BIOLOGICAL PAPERS I23 



It can hardly be doubted that rhis formation is a pioneer rather 

 than a rehc, and therefore an expression of the dimate of the 

 region. In the course of nature it would doubtless have become 

 the dominant type in much of the region. 



J?. P bills strohus. 



The most unusual feature of the plant geography of Ogle 

 County is the occurrence within its limits of a grove of unmixed 

 White Pine. This species contributes a very picturesque feature 

 to the scenery of Pine Creek but is not numerically important, 

 with this single exception. On the eastern side of the canon-like 

 valley of the creek immediately south of the C, B. tSc O. Railway 

 the blults are occupied by a fine growth of pine which is so dense 

 as to exclude every other tree and shrub. The grove covers about 

 twenty acres. Adjoining it, on the same side of the creek, is a 

 rectangular timber lot of about i6o acres, much of which is not 

 pastured. This growth consists almost wholly of white oak, 

 though there are a few scattered cherries and pines. The under- 

 growth is unusually heavy, including, besides the young oaks, 

 Conius, etc., which is common in such places, also a really sur- 

 prising growth of young pines of all sizes. In many places they 

 are literally coming up like grass. 



It is evident that if the pines are here a disappearing type, it 

 cannot be because the factors of soil and climate are unfavorable 

 to them, and one feels in looking at the sturdy growth of young 

 pines that they stand about as good a chance as the young oaks 

 of conquering the region. It is the testimony of old residents 

 that this grove did not exist in early days but that it has been 

 produced naturally since the settlement of the country. It is 

 said to be less than seventy years old, and this is corroborated 

 by the age of the trees and other biological evidence. 



So far as the writer is informed, this is the only stand of the 

 species in the State. Associated as it is with scenery of great 

 natural beauty, it is to be hoped that some way will be found 

 to preserve this unique feature from destruction. 



-/. Bottom Associations. 



The bottom associations are such as are familiar everywhere. 

 I shall merely remark that they show no points of special interest 

 excepting that the scarcity of sycamore, hackberry and cork elm 

 indicates that this may be near the northern limit of these species 

 in the valley of Rock River. 



