nuclei in both 

 individuals is complete, and the parts are about to divide again ; (3) in each of the 

 conjugating individuals four daughter-nuclei have been formed ; (4) three of these 

 in each individual perish, the fourth divides again into two nuclei, which are 

 described as ' male ' (shown as black or white) and ' female ' (striped) nuclei ; (5) 

 exchange of the two 'male' nuclei; (6) separated, male and female nuclei have 

 become fused into one conjugation-nucleus, from which a new macro-nucleus and 

 micro-nucleus originates, while the old macro-nucleus disintegrates. 



end is that the ' male ' and ' female ' nucleus fuse into one. 

 Then the old macronucleus disintegrates with every sign of 

 degeneration ; we may see its remains lie for some time in the 

 cell-body until they have gradually been eaten up. But from the 

 conjugation-nucleus a new macronucleus and a new micro- 

 nucleus originate by fission, and thus the animalcules are ready 



