352 TEE SEA SHOES 



The processes are directed towards each other, and unite to form 

 a tube in which the contents of the two cells become fused together, 

 with the result that zoospores are produced. 



Among the lowest of the green sea weeds are the plants known 

 collectively as the Confervacece, which consist of delicate green 

 filaments, usually attached to rocks in dense masses, but often 

 found floating freely in the rock pools. The filaments are composed 

 of cells joined together at their ends, and are always unbranched. 



Confervse are found principally in the tide pools, especially near 

 high-water mark, and often abound in hollows in the rock even 

 above high-water mark, where the spray of the waves is mingled 

 with rain-water or the drainage from the land. They exist in both 

 fresh and salt water, and some species seem capable of thriving in 

 brackish water of any degree of salinity. 



Allied to the confervas is a group of marine algaj called Clado- 

 pliora, very similar to the former in general appearance, and found 

 in similar situations, but readily distinguished by the branching 

 of their jointed filaments. The various species of this group are 

 very beautiful weeds, their delicate filaments looking very pretty 

 as they float and sway in the water of the pools. They are also 

 exquisite objects for the* microscope ; but, unfortunately, often lose 

 their natural colour when preserved dry. They vary in colour, 

 some few being of a dull green tint, while others are bright green, 

 sometimes with a beautiful silky gloss. 



One species (C. pellucida) is more rigid than most of the others ; 

 its fronds stand out erect and firm, and are repeatedly forked near 

 the tips. It is a moderately common weed, found in the lower rock 

 pools, and may be readily recognised by the long one -celled joints, 

 from the tops of which the branches proceed. Another species 

 (C. diffusa) is also very firm in structure, so much so that its bristly 

 tufts retain their form when removed from the water, instead of 

 becoming matted together in a shapeless mass. Its branches are 

 rather long, and bear a few simple branchlets towards their ex- 

 tremities. It is found in rock pools between the tide-marks. 

 C. lanosa is a very pretty little weed, growing in dense globular 

 woolly tufts, an inch or more in diameter, on the olive tangles be- 

 tween the tide-marks. It is of a pale yellowish-green colour, which 

 becomes much paler, or is even altogether lost, when the plant is 

 preserved in a dry state, and, at the same time its fine glossy appear- 

 ance is lost. Its fronds have straight branches, all making very 

 acute angles, and they have also small root-like filaments. It much 



