HOWARD AND HOWARD. 25 



the width of the lobes of the leaves is au important distinction 

 between types 4 and 5. 



There are also differences in the texture of the leaves. Types 

 1, 2, 7 and 8 have coarse thick leaves with a puckered surface, 

 while the leaves of type 4 are very thin and flat. Thin leaves 

 are also met with in types 3 and 5. 



Colour. The most striking differences in these types are 

 colour differences. Not only is both red and purple found, but 

 the localisation of the colour varies in a very interesting manner. 

 From the natural crosses it appears that the red colour is domi- 

 nant but is diluted in the Fj generation. Many pink stemmed 

 plants have been selected, all of which split into purple stennned, 

 green stemmed and pink stemmed plants in the next genera- 

 tion. 



In type 4 the colour of the leaf is a dark bronze green with a 

 tendency for purple patches to appear as the leaf gets old. The 

 corolla shows a purple eye and much purple colour diffused on the 

 petals especially at the back. The capsules also show a good deal 

 of purple colour. In the whole plant the chloi'ophyll is masked 

 and the general appearance is purple. 



In type 5 the purple colouration is not so intense. The lobes 

 of the leaves are entirely green and are broader than in type 4. 

 The plants are shorter and more robust and the flowers earlier. 

 The general appearance is that of a purple plant with green leaves. 

 It will be seen in Plate III that the colour in type 3 is red rather 

 than purple and that this colour only reaches to within 6 oi' 7 inches 

 of the apex. This occurs both on the main stem and on the side 

 branches. 



Transverse sections show that the colour in the purple varie- 

 ties is due to a crimson coloured cell sap which fills the entire epi- 

 dermal layer and also the outer layers of the cortex. On mounting 

 a section in water the cell sap of some of the epidermal cells readily 

 diffuses out, turns blue and temporarily stains the collenchyma 

 which lies beneath the chlorophyll-containing cortex. In type 3 

 the cells with colovired sap lie scattered in the outer layers of the 



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