38 ^'ol XLIII., Art. 1.— K. Yendo : 



epidermal coll, bnt those of the stretched ones nearly as largo as 

 two or three epidermal cells taken together. A nnmber of the 

 glands have also been found on the surface of the stipe. 



As the embryonal blade elongates further by stipo-frondal 

 growth, the monostromatic part is eroded away by degrees. This 

 generally takes place when a frond has attained 6-7 cm. in total 

 length. At this stage, the mucilage glands are much denser than 

 in the preceding stage, and much larger in size and greatly elon- 

 gated. Very frequently, two, three or more of the elongated glands 

 are found continuous together, forming a simple or ramified pas- 

 sage. See Plate XVIII, figs. 9-11. The small circular ones may 

 be seen near the transition region only and along the very margins 

 of the blade. The content of the gland is granular and colourless. 

 The glands in the stipe undergo no marked change in their shape 

 and size. 



When the frond has grown to measure more than 12 cm. in 

 total length, the contents of the older mucilage glands turn 

 into a dark brownish colour even in the living material. In 

 general, the glands in the region up to 20-30 mm. from the transi- 

 tion region are colourless and gi'anular ; but those in the upper 

 parts of the blade, except the newly formed young ones, are all 

 brownish (Plate XVIII, figs. 8-10). 



The longitudinal stretching of the glands while yet young, 

 appears to follow the longitudinal elongation and the multii)lication 

 of the epidermal cells. This can be concluded from the fact that 

 the disposition of the epidermal cells is not at all disturbed upon 

 or around the glands. But in the later stages, generally after the 

 content has turned into a dark brownish mass, the glands gain 

 in width and the epidermal cells around the opening become radi- 

 ately disposed (Plate XVIII, fig. 9, a). In Undaria pinnatifida, the 



