FUCUS VESICULOSUS. 



77 



made, and the little protuberances or black spots on the surface 

 showing at a fig. 2 are the conceptacles. There are six of them 

 in the section showing different stages of perfection. The con- 

 ceptacle in the upper right-hand corner of the illustration was 

 more highly magnified and is seen in fig. 3. 



A, fig. 3, are the interlacing filaments which fill up the whole 

 central part of the enlarged ends of the Branches. The outer 

 surface, b, consists of small, thick-walled cells closely packed 

 together, and loaded with mucilage. The cell-walls often con- 



/ \ 



fig. 4. Oogonium, F. Vesiciilosus. a. Cells of the Inner Surface. 



b. Young Oogonium. c. Protoplasm, e and f. Membranes. 



d. Hairs. X2OO diameters. 



sist of two clearly distinct layers ; the inner, firm, compact ; 

 the outer, gelatinous and capable of swelling greatly in water. 

 These cells can be plainly seen with a magnifying power of 

 200 diameters, or when the surface of the plant is examined, 

 but not distinctly on a cross-section. The cell contents is granu- 

 lar and has not been well investigated. The contents appear 



