12 Vol. XLi;i, Art. 1.— K. Yendo: 



The length of the blade varies greatly according to the species. 

 Of A. fistulosa, K.JELLMAN^) reports to have measured its largest 

 specimen in the Bering Sea at about 60 feet. Miyabe^) states that 

 it is said to be as long as 200-250 feet. I have measured a 

 specimen about 85 feat long which was cast ashore on Shimuf 

 shn Island, the northern extremity of the Kuriles. The breadth o- 

 tlie blade of this species attains nearly 3 feet. This species no 

 doubt has the largest simple blade in the vegetable kingdom. In a 

 specimen of A. tœnlata I found the blade to be 3.5-5.0 cm. in 

 breadth and 3.70 meters in length — recalling a stripe of bandage. 

 In other species, however, the length of the blade, absolute or in 

 proportion to the breadth, is much less than those two examples. 

 Generally, the maximum breadth of a blade is at a point about 

 1/5-1/3 of the whole length from the base. 



In most species of Alaria, if not in all, the blade splits pin- 

 nately, like a 3Iusa leaf, in the older parts. In certain species 

 there seems more or less differentiation of the tissue adapted for 

 this process. The cortical layers as well as the hyphal cells of 

 the medullary layer of the blade run at large patently from the 

 midrib, and the epidermal layer is composed of angulate cells dis- 

 posed in less fixed direction. In A. fistulosa, A, macropteria, etc., 

 the fine parallel wrinkles which give a marked feature to the older 

 portions of the blade, are principally due to tlie peculiar arrange- 

 ment of the medullary tissue (Plate II, fig. 2). The mechanical 

 force of the waves acting upon the blade splits it in the resultant 

 direction of the hyphal cehs. 



The segments of the split blade are rectangular, if the split- 

 ting is in the direction at right angles to the midrib, and more or 



1) Kjellman: Om Beringliafvets Algüor.a, p, 41. 



2) Miyabe: Laminaria Industry of Hokkaido, p. 52. 



