178 IN THE GUIANA FOREST. 



the open space, the floating-island grass (Panicum 

 elephantipes] anchors itself to the mocca-mocca or 

 bushes, and extends just as far across as the rapid 

 current will allow. In dry weather, when the 

 water is low, and the stream has little power, the 

 extensions from either side meet in the centre, and 

 close the passage-way for a time, only, however, to 

 be torn away in great masses as the floods come. 

 At such times great patches, fifty feet or more in 

 diameter, are seen floating down -stream, some- 

 times carrying with them monster camoudies (Boa 

 murina), or other snakes. As these masses are 

 caught by the sea-waves, they are thrown back 

 upon the beach, where they lie in great heaps 

 until, dying, they go to help make up that exten- 

 sion of the coast-line which is continually driving 

 back the waves to a greater distance. Sometimes 

 a great tree, whose timber is light enough to float, 

 gets entangled in the grass, and becomes the 

 nucleus of an immense raft, which is continually 

 increasing in size as it gathers up everything that 

 comes floating down the river. The grass extends 

 over the whole, and mats it together until a 

 formidable obstacle is produced, but notwithstand- 

 ing all its efforts the dam is imperfect. When 

 eight or ten inches of rain fall in a day, and the 

 river rises sixteen to twenty feet, the barrier must 



