Ernest Warren 
305 
(4) The intensity of the purple colouration over the general outer surface 
of the ordinary flower. 
(5) The ratio of the maximum width of the corolla at the mouth to the total 
length of the corolla, expressed j^^^^^ x 1000. 
With reference to the spotting on the inside of the flower the percentage area 
covered by the spots was estimated by the help of a diagram consisting of a series 
of equal sized rectangles each of which was spotted to a known extent : 4 %, 8 %, 
12%, 16%, 64%. 
For estimating the intensity of the purple colouration over the general outer 
surface a colour scale was obtained in the following way. Avery weak solution* 
of a mixture of aniline dyes was prepared which resembled the purple colour of 
the flowers. This solution was placed in upright rectangular glass jars of varying 
internal dimensions. With transmitted light the intensity of colour, of coiirse, 
varied according to the depth of fluid. Jars of internal dimensions, measured 
from back to front, of 20 mm., 30 mm., 40 mm., 50 mm., 60 mm., 70 mm., 80 mm., 
90 mm., 100 mm., 140 mm., 280 mm., were employed, and the colour of the solu- 
tion, as viewed from the front of the jar with light coming from behind, was com- 
pared with the general colour of the flowers. Thus, if the colour of the flower was 
nearest, say, to the colour of the solution in a jar with a thickness of fluid of 70 mm. 
the colour of the plant was said to be 70. For a comparatively small range, as 
from 20 to 100 mm., the method appeared to work satisfactorily, but less reliance 
can be placed on the greater depths. In any case a scale of some definite physical 
significance is obtained. 
The colour of the flowers is due to the presence of a purple cell-sap. In the 
case of the general colouration of the whole surface both the outside and the inside 
epidermal ceUs bear this coloured sap. In the spots, where the colouration is much 
more intense, the coloured cells are confined to the epidermis on the inside of the 
flower. In flowers which are white, with the exception of the deeply coloured 
spots, there may be some exceedingly faint traces of isolated streaks of purple on 
the inside of the flower, these are due to a slight colouration of the inside epidermal 
cells. 
The flowers were measured with compasses and scale. The width was the 
maximum distance between the reflexed margins of the mouth, measured from 
right to left, and the length, measured along the adcauline surface, was the distance 
from the middle of the straightened- out margin of the mouth to the middle of the 
insertion- edge of the corolla. 
1. The peloric Character. 
The peloric flower at the top of the axis would appear to arise by the fusion of 
a varying number of the uppermost flowers and the concurrent entire suppression 
of the internodes between such flowers. Usually the apex of the main axis is un- 
* Water 100 c.c, rubin 2-375 mg., gentian violet 0-125 nig. (Griibler). 
