Jan. 1906. | THE SAVANNAHS OF GUYANA. 161 
3 feet thick, is totally or mainly coarse quartz sand; the 
second layer, a mixture of sand and decomposed vegetable 
matter, called by the natives blakka doti or black soil; and 
the third layer, a more or less loose, reddish clay, a detritus 
of old laterite rocks: more about this later on. Further on, 
pages 363 and 364, we read again: “The appearance of a 
tropical savannah remains always essentially the same, at 
least in plains. Tall grasses, in many districts exceeding 
the height of a man, spring up in dense tufts, separated by 
bare intervals of soil, which is very variable physically as 
well as chemically, and is frequently coloured red by iron 
oxide. On high plateaux the grass is shorter, frequently not 
Quartz sand. 
Garden soil. ese Sasi 
= SS LSS 
8 OG LESS, ee Ce Garden soil. 
Surface View. 
taller than in our meadows, and more intermingled with 
herbaceous perennials and undershrubs. At greater or less 
distances apart trees appear, usually as stunted, gnarled 
dwari-trees, resembling our apple-trees, but occasionally as 
lofty individuals, which as a rule belong to characteristic 
species not present in the forest. Besides dicotyledonous 
trees, palms also occur in savannahs.” According to 
this description the savannah of Guyana, situated but 
little above sea level, and even for four to six months 
of the year, sometimes*longer, flooded by the creeks and 
rivers, which have not sufficient capacity to drain the 
enormous amount of water falling from March to July at 
least, should present to us tall grasses exceeding the height 
of a man, in dense tufts, ete. Well, the grasses are there, but 
never reaching and of course never exceeding the height of a 
