Clcaz 



vei's. 



127 



be quite indistinguishable. Thus the fruit is not in 

 this plant a mere ripe form of the ovary, but is a 

 compound organ consisting of the calyx outside, and 

 the ovary inside, with the tube of the corolla quite 

 crushed out of existence between them. 



Last of all, let us look at the prickly fruit itself in 

 its ripe condition. Some small fly has now fertilised 

 the head with pollen from a brother blossom ; the 

 corolla and the stamens have fallen off; the embryo 

 seeds within have begun to swell ; the mother plant 

 has stocked them with a little store of horny albumen 

 to feed the tiny plantlets when they are first cast 

 forth to shift for themselves in an unsympathetic 

 world ; and now the fruit here is 

 almost ready to be detached from the 

 stalk and borne to the spot where 

 it must make its small experimen 

 in getting on in life on its own fig. 29. 



account. Before I tell you how it ^^^^'t of cleavers, 

 manages to get itself transported free of cost to a 

 suitable situation, I should like you to observe its 

 shape and arrangement. It consists of two cells or 

 carpels united in the middle, and each of these contains 

 a single seed. Once upon a time there were several 

 cells, as there still are in some of the tropical Rubiacese, 

 and each cell contained several seeds, as is the case 



