BOTANICAL SUBJECTS. 45 



imagination we can trace the seaweeds to their components, the 

 threads of cells, and finally reduce these to their unicellular 

 elements. 



In these pages I propose to take the seaweeds and ferns as the 

 progenitors of Phoenogams, and see how far the different parts of 

 the latter can be identified with parts which might be called 

 homologous in the former. 



