younger parts of the stem in old plants, are flat and leaf-like, bi-pinnate ; 

 the pinnules furnished with a midrib, and muciferous pores, with a crenate 

 or subdentate margin, and varying from a line to two or three lines in breadth. 

 Receptacles one or two lines long, simple or forked, smooth, subtorulose, 

 lanceolate, terminating most of the upper pinnae of fertile specimens, and 

 frequently subtended by vesicles. Colour dark in the stem ; a pale olive in 

 the branches. Substance between coriaceous and cartilaginous, brittle when 

 dry. 



I follow Turner, and all succeeding British writers, in uniting, 

 under the common name foeniculacea, the Fucus discors and F. 

 abrotanifolius of Linnaeus, which continental authorities, without 

 exception, retain in the rank of species. So far as a judgment 

 may be correctly formed from dried specimens, I fully agree with 

 Mr. Turner, that " each shape passes into the other by gradations 

 so imperceptible that no line can be drawn between them "; and 

 this excellent author further remarks, that in separating it into 

 distinct varieties, he has rather yielded to the feeling of weakness 

 than followed the dictates of his judgment ; fearing that if he 

 did otherwise, he might be accused of presumption, or even of 

 a worse motive, in refusing to find characters sufficient even for 

 varieties, where other botanists have had no hesitation in laying 

 down such as constitute species. I have not myself had much 

 opportunity of examining the living plant, but I place implicit 

 reliance on the accuracy of the observations made during many 

 years familiarity with this species, by my often mentioned friend 

 Mrs. Griffiths, who states that such specimens as grow in deep 

 water, where they are seldom or never exposed by the tides, 

 constitute the F. discors of authors, especially if collected in 

 summer, at which season they are extremely luxuriant, with 

 broad leaves and large air-bladders ; and that fronds which are 

 developed in shallow tide-pools, or collected late in autumn or 

 winter, being more branched, and having narrower leaves, make 

 the F. abrotanifolius. On the depth of water, or difference of 

 season, therefore, depend all the characters on which it has been 

 attempted to erect two species. 



Cystoseira fceniculacea : — of the natural size. 2. Portion of a leafy branchlet. 

 3. Air-vessels and receptacles. 4. Transverse section of a receptacle : — 

 more or less magnified. 



