69 



order this condilion. ;i rnpid recovery lakes jjhice. It is 

 known how (hiricull il is to hi'inj* al)()ut a change. n;diirally 

 within certain lindts, in llie osmotic pressure. hy(h'(),i»en 

 ion concentration in the juice of the intact organism, ilie 

 disturbance has to attain a certain order of inagnituck' Ijcfore 

 the condition is altered and it takes then onh' a relatively 

 short time to restore the balance. The tissue cells are res- 

 ponsible for the stationary condition in the body; the cata- 

 bolic substances are eliminated, and the changes caused by 

 the interactions of the colloidal systems i. e. the tendency to 

 decrease the relative surface of the disperse phase, are 

 prevented and do not come to a true physico-chemical termi- 

 nal-equilibrium. The interval between this terminal-equili- 

 brium and the stationary condition within the organism, 

 might be called the kinetic of the juices. Perhaps the kinetics 

 of the embryonic tissue juice have a much wider range than 

 the body juices of the adult. 



^^hen we now consider the life of the tissues in vitro 

 and make a comparison with that of the tissue cells in 

 vivo, we have no elimination of the end-products in the 

 culture. When we allow the cells to grow in the same culture 

 medium for a long time, accumulation of calabolic substan- 

 ces causes the death lof the cells after a certain length of 

 time, when the body juices from the adult alone represent 

 the culture medium. By adding tissue juice from the embryo 

 to the culture medium the cells may be rendered able to 

 live much longer in the same medium before they die, and 

 the cause for this difference may be the different range ol 

 kinetics in the embryonic tissue juice and the plasma from 

 the adult. In other words, the buffer action, if we may 

 call it so, of the embryonic tissue juice is far greater than 

 that of the adults and probably it is in the buffer action 

 or kinetic range, that we may find the cause of the growth 

 promoting power. 



That life ])rocessess are influenced and dependant upon 

 physico-chemical forces is beautifully demonstrated by J. 



