100 THE CYSTOSEIEA. 



glides smoothly along, a bush here and there of large 

 size springing from the bottom, conspicuous above 

 the olive and purple bed of common weeds by its 

 light greenish grey colour. These are the plants in 

 question. It is difficult to procure a growing speci- 

 men, for the rocks to which the plants are attached 

 are here all rather large and heavy masses, and the 

 depth of water even at low-tide prevents the use of 

 the hammer and chisel. By means of a boat-hook, 

 however, I have torn up considerable portions of a 

 shrub, from which I have then carefully severed un- 

 injured branches, which, being bound to the surface 

 of a shell or stone, survived some time in an Aquarium, 

 and displayed their remarkable gorgeousness of colour 

 to great advantage. None of this is visible when the 

 specimen is removed from the water ; it is a shrub 

 with stout compact branches of a pale yellowish-olive 

 hue, set with needle-like leaves, whence its trivial 

 name of ericoides or " heath-like ;" while another 

 marked character is the swelling of the branches into 

 oval air-bladders, which, though solitary in this species, 

 more generally run in strings of several in succession, 

 as indicated by the generic name Cystoseira or " Mad- 

 der chain." But the moment the plant is submerged 

 all its glory returns : the pale olive branches become 

 invested with a most brilliant flush of iridescent light 

 blue, not changeable in tint, though varying in inten- 

 sity according to the play of light that falls upon it. 

 Thus it may he compared to some Christians, who 

 are dull and profitless in prosperity, but whose graces 

 shine out gloriously when they are plunged into the 

 deep floods of affliction. 



