30 
James Small. 
relation to insects all authorities are agreed that blue is the highest 
colour. The order of efficiency in attracting desirable insect-visitors 
may he taken as more or less established and beginning with green 
goes upwards through yellow to orange, white, pink, red, purple, 
violet and blue. Green, yellow, orange and white may be taken as 
the primitive group, and red, purple, violet and blue as advanced. 
The evidence as to the relative position of purple and blue was 
previously somewhat contradictory but the purely chemical evidence 
(95) serves to show that different colours, reds, blues and purples 
can be obtained by varying amounts of the same pigment, so that 
the Mendelian evidence of the duplex nature of purple is counter¬ 
balanced by the more recent additions to our knowledge of the 
second point. 
Keeping the colour sequence in mind we can now analyse the 
colour of the corolla in the various groups:— 
Senecionece —The predominant colour in this tribe is yellow, but 
orange, white, violet and purple occur in various groups of Senecio, 
which groups have been separated by several authors on this account. 
In the Senecioninae blue occurs in Cineraria; orange and purple 
in two or three other genera; white is rare. In the Othonninae 
blue, pink and white occur rarely, while in the Tussilagininae white 
and purple become relatively commoner and in the Liabinae white is 
the only colour except the predominant yellow. The Senecioneae 
are, therefore, primitive in the colour, showing a marked predomin¬ 
ance of the basal yellow and a range of colour in outlying genera and 
outlying species of the basal genus, Senecio. The higher colours are 
usually confined to the rays, the disc in these cases being almost 
invariably yellow. 
Cichoriece —Yellow is again predominant, white rare, orange, 
pink and red commoner. There is a sudden development of purple 
and pure blue occurs in several genera. 
Calendulece —Yellow is again predominant in both ray and disc 
florets but more so in the latter. Three of the chief genera show 
orange in ray and disc sometimes and two of them, Tripteris and 
Diniorphotheca, show white and purple occasionally, the purple 
spreading to the disc in both genera. 
Arctotidece —Yellow is again predominant. In the Arctotideae 
the basal genus, Ursinia, shows yellow in both disc and ray as a 
rule with purple rays occasionally. This purple spreads to the 
disc in Arctotheca and Arctotis ; the latter shows a wide range in 
the rays with yellow, orange or purple in the disc. Orange occurs 
