224 RAMBLES OF A NATURALIST. 



My first zoological excursions were very unsuc- 

 cessful. The sea, like the earth, has its times of 

 repose, and when I arrived at Saint Sebastian at the 

 beginning of winter I was at first fearful that I 

 should not meet with any good subjects of study. 

 The laminated rocks of Point Antigua, and the sands 

 and muds of the Urumea, exhibited numerous traces 

 of the presence of marine animals, but their tubes 

 and galleries were for the most part empty; their 

 inhabitants having migrated to greater depths.* 

 I was already trembling at the thought of my pro- 

 bable want of success, when, in one of the small and 

 narrow gulfs which are enclosed by the harbour 

 between the mountain and the hills, I found pieces 



action of time, could preserve this mould, and hence fossils of this 

 kind present a very great interest. I do not believe that any of 

 those -which have hitherto heen discovered afford us any insight 

 into the anatomical organisation of the Annelids of these ancient 

 seas. In this respect, the specimen which I brought from Saint 

 Sebastian may perhaps be regarded as unique of its kind. Unfor- 

 tunately, however, the rock in which it was deposited is very friable, 

 and the voyage has to a certain degree injured some of the minuter 

 details which could previously be traced with the greatest exact- 

 ness. 



* These migrations of the lower animals are as yet very imper- 

 fectly known. I have on different occasions observed that they 

 were as rapid and as general as those of animals which occupy a 

 higher place in the scale of being. Thus, for instance, at the end 

 of October, at different points of the coast of Normandy, one is often 

 unable to find a single sea urchin where perhaps a week before they 

 might have been gathered by thousands. I have made a precisely 

 similar observation in respect to one of the most remarkable 

 Annelids of our coasts. We see, therefore, that these Radiata and 

 Articulata possess the same instinct as many birds which, on the 

 approach of winter, abandon mountainous heights and seek refuge 

 in the plains and valleys. 



