THE MARINE BOTANIST. 81 



to the narrow, veinless leaflets which arise from the 

 stem, while in Laminaria it is generally dispersed 

 over the fronds in cloud-like patches; the spores 

 are very minute, taken in connection with the 

 large size of these plants, and they can only be 

 detected in old plants, full gTown, consequently 

 specimens in fruit cannot be entered in the Her- 

 barium from their unwieldy size ; small portions 

 of such it is, however, well to preserve when in 

 fi'uit, for the sake of comparison. Young plants 

 of the large growing kinds, as Laminaria digitata, 

 may be found at an early stage, exhibiting the 

 peculiarities of their growth, and well suited for 

 collections. The perennial species are found to 

 change their fronds yearly; the young frond 

 arises at the base of the old frond, gradually en- 

 larges, and by degrees pushes it off : this change 

 is not confined to old plants, but takes place in 

 those of all ages. Small specimens of L. sac- 

 charina, and L. Phyllitis, when perfect, and well 

 preserved, so as to exhibit the delicate foldings 

 of their fronds, their soft, pale gi*een colour, and 



