CHAPTER XV 



SEA WEEDS 



WE now pass from the animal to the vegetable kingdom, our 

 object being to give a general outline of the nature and distribution 

 of the principal marine algae or sea weeds that grow on our shores ; 

 and to supply a brief account of those flowering plants that either 

 exhibit a partiality for the neighbourhood of the sea, or that 

 grow exclusively on the rocks and cliffs of the coast. The present 

 chapter will be devoted to the sea weeds themselves, but we 

 consider it advisable to precede our account of these beautiful and 

 interesting plants by a brief outline of the general classification of 

 plant-life, in order that the reader may be able to understand 

 the true position of both these and the flowering plants in the 

 scale of vegetable life. 



Plants are divided into two great groups, the Cryptogams or 

 Flowerless Plants and the Phanerogams or Flowering Plants. In 

 the former the reproductive organs are not true seeds containing 

 an embryo of the future plant, but mere cells or spores, which give 

 rise directly to a thread or mass of threads, to a cellular membrane, 

 or to a cellular body of more or less complexity of form from which 

 the flowerless plant is afterwards developed ; while in the latter the 

 reproductive organs are flowers that give rise to true seeds, each 

 of which contains the embryo plant. 



The Cryptogams are subdivided into four groups the Thallo- 

 phytes, the Charales, the Muscvnece, and the Vascular Cryptogams. 



The first of these includes all the very low forms of vegetable 

 life, the simplest of which (Protophyta) are minute plants, each 

 consisting of a single microscopic cell that multiplies by a process 

 of budding, no sexual organs of any kind being produced. Some of 

 these minute unicellular organisms contain chlorophyll the green 

 colouring matter of plants, by the action of which, under the 



