OSMOTIC GROWTH 



133 



Coralline growths may also be obtained by using appro- 

 priate chemical solutions. For this purpose the solution 

 of silicate, carbonate, and dibasic phosphate should he diluted 

 to half strength, with the addition of c 2 to i per cent, of a 

 concentrated solution of sodium sulphate or potassium nitrate. 



Corahlike forms may also be grown from a semi-saturated 

 solution of silicate, carbonate, and dibasic phosphate, to which 



FlG. 45. — An osmotic mushroom form. 



has been added 1 per cent, of a concentrated solution of 

 sodium sulphate or potassium nitrate. In this we may obtain 

 beautiful growths like madrepores or corals, formed by a 

 central nucleus from which radiate large leaves like (he petals 

 of a flower. The presence of nitrate of potassium produces 

 pointed leaves with thorn-like processes recalling the forms 

 of the aloe and the agave. 



Most remarkable fungus-like forms may he obtained by 

 commencing the growth in a concentrated solution, and then 



