498 Expedition to the 



and the petal-like nectaries, which compose the flower, are 

 found accurately* closed upon each other, forming a cone of 

 about an inch in length. In this situation they remain if the 

 weather be clear, until about sunset, when they gradually 

 expand. If the weather is dark and cloudy, with a humid 

 atmosphere, they are awakened from their slumbers at an 

 earlier hour. We have, in some instances, seen them fully 

 expanded early in the afternoon, but this has always been in 

 stormy or cloudy weather. In this particular, the Bartonia 

 bears some resemblance to the great night flowering cereus, 

 to which it is closely allied, but the gaudy petals of the ce- 

 reus once unfolded, fall into a state of irretrievable collapse, 

 whereas the Bartonia closes and expands its flowers for many 

 days in succession.* 



A number of young magpies were seen in the bushes about 

 the river, also the nests and young of the mocking bird, 

 (Turdus orpheus, Vieil.) 



The prairie-dog villages we had observed to become more 

 frequent and more extensive, as we approached the moun- 

 tains, and we had now constant opportunities of contrasting 

 the stupendous elevations of the Andes, with the humble 

 mounds cast up by this interesting little animal. We observ- 

 ed in the numerous burrows, an appearance of greater anti- 

 quity, than in those more remote from the mountains. Many 

 of the mounds occupy an extent of several yards in diame- 

 ter, though of but inconsiderable elevation, and with the ex- 

 ception of the present entrance, overgrown with a scanty 



* Other plants were collected about this encampment, among which we 

 distinguished an interesting species of Ranunculus, having a flower some- 

 what larger than that of R. fluviatilis with which it grows, often extend- 

 in;:, however, to some distance about the margins of the pools in which 

 it is principally found. R. amphibius; sk oder, flouting or decumbent, leaves 

 rei»>forrn, four or five lobed, divisions cuneate-oblong, margin crenate, pe- 

 tioles long- and alternate. The submersed leaves are, in every respect, si- 

 milar to the floating ones. Pentstemou erianthera, N., Poa quinquefida, 

 Poientilla anserina, Scrophularia lanceolata, Myosotis glomerata.TS.? &c, 

 were also seen here. 



