INTRODUCTION 31 



like Gomontia (Fig. 50), which bore into and inhabit 

 shells. The whole of the investing substance may be 

 thus removed, and the Alga disclosed without any 

 breaking up of its filaments or injury to its cells. In 

 other respects the ordinary methods of microscopical 

 examination are sufficient. 



In considering the economic uses of seaweeds, the 

 indirect service they render as the basis of the nutri- 

 tion of animal life in the sea, and consequently their 

 fundamental importance for fishery, must not be left 

 out of account here, as it practically has been by 

 fishery boards and others whose main concern it 

 might appear to be. In investigating the food of 

 fishes, the so-called practical inquirer is accustomed 

 to look no further than the immediate organisms 

 eaten, much as if in agricultural matters no heed 

 were given to the pasturage of farm stock. There is 

 no doubt that the enormous shoals of Peridiniece and 

 other allied free-floating Alga3 are the pastures on 

 which the organisms constituting the food of fishes 

 themselves feed that in fishery matters they are the 

 basis of the pyramid of which man is the apex, and 

 the dearth of knowledge of these forms and the indif- 

 ference of fishery authorities to the subject in its 

 technical aspect, is only equalled by the ignorance 

 and apathy of botanists towards its scientific value. 



The direct economic importance of Algae is no 

 longer so great as it was early in the present cen- 

 tury, when the kelp industry flourished in the north 

 of Scotland and the western coasts of Scotland and 

 Ireland. The value of kelp in the manufacture of 

 soap and glass became greatly enhanced by the 



