32 BOTANICAL GAZETTE [JANUARY 
life from 14 to 38 years. Some had been dead for a long time, while 
others showed evidence, in needles still clinging, of having been 
alive until very recently. All had undergone severe suppression. 
In consequence of the deep shade the undergrowth was extremely 
sparse, except in the lower left-hand corner where there was a 
partial opening. Here was a luxuriant growth of mosses, including 
Hylocomium proliferum (dominant), Hypnum  crista-castrensis, 
Calliergon Schreberit, and Dicranum undulatum. The close group 
of young balsams occupying this locality was largely due to layering. 
Quadrat 4 then includes in the main a group of balsams of very 
different sizes, giving an appearance of gradual reproduction, but 
in reality essentially even-aged, and belonging distinctly to a single 
generation. 
Quadrats on the main Isle Royale 
It has been said that the conditions on Smithwick Island include 
one that is somewhat abnormal for the region as a whole, namely, 
that the exposure to wind is greater. Two quadrats in sheltered 
localities on the mainland of Isle Royale were studied for the 
purpose of comparison. They probably represent the opposite 
_ extreme so far as exposure is concerned. 
QuaADRAT 5 (figs. 11, 12) was located a few hundred meters 
back from the southeast shore of the Blake Point peninsula in sec. 
23, T. 67 N., R. 33 W. The locality is thoroughly sheltered from 
northwest vind by the main ridge, and from the lake winds by 
the islands to the southeast. On the diagram several points of 
difference from the preceding quadrats are readily seen. Most 
noticeable are the greater average age of all species and the absence 
of very young growth. Two new trees appear: Picea mariana 
(Mill) BSP (black spruce) and Larix laricina (DuRoi) Koch 
(tamarack), each species being represented by one individual. The 
whole stand is remarkably even-aged, 22 of the 38 trees being 
between the ages of 82 and 98 years. There is some tendency 
toward grouping of trees of similar age, though not so noticeably 
as on Smithwick Island. The group a is a very marked one, 
however. Of the 9g individuals of 4 species composing it, 7 are 
between 83 and 92 years, and 5 between 89 and 92. The effect of 
