xvi 



INTRODUCTION. 



rock and lift up the coarser plants which often fringe the edge of such places, and look 

 underneath for delicate CoralUiias (Plates XXXIII., XXXIV.), Polysiphordas (Plate 

 XXVI., &c.), and other scarcer things, or she will come away knowing nothing of 

 the pools at all. But, alas! here is no space for fully pursuing this subject. Only 

 remember that the perpendicular faces of rocks have their growths as well as the 

 pools, and that a good collector must, like a good nurse, keep her eyes open all 

 round her; while, on the other hand, the injunction cannot be enforced too strongly, 

 that she had better go home hurriedly than overload her basket and spoil everything 

 it contains. 



It will be understood, of course, that what has now been said of Filey Bridge 

 applies to other rocky shores, although the zones of growth are more easily observed 

 there than elsewhere. But they exist everywhere — everywhere grass-green is the 

 earliest life in the first vegetation-line; mixed gradually with some of the more 

 delicate olive plants, Ectocarpus (Plates XIX. &c.), Asperococcus (Fig. 46), &c. 

 Everywhere the LamimriaSj and the rarer red plants, are to be found only at low- 

 water level, but the popping sea- weeds, the Fuel (Plates III. and IV.), throughout 

 the whole range, save only the extreme last. Exceptions excepted, an examination 

 of any shore will prove these statements correct, and enable the collector to judge 

 whereabout she is, algologically speaking, on even a perfectly strange coast, and to 

 regulate what she looks for, accordingly. 



Another subject of interest to the algologist is the influence of climate on the 

 growth of special plants, for this may often decide her in a choice of stations. Sea- 

 water varies very much both in temperature and saltness, and it would be as 

 unreasonable to look for Devonshire myrtles in Yorkshire gardens as for Devonshire 

 algse in its waters. But here latitude is not everything. Douglas Bay, in the Isle 

 of Man, is in nearly the same latitude as Filey, yet both the land and sea vegetation 

 are very different; and if it be asked why, no reason can be assigned but Giolf- 

 stream influence. The point is open to discussion and objection, perhaps; and there 

 is a theory (with a diagram in its favour!) of a current which diverts the Grulf- 

 stream from going further east than the Scilly Isles, and prevents its going up the 

 Irish Channel at all, while it allows its influence* on the west coast of Ireland. But 

 if this be so, how is it that the blue snail shells {lantliina fragilis) and Portuguese 

 men-of-war (Fhi/saUa pelagica and Velella spirans), which it is universally admitted 

 are drifted to Ireland and Scilly from hot latitudes by the Gulf-stream, are also 

 found along the coasts of Cornwall and Devonshire? Surely this diverting current 

 off the Scillys is rather a mythical idea? Moreover, it is not Captain Maury's 

 belief, who figures his lines of influence as extending not only up the Irish Channel, 

 but a few of them along the south coast of England and slightly north-east beyond, 

 until lost in the stronger downward current from the North Seas. 



People may adopt which theory they like best, but those who have seen the coast 

 of County Clare, the Isle of Man, and the north-east shores of England, will have 

 a strong leaning towards Maury's creed. It solves all the difficulties presented to 

 them by the different appearance of the waters in those places, and the different 

 vegetation to be found in them. Sea-weed collectors need only be told that SplicB- 

 rococcus coronopifolius (Fig. 191) exists at Douglas, and Odonthalia dentata (Fig. 99) 

 at Filey, to be aware that there must be some very decided cause to account for 



