- 5- 



If one uses a solution of potassium iodide, oni will note that it 

 acts so slowly on the cyanoplast that it is possihle to follow with the 

 microscope the various phases of its dissolution. The action of the reagent 

 'oecomes manifest with the yellowing of the mass of the cyanoplast within 

 which there appears one or more cavities. With progress of the action of 

 the reagent, these latter will increase in size and terminate in a manner 

 which results in the development of a great vacuole bounded by a dense wall 

 which later dissolves and disappears. 



If one uses the same reagent containing some drops of hydrochloric 

 acid, the cyanoplasts stain red and shine on the yellow background of the 

 protoplasm in a manner which enables one to follow, even better, the above- 

 alluded-to phases of their dissolution. 



These reactions and others which I have been able to make with dilute 

 alcohol, with very dilute alkali, and especially with neutral salt solutions 

 serve to show the independence of the two substances which constitute the 

 cyanoplast. 



Nevertheless, as will subsequently be shown, there are those instances 

 in which the c^ranoplasts appear to be colorless, namely, depriveitof said 

 pigment, and, in such cases, we are able to investigate microchemically as 

 to the chemical nature of their involucre and of the substances contained 



within it. • 



Such colorless cyanoplasts are of homogeneous structure, oily appear- 

 ance, and possess high retractility. They show the following reactions: 



In water, at ordinary temperature, they vacuolize and end by dissolv- 

 ing con?)letely. The-jdissolve a^ickly in absolute alcohol or in alcohol 

 diluted to 50 or 75 per cent, and likewise in ether, in chloroform, in 1 per 

 cent hydrochloric acid, in very dilute alkali, in neutral salt solutions, 

 and, finally, in glycerine. With a solution of potassium iodide they stain 



