606 PRELIMINARY REMARKS 
ANALYSIS OF MATRIX OF SKULL OF OREODON. ANALYSIS OF MATRIX OF SCAPULA 
OF PALEZOTHERIUM. 
Water of absorption, . ; i BE See OOD é : a - 400 
Flesh-coloured, siliceous earth, insoluble in HCl. — 83-00 Silica, . : .- 59-00 
Lime, . , ; . Ca = 80-90 : . 10:00 
Carbonic acid, : . C ‘=m 19-00 ; ; P . 12-20 
Sesquioxide of iron, . 4 A ; , Fe = 2:00 ‘ ‘i B en hre0 
Alumina, ; ; . Al = 1-00 : a . 4-20 
Manganese, . ; ‘ ‘ ; ihn 1-00 
Magnesia, ; ‘ ; . Mg = 1-00 
Phosphoric acid, P : , i . = 1:80 ‘ é P . Side 
Chlorine, : : i : ; gs Sag ee ; : P . 0-037 
Potash, ; ; ; ; ; ka ee Sulphuric acid, . 0:03 
Loss and soda, ‘ : , ; : We wei; 48 Loss and alkalies, . 1-433 
100-00 100-000 
ARTICLE V. 
SYSTEMATIC CATALOGUE OF PLANTS OF WISCONSIN AND MINNESOTA, BY C. C. PARRY, M.D., 
MADE IN CONNEXION WITH THE GEOLOGICAL SURVEY OF THE NORTHWEST, DURING THE 
SEASON OF 1848. 
Tux accompanying list of plants embodies the observations I have been able to make during the past 
season, in connexion with the Geological Survey of the Northwest, under the direction of Dr. Owen. 
I have also incorporated some personal observations made during a previous season in the State of 
Iowa; being properly comprised within the District of the Northwest; and enabling me to present a 
more complete view of the botanical features of this region, than could otherwise be done during a single 
season’s operations. 
The precise region of country covered by these observations, will be sufficiently indicated by the sub- 
joined localities. The time of collection, with other points of special interest, also accompany each sepa- 
rate name, in the order in which they stand. 
The order followed is the Natural System; and the authority used, « Torrey and Gray’s North American 
Flora,” and “Gray's Botany of the Northern United States.” 
Being desired by Dr. Owen’s instructions to have special reference to the geological relations of the 
plants observed, a few preliminary suggestions on this point will not be deemed out of place. 
It is evident on the slightest observation, that all the relations of accompanying vegetation to geology 
are to be sought through the common medium of the soiZ: in go far only as any geological formation is 
capable of giving a distinctive character to this medium, may we expect to find geological characters 
equally marked on the vegetation. This fact has been particularly noticeable in the region of country 
traversed during the past season. The passage from one geological formation to another—especially 
when distinctly marked—is always accompanied with a change in the botanical features, perhaps propor- 
tioned to the extent of exposure, but still more obviously connected with evident difference in the over- 
lying soil, dependent on this geological change. 
J er example is found in the modifying influence of trap ranges upon the superincumbent vegeta- 
tion, which influence is at times so marked, that even when not exposed, the direction and width of the 
range ean be traced with considerable certainty by their means alone. 
