214 



PROCEEDINGS OF THE ACADEMY OF 



[1896. 



Chromoplasts include all colored chromatophores, not green. It 

 may be seen from this that the distinction is quite an arbitrary one. 

 Chromoplasts may originate from leucoplasts or chloroplasts. This 

 latter case can be easily observed in the ripening of many fruits, 

 as they change from green to red, for example, apples or the berries 

 of the potato plant. 



As indicated by the variety of colors found in plants we have to 

 deal with a number of chemically different substances. The litera- 

 ture existing on these pigments is not very satisfactory. Although 

 the metamorphosis of the chloroplasts into the chromoplasts may be 

 readily observed the new substances resulting from this metamor- 

 phosis are not well known. This past summer I became somewhat 

 interested in the red color of fruits and collecting among others those 

 of Ilex verticillata, I found that they turn brown in 50 per cent 

 alcohol, those of Gaultheria procumbens turn gray ; those of Magno- 

 lia glauca, dark brown ; those of Lindera Benzoin, almost black ; 

 those of Berberis Thunbergii, light brown ; those of Cratcegus cocci- 

 vea, dark brown. It is a matter of general observation that in most 

 cases when immersed in alcohol the red color disappears and changes 

 to gray, black or intermediate tints and this no doubt is due to a 

 process of oxidation of the pigment. In rare instances, however, the 

 red color does not seem to be affected by alcohol as, for examples, the 

 berry of Arisoeyna triphyllum and the aril of the seed of Celastrus 

 smndens. The latter I determined to submit to microscopical and 

 chemical examination and the following are the results of my 

 observations. 



The coloring matter in this case occurs in chromatophores. The 

 figure reveals the following anatomical structure : — A very much 



thickened cuticle (c) of a lemon yellow 

 color. This without a doubt affects to 

 some extent the tint of the aril which 

 has some yellow in it. Courchet' states 

 that the color of certain fruits is entirely 

 due to the impregnation of pigment in 

 such epidermal thickenings and he cites 

 as illustrations Solatium macrocarpum 

 and S. racemiflorum. Tiie epidermis (e) 

 consists of a layer of smaller cells of a 

 rather uniform size. The chromato- 



^ Courchet. Recherches sur les chromoleucites, Annales de Sc. Nat., Bot. 

 VII, Ser. VII, 1888, p. 301. 



