CHROMOPLASTS. 55 



the nucleus shows usually as a clear spot. The petals show 

 similar relations ; here the edges of the limb, as well as the 

 cilia (or fringe-like appendages) at the base of it, can be used 

 for observation in their entire thickness. The air adhering to 

 the limb hinders observation, but spots free from air will always 

 be found, or can be freed by light pressure. The sepals, how- 

 ever, are always preferable, since the papillae hinder observation 

 in the petals ; for it is evident that, with the exception of 

 the brown stripes on the two lower petals, each epidermal cell 

 of the upper and -under side is prolonged in its centre into 

 a blunt cone, one of the papillae in question. These papillae 

 are more strongly developed on the upper than on the under side 

 of the petals, and give to them a velvety appearance. The air 

 is entangled very strongly between them. The fiery-red spots 

 at the base of the petals are due to rosy cell-sap and yellow 

 granules in the epidermal cells. During the investigation it will 

 have been noticed that the surface of the epidermal cells of the 

 upper side of the sepals is longitudinally striate. The striae are 

 not interrupted at the limits of the individual cells, and are folds 

 of the cuticle which covers the epidermis. With watery solution 

 of iodine the colour-bodies can be fixed pretty well, and take on 

 at the same time a green coloration ; they are very sharply defined. 

 The nucleus is at the same time coloured yellowish-brown, its 

 nucleolus becoming very visible. With methyl violet, rosaniline 

 violet, or with gentian violet the colour-bodies are coloured violet. 



Similar chromatophores to those of the flowers of Tropceolum 

 can be found in autumn and winter in the coloured flesh of the 

 fruit of the hawthorn (Cratcegits), the hips of the rose, and the 

 berries of the asparagus ; while the comparatively large orange- 

 red chromatophores in the fruit of the tomato (Ly coper sicum 

 esculentum) show the form of chlorophyll bodies. 



If the large and beautiful flowers of Strelitzia regina. fre- 

 quently grown under glass in botanical gardens, are at our 

 disposal, opportunity of examining them should not be lost. In 

 the cells of the orange-red coloured perianth-segments will be 

 found elongated spindles of (for chromatophores) quite excep- 

 tional size, and which are, therefore, proportionally easy to 

 examine. 



Verbascum nigrum.- Yellow or orange-red colouring matter 

 is almost always combined with a protoplasmic basis ; but 

 isolated cases occur where it is met with dissolved. in the cell- 



