OSMOTIC GROWTH 



I3i 



Fig. 40. — Osmotic growth in a solution of 

 KNO s , showing spine-like organs. 



chlorine, which may be found in the nutrient liquid after the 

 reaction. 



Of all the ordinary physi- 

 cal forces, osmotic pressure 

 and osmosis alone appear 

 lo possess this remarkable 

 power of organization and 

 morphogenesis. It is a 

 matter of surprise that this 

 peculiar faculty has hitherto 

 remained almost unsus- 

 pected. 



Osmotic Growths. — If we 

 sou fragments of calcium 

 chloride in solutions of the 

 alkaline carbonates, phos- 

 phates, or silicates, we obtain 

 a wonderful variety of lili- 



form and linear growths which may attain to a 

 .'50 or 40 centimetres Some are so flexible that the stems 



bend, falling in curves 

 around the centre of growth, 

 like leaves of grass. If we 

 dilute this same liquid, as it 

 becomes less concentrated 

 the growths are more curved, 

 ramified, dendritic, like 

 those of trees or corals. 



In the culture of osmotic 

 growths we may also bv 

 appropriate means produce 

 terminal organs resembling 

 flowers and seed-capsules. 

 To do this we wait till 

 the growth is considerably 

 advanced, and then add a 

 large quantity of liquid to the nutrient solution so as to 

 diminish the concentration a hundredfold or more. Spherical 



leiglit of 



FlG. 41. — Terminal organ', like catkins, 

 developing in a solution of ammonium 

 chloride. 



