206 IP o t e i t a 



the stipe below the base of the lamina, 

 and these develop into leaf-like pinnae 

 reaching a length, in vigorous plants, of 

 three or four feet. Successive pinnae 

 are developed in acropetal order until 

 the plant comes to consist of a mass- 

 ive trunk two or three inches in 

 diameter, bearing at the end a large 

 tuft of ribbon-like leaves with eroded 

 apices, only one of which, the central 

 lamina, was originally established as 

 such. In Alaria tufts of small laminae 

 or sporophylls are produced upon the 

 stipe below the main leaf. In Egregia, 

 innumerable small outgrowths arise both 

 upon the stipe and upon the lamina, 

 some of those upon the stipe becom- 

 ing inflated into bladders which serve 

 to buoy up the organ, others giving 

 rise to soral patches, while those upon 

 the lamina contribute to the starch- 

 making tract of the plant. When ma- 



