288 
and of having become isolated in bogs and other edaphically 
favorable locations, such as probably were only to be found 
on Beacon Hill at that time: Triglochin palustris, Panicularia 
obtusa, Scirpus subterminalis, Carex livida, C. exilis, Utricularia 
intermedia and Aster nemoralis. There are a good many more,” 
and the same phenomenon has been noted by entomologists. 
Prof. Smith writes of Trechus chalybeus, and a few other insects, 
that “the only trace of real boreal species has been found in the 
deep cold swamps of Ocean County.” 
In this connection the distribution of the most remarkable 
plant of the pine-barrens, Schizaea pusilla is very interesting. 
It is found only in the pine-barrens and in Nova Scotia and New- 
foundland, and is unknown between these points. If Dr. 
Scharff's recently proposed theory?! that perhaps parts of Nova 
Scotia and Newfoundland remained unglaciated through all 
the period of the Pleistocene is correct, then it is not impossible 
that Schizaea is a relict in the pine-barrens of its southern 
migration, and that it is also a relict in the north, all the inter- 
vening territory having been preémpted first by the ice, second- 
ашу by more “agressive” plants after the recession of the ice. 
This is little more than interesting speculation, but Scharff, 
whether wrong or right in his contention, has opened up a wide 
field of discussion. It is certainly significant that Schizaea is not 
found in the unquestionably glaciated country, and is found only 
in the pine-barrens and in the [probably] unglaciated northeast. 
Another feature of the pine-barrens which may support the 
theory that they are a very ancient and isolated phytogeo- 
graphical entity is the number of parasitic, saprophytic and 
mycosymbiotic plants that grow there. Cowles, in his recent 
à treatment of those plants not wholly dependent on their own 
roots for food, has made the suggestion that the origin of the 
"parasitic, saprophytic, and mycosymbiotic habit may have 
2 Stone, W, loc. cit. 49, 50, and 76. 
? Ann. Rept. N. Jersey State Mus. 1909: 30. 
” Scharff, К. F. Distribution and origin of life in North America. New York 
* Coulter, J. M., Barnes, C. R., and Cowles, Н. C.  Text-book of Botany. 
2: Ecology, 775 and 799. 1911. 
