A Monograph of the Genns Alaria. 21 



portance on them, — especially in immature specimens, is not ad- 

 visable. Upon this ground, the present writer mentions A. linearis 

 Steömf. and A. flagellarls . Steömf. under the " species doubtful," 

 referring to the authors who held a similar view to Strömfelt. 



Kjelmian ^) seems to have put too much stress on the breadth 

 of the midrib in describing his species from the Bering Islands. 

 Some systematist went too far in following his view tending to 

 value the breadth of the midrib above other characters, eventually 

 resulting in an awkard identification. 



When dried, the breadth of the midrib of Alaria decreases to 

 a considerable degree. In some specimens I have observed it to 

 lose 30-50%' of brea.dth on drying. The midrib of a dried speci- 

 men of A. valida Setch. et K.tellm. was 5 mm. in breadth. In 

 putting a part of the midrib in freshwater I found it to expand 

 to a breadth of 15 mm. I have not observed the species in a 

 living state and hence am not able to state the actual contraction 

 of the midrib by drying. Referring to the measurement given by 

 Setchell (22 mm.), I think the breadth regained by soaking in fresh- 

 water not to be very far from the measurement in its fresh state. 

 These examples show that the breadth of the midrib of Alaria 

 when measured in a dried specimen will often differ greatly from 

 that of the fresh specimen. 



JÖNSsoN^) illustrates an interesting example in the difference 

 of measurements of various parts of the frond of A. grandifolia 

 J. Ag. by soaking and drying. He remarks : — " These measure- 

 ments of plants in wet and dry state prove that their total length 

 is reduced l^% by the drying process, the length of the lamina 

 11. 5%, the breadth of the lamina in one case (A) 16.6%, in 



1) Kjellman : Om Beringhaf vets Algflor». 



2) JÖNS30N : Marine Algae of East Greenlan 1, i\ 22, footnote. 



