128 MINUTE MARVELS OF NATURE 



observe carefully we notice that these are true 

 sea-weeds, and not animal-plants. Some, instead 

 of being snowy white, are pink or purple in colour ; 

 and these are generally living plants. When they 

 are thrown up on the beach by a gale, to such a 

 height that the waves cannot again reach them to 

 carry them back into the water, the sun scorches 

 their tissue, and they become beautifully bleached, 

 thus acquiring the chalky appearance that gives 

 them a resemblance to coral. But what does this 

 mean ? True algae with hard and stony-jointed 

 fronds ? Well, the fact is simply that we have 

 here a sea-weed which has acquired the same 

 power as our zoophytes possessed, of separating 

 the carbonate of lime from the water. This it 

 deposits equally over its vegetable tissues and so 

 presents the chalky-white foliage we have observed. 

 Fig. 83 shows a more delicate lime-building weed, 

 which is found in clusters, resembling white moss, 

 among the shingle of our beaches. 



It is a remarkable feature of these lowly vege- 

 tables, that they should possess this strange power 

 of making lime incrustations from their natural 

 element the water, in the same way as the animal 

 forms which we have been considering. But it is 

 a characteristic common to innumerable forms 

 of low life which we have no space here to 

 consider. 



