542 BOTANY OF THE LIVING PLANT 



elaboration of the floral envelopes, by which are secured the attraction 

 and mechanical direction of the animal agents of pollination. 

 Secondly, in the gynoecium. Here the carpels envelop the ovules, 

 giving a much more efficient protection than the integument alone 

 can do. In more advanced epigynous types the carpels and the ovules 

 within them are sunk down into the massive tissue of the axis, thus 

 giving additional security, as well as ready nutritive supply. Lastly, 

 the evolution of a receptive stigma, and of the conducting tissue of 

 the style, combined with the wonderful mechanisms of pollination 

 seen in Angiosperms, stand in strong antithesis to the primitive and 

 haphazard methods seen in Gymnosperms. Such features, together 

 with those more specialised details of the contents of the pollen-tube 

 and embryo-sac already mentioned, leave no doubt in assigning the 

 highest place in the Vegetation of the Land to the Angiosperms. 



If any further testimony were required to the accuracy of this 

 comparative conclusion, it would be found in the fact that it is in 

 general harmony with the chronological succession of plant-remains 

 demonstrated by Geologists. 



