134 THE STOEY OP THE PLANTS. 



flowers clustered, as in cuckoo-pint, on a thick 

 club-stem, and they have an open spathe, which 

 more or less protects them. Our English sweet- 

 sedge is still at this stage of evolution. The 

 marsh-calla of Northern Europe and Canada, on 

 the other hand, has a handsome white spathe to 

 attract insects, while its separate flowers, still 

 both male and female together, have each six 

 stamens and a single ovary. But they have lost 

 their perianth. The common white arum or 

 "calla lily" of cottage gardens has a bright 

 yellow spike in its midst, and if you look at it 

 closely you will see that this spike consists 

 entirely of a great cluster of stamens, thickly 

 massed togetherT~Tne top of the s~pike~is entirely 

 composed of such golden stamens, but lower 

 down you will find ovaries embedded here and 

 there among them, each ovary as a rule sur- 

 rounded by five or six stamens. Lastly, in the 

 cuckoo-pint the lower flowers have lost their com- 

 plement of stamens altogether, while the upper 

 ones have similarly lost their ovaries ; moreover, 

 a few of the topmost have been converted into 

 the curious lobster-pot hairs which assist, as I 

 have shown you, in the work of fertilisation. 

 We have here a singular and instructive example 

 of what may be described as retrograde develop- 

 ment. 



And now we must go on to those modes of 

 fertilisation which are effected by agencies other 

 than insects. 



