34 ACTION OF AUXETICS AND KINETICS 



can be stained alive on a jelly, the coloured plate 

 showing the stages observed by this means. The 

 specimens can be fixed, but the stain appears to 

 fade from the nucleus more than from other parts 

 of the cell. Division of the body does not neces- 

 sarily follow division of the nucleus, and in this 

 way multinucleate forms may be produced. 

 Dividing amoebae placed on a jelly containing 

 alkali or on a firm jelly subjected to the pressure 

 of a cover-glass may be ruptured, and the free 

 nuclei retain the stage of division they were in 

 while within the cell, and can be readily stained to 

 show this. A multinucleate amoeba may divide 

 by binary fission into portions containing unequal 

 numbers of nuclei (fig. 11). 



Multiple Fission. This has been observed on 

 several occasions, and each time a multinucleate 

 amoeba was seen splitting up into from three to 

 five portions, each with usually a single nucleus. 

 This mode of division is particularly common on 

 media containing tyrosin. 



Budding has been seen once, four small amcebulas 

 being extruded in about half an hour (fig. 12). 



Conjugation 1 (PI. IX.) This takes place evi- 

 dently at rare intervals ; and as the forms in which 

 we observed it had been growing in augmented 

 auxetic for many days and consequently with 

 extreme rapidity of multiplication, it seems as if 

 conjugation occurs when the reproductive powers 

 of the organism have been called upon to their 

 utmost extent for some time. This fact has of 



1 We employ this term in a liberal sense as meaning the fusion of 

 two individuals which results in the production of a number of smaller 

 ones of the same species. 



