yello^ and then disappear, dissolving slowly. With Millon's reagent, at 

 first cold, then gently heated, no definite reaction takes place. With 

 sodiTMn coralline, aniline blue .tincture of Alkanna, Sudan III, and cyanine, 

 they do Act stain. With 1 per cent osmic acid, they turn black almost in- 

 stantly, and, following this treatment, they show an evident resistance to 

 the solvent action of water and dissolve less readily in alcohol. With 

 ammonium, potassium, and sodium carbonate, and with potash and ammonia, they 

 become yellow. With ferric acetate and with ferric chloride, they become 

 blackish blue. With bichromate of potash in concentrated solution, they 

 stain reddish brown. Methylene blue in aqueous solution they absorb in a 

 short time. (15 ) . 



The complexity of the reactions above brought out is not such as to 

 lead one to any safe conclusions as to the nature of the substances which 

 constitute the involucre of the cyanoplast. On the other hand, one may 

 concliode that they do not belong to proteinaceous substances. Moreover, 

 the reactions obtained through the use of ferric salts, potassiun bichromate, 

 alkali, alkaline carbonate, sx\&. methylene blue show that a chromogen of 

 tannic nature is present in this involucre. But, since, following the 

 transformation of the tannin in the anthocyanine, the involucre does not 

 disappear but rather is rendered the more evident, there follows the deduction 

 ^hat in its formation it may contribute to the substances which contribute to 

 its s.tllI.tm]£nowti constitution. 



Development ^ At the stage in which the corolla begins to emerge from 

 the calyx cup, if one examines the epidermis (ventral and dorsal) and the 

 parenchyma at the margins of the azure blue petals, one will be able to find 

 all the stages of the development of the cyanoplasts. They appear at first 

 as very minute spherical bodies scarcely visible, colorless or pale blue^ 

 (Pl- XVII, fig- 1)^ immersed in the cytoplasm, without showing any proper 

 moi 



