24 ^'ol' XLIII., Art. 1.— K. Yenao : 



a) Shape and texture of sporophyll. In describing the shape 

 of sporophylls of Aleukia, the term linear, ovate, obovate, etc., and 

 their combinations have been apphed ; and for the texture, coria- 

 ceous, cartilaginous, membranaceous, etc. Generally speaking, the 

 sporophylls of Alarm are narrow and thick when the plant grows 

 on a surfing rock or near the low v/ater mark, and broad and 

 thin, when in a quiet cove or in a deeper place. McMillan^) 

 observes on A^ancouver Island that Alaria nana has much broader 

 and more sporophylls when it is found at a higher formation on 

 surfing reef. He attributes the abnormity of the form to its 

 a,daptation to the cumaphytic habitat. The fluctuation of the 

 morphological characters due to the difference of the habitats, how- 

 ever, is quite trifling in comparison to tliat due to the stages of 

 their development. 



A few of the earliest- formed sporophylls are in most species 

 different in shape and size from those formed at vigorous growth 

 of the frond. They are generally smaller and shorter, and dis- 

 tantly disposed. Many examples may be given, where specimens 

 of various species at such a stage have been erroneously identified 

 with Alaria Pylali Geev. 



After a close study of the development of sporophylls in 

 various species I can safely divide Alaria into two sections, Holo- 

 soria and ]\Ietasoria, on account of the changes of the appearance 

 and texture of the sporophylls during their growth : — 



I. HoLosoEiA. Sporophylls of the species under this section 

 are in most cases thick and coriaceous from the beginning. Their 

 growth in length and breadth stops at a certain limit and then 

 the entire surfaces, except the narrow borders, become soriferous. 

 The sori begin to appear as a continuous patch on the lower half 



1) McMillan : Cumaphytism of Aluria, p. 147. 



