JF 
OF THE MATTO GROSSO EXPEDITION, 1891-92. 277 
. through tall grass, as high as a man. This grass is Andropogon condensatus, H. B. K., 
var. paniculatus. Growing in the grass you will see here and there the Allamanda-like 
Thevetia bicornuta, Muell. Arg., a Paraguayan species found as far to the north as 
Corumbá, and on the river-bank you will find Angelonia Gardneri, Hook., Teramnus 
volubilis, Sw., the curious Baillonia amabilis, Bocq., Tephrosia brevipes, Benth., Mimosa 
cinerea, Vell, and grasses (Panicum, Setaria, Imperata brasiliensis, Trin., and the new 
genus Pogochloa), while the inevitable camalote swarms at the waterside. 
There is little more to tell. Soon after leaving Coimbra we reached the region of the 
Caranda forests; dead logs of these trees were taken.on board, for they yield excellent 
fuel. On Feb. 3rd we were at Puerto Pacheco, a small settlement founded by the 
Bolivians, but then in possession of a Paraguayan force. A short ramble in the neigh- 
bourhood yielded several plants of interest, including Prosopis ruscifolia, Griseb., a Chaco 
type with very large and strong spines; the Argentine Tabebuia nodosa, Griseb., a curious 
plant having Cuban affinities; Coccoloba paraguariensis, Lindau; Paspalum simplex, 
Morong; and new species of Wissadula, Mimosa, Morrenia, Croton, and Julocroton. 
But we could make no stay here; our funds were exhausted, and it was necessary to 
hasten on to Asuncion; at that place, which we reached on Feb. 7th, the expedition 
was disbanded. 
SHORT SKETCH OF THE CLIMATOLOGY OF MATTO Grosso. 
In order that we may understand the origin and nature of, and satisfactorily study 
the relations borne by the flora of a country to that of neighbouring regions, some 
knowledge of its climate, if it be not essential, is, at least, manifestly advantageous. I 
trust therefore that no apology is needed for presenting to the reader the following short 
sketch, to a large extent compiled from various available sources. Nor have I refrained 
from adding a few observations made by myself during our expedition. It must be 
understood that at Santa Cruz, the climatology of which is quite unknown, with the 
exception of a couple of ordinary thermometers, we had no recording instruments 
whatever; that we went there in the expectation of making but a short stay; and that, 
for all we knew, the order for our departure might arrive any day. Hence it did not 
seem worth while to commence a series of observations which must necessarily have 
proved most imperfect, and were liable to cease at a short notice. 
- The dry season lasts from March or April to September, and during this period storms 
and rain are exceedingly rare. They do sometimes occur, however; thus, on the night 
of Aug. 11th, when we were nearing Cuyabá, on our upward journey, a violent thunder- 
storm, accompanied by a perfect deluge of rain, broke over the country. At the beginning 
of September a premonitory storm or two pass over, soon followed by the regular wet 
season. For a tropical country the rainfall is not high. Dr. Morsback *, as the result 
of three years’ observations, got an annual average of 1166 mm., that is between 45 and 
46 inches, only a trifle greater than the rainfall at Rio. The reason for this must, I 
think, be sought in the geographical position of the city, and in the nature and direction 
of the prevailing winds, which blow mostly from the north, north-west, and north-east. 
* * Revista do Observatorio,’ Rio, 1890, p. 91. 
