212 THREE CRUISES OF THE '' BLAKE." 



" Talisman " constantly crossed long bands of Sargassum trail- 

 . ing according to the direction of the winds and the currents, 

 and forming larger or smaller patches, which were, however, 

 rarely more than four or five yards square. Yet the " Talis- 

 man " crossed the Sargasso Sea from north to south in the areas 

 indicated in the charts as the most prolific in Sargassum. 



The weed as described by the younger Milne-Edwards does 

 not differ from that which we have frequently examined. The 

 central stalk and the basal leaves are usually of a brownish tint, 

 the terminal leaves, on the contrary, of a greenish-yellow golden 

 tint. The same animals as those commonly found in the gulf- 

 weed of the West Indies were collected by the " Talisman." The 

 number of fishes alone, perhaps, is somewhat more varied. The 

 botanist attached to the expedition did not succeed in finding 

 any branches with reproductive organs, although the terminal 

 shoots were in most active states of development ; and he came 

 to the conclusion, as Harvey and others had done before him, 

 that, while pelagic, the Sargassum increases merely like a cut- 

 ting of extraordinary vitality. We were not fortunate enough 

 to find it in fructification, but Professor Moseley states that he 

 saw specimens covered with fructification in Harrington Sound, 

 Bermudas. 



Only by placing a piece of the gulf -weed in a jar of sea- 

 water, with abundant space for it to expand, do we get an idea 

 of its beauty and its graceful form. The delicate fronds, of all 

 shades, from deep oHve to golden yellow, are often crossed by a 

 delicate tracery of hydroids and of bryozoan reticulation, which 

 stands out in bold relief of white upon a dark background. 



In the " Narrative of the Challenger " is given a list of the 

 species of animals occurring on the Sargassum. Many ob- 

 servers have described the antics performed by the hosts of 

 Crustacea when shaken out of their hiding-places, and have 

 dwelt at length on the phenomena of mimicry noticed among 

 the Crustacea, moUusks, annelids, and other animals which make 

 their abode among the fronds, stems, or air-vessels of the gulf- 

 weed. At first glance the bunch of weed seems deserted, but 

 shake it in a glass dish, and hundreds of many-colored deni- 

 zens are seen rushing about in all directions, eager to return to 



