102 



FRANK R. LILLIE. 



The action of potassium chloride appears to be quite specific in 

 this respect, as was first discovered by Mead ('98), and since 

 described by Loeb ('01) and myself ('02). Such agents set in 

 motion the series of karyokinetic processes, which are then car- 

 ried through to their completion. But even violent mechanical 

 disturbances, such as are produced by shaking or centrifuging, 

 cause only temporary disturbances, and the equilibrium of the 

 mesophase of karyokinesis is soon reestablished. The methods 



. ' " ' : '*?* *iT.' '** ->'-7. -ut:' K&j?n *r-" 7 r ; '*** <** .-s BW* ->E*3 



g ^ ^li^l^^l P'fi? -V;7--- a 3 

 k ^SK3S^i^^^S ^AiTw^t;-- - --T 



&& t: ^ 'V- ; \ t &??> &&& ^.^ ^s*-'. >* J. :,A- -? 5w 



r ; -;:-^r ^i ? iMm^Cf xS : ' & ' m 



'Wa^SSl^^ 



N^V,^"*- '. - 'if :,y .'"{ ' -y / : .' .."" ''* p ' - 51 '. '-.'*hf' ' 



-'"'.'.,-' . .' " : ''. -I /''-'"'."/'"> ' * -'.'T 5 "~ 



V ,-,- "-..' . /. : .- _'*-*; ' **. '."" ."-.<, ' '. '-'<J.X 



FIG. I. Section of an egg of Chatopterus at the stage used for the experiments. 

 See text for description. I, karyokinetic figure; 2, central spongy area; 3, inner 

 dense zone ; 4, outer spongy area ; 5, ectoplasmic layer or outer dense zone. 



by which the regulation, or regeneration, of the karyokinetic 

 figure is brought about after centrifuging appear to me to have 

 some bearing on the problem of the nature of the dynamical com- 

 plex represented by the karyokinetic figure. 



Fig. i shows the typical condition of the eggs before centri- 

 fuging. The animal hemisphere contains a large karyokinetic 

 figure at the mesophase with nine chromosomes in the equatorial 



