roads and several species are known to germinate from undigested 

 seeds. Among these are Polygonum Convolvulus, Chenopodium 

 album, Trifolium repens, T. pratense, and T. hyhridum. Doubt- 

 less other species are brought in by the same means. Numerous 

 fishing parties visit the region from the farming land around it, 

 carrying in the wagon bed hay or grain for the horses, and seeds 

 are scattered all along the way. Mud containing seeds may 

 adhere to tires or horses, and drop off later. Certainly various 

 other means exist also, although they have not been seen in 

 operation. 



A new cook-house was built for the biological station in 191 4, 

 and its premises showed only native species in 1914. Two or 

 three farm wagons stop daily with supplies, and through their 

 agency seven introduced species have arrived in three years. 

 These are Agrostis alba, Capsella Bursa-pastoris, Lepidiuni vir- 

 ginicum, Phleum pratense, Poa pratensis, Rumex acetosella, and 

 Taraxacum officinale. 



V. Notes on Individual Species 



During the first few years after the establishment of the 

 biological station, Lychnis alba was by no means a common plant. 

 It was not listed by Gates in 1911,* and was first noted by the 

 writer in one locality in 1912. Since then it has spread rapidly 

 and widely, and is now abundant along most country roads, 

 except in the aspen region, in old logging camps and along logging 

 roads, and in the few cultivated fields near the lake. So con- 

 tinued a migration over such diverse habitats leads to the con- 

 clusion that it is actually of recent appearance, rather than that 

 it had been limited in the past because of unfavorable climatic 

 conditions. 



Just the reverse is true of Lappula deflexa. Noted by Gates 

 in one station only in 191 1, it appeared very commonly in the 

 same region in 1914, while in 1917 it had almost completely disap- 

 peared. It was completely lacking in some fields where it had 

 been one of the commonest weeds in 1914, and did not appear in 



* F. C. Gates, The vegetation of the region in the vicinity of Douglas Lake, 

 Cheboygan county, Michigan, 1911. 14th Rep. Mich. Acad. Sci. 3: 46-106. 1912. 



