THE MARINE BOTANIST. 17 



than in the Bladder Fucus, and more transparent. 

 Perennial. Spring- and Summer. Grows on rocks 

 and stones between tide-marks 5 land-locked bays 

 and estuaries, and where fresh water flows into the 

 sea, are its favourite growing places, but it is not 

 entirely restricted to such localities. Not very 

 common, though found in many places, from 

 Orknev to Cornwall. 



FUCUS SEERATUS. - SERRATED OR 

 TOOTHED FUCUS. 



Frond with a distinct midrib, divided, the 

 margin regularly toothed ; without air-vessels. 

 Receptacles flat, swelling up in the tips of the 

 fronds, and either containing (on different plants) 

 roundish spores or antheridia; when the latter, a 

 thickened, orange-coloured liquid exudes through 

 the pores in drying ; a drop of which, if placed 

 under the microscope and wetted with salt water, 

 will disclose countless numbers of zoospores, or 



c 



