Mil. W. SOWEKBY ON THE MANGllOYE THEE. 



20 



tropical countries ; it delights in salt swamps and the low shores 

 of the ocean. Dr. W. Hamilton thus describes its mode of 

 growth : he says, " In the economy of nature the Mangrove per- 

 forms a most important part, wresting annually fresh portions of 

 the land from the dominion of the ocean, and adding them to the 

 domain of man ; this is effected in a twofold manner — first by the 

 progressive advance of the roots, and secondly by the aerial ger- 

 mination of the seeds, which do not quit their lofty cradle till 

 they have assumed the form of actual trees, and drop into the 

 water with their roots ready prepared to take possession of the 

 mud in advance of the parent stems and repel to a further and 

 perpetually increasing distance the invasion of the water. The 

 progression by means of the roots is effected by fresh roots which 

 issue from the trunk at some distance above the surface of the 

 water, and, arching downwards, penetrate the mud and become in 

 time independent trees ; thus a complicated labyrinth of vegeta- 

 tion is at length formed, serving to arrest the particles of soil 

 washed down from the interior of the country and raise the level 

 of the ground ; the shallow water is thus converted into a salt- 

 marsh, and the salt-marsh progressively dry land. These roots 

 afford attachment to myriads of small but delicious oysters, which 

 are left bare during the efflux of the tide, giving rise to the 

 popular fable of oysters growing on trees" 



After several unsuccessful attempts, we received, in June 1867, 

 many young plants of the Mangrove in very good condition ; the 

 very healthy state in which they arrived at the Grardens is due to 

 the care given to them by the officers of the Royal Mail Steam 

 Navigation Company, who brought home the case I had specially 

 prepared and sent out to the West Indies. Of the young plants, 

 which are from 1 to 2 feet high, some have been grown in pots 

 entirely submerged in sea water, others are only occasionally 

 watered ; but all are kept in a moist warm stove, and are at the 

 present time, August 1868, in good health ; they root very freely, 

 and the roots appear not to be injured by the decomposing soil, 

 which occasionally becomes putrid. The plants have not yet 

 thrown out any aerial roots ; the growth of the stems is inter- 

 mittent, giving them the appearance of having been grafted. 



