i86 PHAEOPHYCEAE 



a wavy appearance to the terminal frond. This bears the so-called 

 cryptostomata, although these are barely more than tufts of hairs 

 arising in slight depressions. The sporangia are produced on the 

 lower blades mixed up with unicellular paraphyses. The gameto- 

 phytes are protonemal in form, simple or sparingly branched, the 

 male, as usual, being composed of smaller cells with terminal, inter- 

 calary, or lateral antheridia, whilst the oogonia on the female 

 gametophyte are usually terminal. The ovum is fertilized on 

 emergence from the pore of the oogonium and the young sporo- 

 phyte develops in situ without the characteristic early appearance of 

 an holdfast. 



Alariaceae: Egregia (outstanding). Fig. 126. 



This genus is composed of two species, one having a more 

 northern distribution than the other, though both are confined to 

 the waters of the Pacific between Vancouver Island and Lower 

 California. The whole plant can be regarded as an extension of the 

 Alaria type in which each branch becomes strap-shaped and bears 

 three types of outgrowth : 



(a) Ligulate sterile outgrowths. 



(b) Small fertile outgrowths. 



(c) Conspicuous stipitate bladders. 



The female gametophyte is composed of one or two large cells 

 whilst the male plant is composed of numerous smaller ones, both 

 plants reaching maturity in from 19 days to 4 weeks depending on 

 the season of the year, e.g. the length of daylight. Maturity is most 

 rapidly reached at a temperature of 10-16° C, and although at 

 16-20° C. gamete development takes place nevertheless the 

 antherozoids are unable to leave the antheridia. 



Alariaceae: Eisenia (after G. Eisen). Fig. 127. 



The perennial sporophyte arises from a holdfast that is 

 apparently bifurcate, although the two apparent branches are 

 actually the lower margins of the primar}^ lamina. The original 

 elongate stipe, which may be as much as 15 cm. in length, is 

 persistent and bears a flattened lamina from which pinnules 

 develop. This primary lamina then disappears leaving two 

 groups of pinnules or sporophylls attached to the lower and outer 

 margin of the lamina side of the original transition area, whilst 



