Ixxix 



December 4, 1882. 



The President in the chair. Ten members present. 



Dr. Engelmann presented specimens of jumping-seeds from 

 La Paz, Baja California. Mr. G. W. Barnes, of San Diego, who 

 forwarded the seeds, says of them, 



they are called by the natives "Viuda Favela." The seeds jump out of 

 sight when wet. The leaf of the plant is used by the natives as mucilage. 

 They also use the seeds in extracting sand and dust from the eyes. 



The jumping of the seeds was due to the breaking of the pod due 

 to internal strains when wet, and results in the sudden scattering 

 of both seeds and the resulting fragments of the pod. 



Dr. Edward Evers presented the Academy with thirty maps 

 of Lower California, made from surveys by the U. S. ship Nar- 

 ragansett. 



Mr. Wm.McAdams, ofjerseyville, Ills., exhibited a collection 

 of fossils from the drift of the valleys of the Illinois and Missis- 

 sippi rivers, and made remarks as follows : 



The deposits of the drifts, as seen in digging wells and making other 

 excavations, as well as in the precipitous exposures made by water-cours- 

 es, consist usually of a reddish-brown clay, underlaid by a bluish plastic 

 clay lying on the surface of the rock, which is usually reached in both Illi- 

 nois and Missouri at a depth of less than one hundred feet. This depth 

 is, however, sometimes exceeded where the valleys of ancient streams are 

 met with. 



Mingled with these drift clays are many boulders and masses of rocks 

 of great interest from the fact that they are often of different material from 

 any rocks we have in place in Illinois. It is quite common to find granite, 

 porphyry, greenstone, and other primary rocks,, that have evidently come 

 from the region of Lake Superior. It is not uncommon to find masses of 

 native copper, doubtless from the same northern locality. The present 

 specimens of this copper are from the drift in the neighborhood of Alton 

 and near Grafton. It is quite probable that a period of many years elapsed 

 — ages, in fact— during the subsidence of the glaciers ; and, although it 

 may not be quite certainly ascertained that man beheld the phenomena of 

 this epoch, it is quite certain that many strange animals braved the rigors 

 of the climate and evidently flourished. Some of these animals were of 

 strange appearance, and, where their bones are discovered protruding 

 from the clays, one is astonished at their size. From the clay in the side 

 of a ravine in Calhoun county, Ills., we recovered the jaw of an elephant 

 beside which Jumbo would seem small. One of the teeth from this fossil 

 iaw, and which we present for inspection, weighs nearly eighteen pounds, 



