5- 
University Museum sent purties to northern Michigan to make 
biological studies in the Porcupine Mountains and in Isle 
Royale. One party, led by ])r. Ruthven, spent one month in 
the Porcupines and the remainder of the season on Isle Royale. 
The report of this expedition fl) came out in 1905* It covers 
both regions, listing 91 species of plants, and notes the 
ecological distribution of the more important species. 
A list of over 600 plants found in the neighboring 
county of Gogebic should be mentioned. It was based on work 
done by Dr. £• ii. Bessey and the writer (10) during portions 
of the summers of 1919 and 1920. 
LOCATION AND PHYSIOGRAPHY. 
The Porcupine Mountains are in Ontonagon County in 
the Northern Peninsula of Michigan, in lat. 47 0., long. 90 w. 
(see map). Thoir unique position, close to the south shore of 
Lake Superior, has already been pointod out. Thoy reach a maxi- 
mum altitude of 616 m. above sea level or 435 tn. above the level 
of the lake. The top of the first range or ridge comes within 2 
km. of tho shore. Its north slope is rather gentle, but becomes 
increasingly stoop as one approaches the summit, finally 
reaching a height of 275 m. abovo the lake in sec. 14, T. 51 B. 
R. 43 W. There is then a sudden descent of about 120 m. to 
the valley Of Carp River, half of this descent bOfcng, in 
places, vertical rock face, at tho base of the cliff there 
