26 THE AMERICAN NATURALIST [Vol. XLIII 



Fig. 36. Egregia growing in a thick bed of kelp in which are prominent 

 Alaria (with a midrib) and Hedophyllum (in foreground, especially at right). 



far as the writer knows, nothing like it occurs in other 

 kelps save in Thallasiophyllum. It is a matter of great 

 interest from several points of view. Morphologically it 

 gives the best reason for considering Egregia the highest 

 of the Alariataf, although that position would probably be 

 accorded it without question because of the differentiation 

 of the ordinary proliferations alone. The other members 

 of this subfamily produce outgrowths which function as 

 sporophylls, and in some of them, e. g., Eisenia, these be- 

 come the main photosynthetic areas of the plant. The 

 development of meristems in such outgrowths, leading to 

 the formation of branches, is the next step towards greater 

 complexity and the logical summit of the Alaria series. 

 But its greatest interest is from the ecological point of 

 view. The extreme length of the stipe pushes the grow- 

 ing point far out, where it is lashed severely by the waves 

 and frequently destroyed. Were the plant dependent on 

 this for its continued healthy existence, as in Laminaria, it 

 might easily be killed or at least handicapped for a con- 

 siderable part of the time by the loss of the blade until a 

 new one could be regenerated, as in many species of 

 Laminaria. But, should the older branches be injured, 

 these basal branches may develop at any time. By their 



