(26) 



There are not wanting characters sufficiently marked to separate it 

 without much difficulty from F. nodosus ; but whether these characters 

 may prove permanent and not the result of accidental circumstances, is a 

 different question, and one not so easily determined. The more cylin- 

 drical stems, the very different origin of the branches, the entire absence 

 of the marginal teeth, the different fructification, are all characters 

 which can be readily recognised and appreciated. Yet the general 

 resemblance of the two species is such, combined with the singularly 

 anomalous habitat of the species, as would naturally induce us to exercise 

 caution in deciding the question without more careful observation of the 

 species in their native habitats. 



It is said to inhabit quiet, muddy, or stony bays, resting unfi,ttached 

 on the muddy shore or among boulders, forming dense bundles of a 

 more or less roundish form, and in this state to be tossed about at the 

 mercy of the waves, and yet to produce fruit in abundance. 



It would be very desirable to ascertain with certainty whether the 

 plant may not be found in the vicinity in an attached state, and the 

 anomalous forms, not merely such as have been detached by the violence 

 of the waves. 



' €) 



3 '^^I^SSSgjpJ 





FUCUS MACKAII. 



EXPLANATION OF DISSECTIONS. 



Fig. 3. — Receptacle cut across. 



2. — Section of conceptacle with spores. 

 3. — Section of conceptacle with antheridia. 

 4. — Spores. All magnified. 



