THE CRUEL PLANT. 229 



proboscis could scarcely be caught at all. There may have been some 

 -other cause for the special form of anther-covering and the protection 

 of the pollinia while reaching maturity — and when the existing form 

 had been reached as to its main points, it was probably found that it 

 served for uncovering them too by insect agency, when concealment 

 was no longer desirable — and then further specialisation would ensue. 

 Perhaps many of the complex peculiarities of plants and animals, e.g., 

 the dimorphism and dioecism of parasites — may have grown into exist- 

 ing types by successive stages — a form evolved for one simple purpose 

 proving useful for a second, and advancing upon that new line. 



