Cuckoo- Pint. 255 



more respectable and dignified flowers. Now, one has 

 only got to suppose the number of buds in each head 

 largely increased, the whole head lengthened out into a 

 spike, and the spathe or sheath grown larger into a 

 completely inclosing hood, and there we have at once 

 an arum or an /Ethiopian lily. Only, as often happens 

 under such circumstances, the individual flowers have 

 now grown too small to attract the fertilising insects 

 separately on their own account ; so the spathe or hood 

 has to do duty for them all at once collectively. It 

 incloses and conceals the various minute flowers, but it 

 becomes itself coloured and attractive, so as to allure 

 the eyes of the little insects on behalf of the entire com- 

 munity. In other words, when the central flowers had 

 become so much diminished in size by disuse, by loss of 

 their petals, and by specialisation of sexes, they ran no 

 chance of getting fertilised at all unless they possessed 

 some exceptional means of attracting insects. Hence 

 those alone have survived which happened to develop 

 some such attractive organ as thehoodof the/Ethiopian 

 lily or the purple central spike of the English arum. 



And now we come at last to the final purpose of 

 all these curious structural arrangements. The object 

 of them all is of course to ensure the cross-fertilisation 

 of the different heads of flowers ; but the special way 

 in which they effect this universal end is singularly 



