76 



geological processes and maintains a relict flora, "the antiquity 

 of which greatly antedates any of the rest of the vegetation here- 

 abouts, so far as permanency of position and phytogeographic 

 isolation are concerned." Perhaps the most convincing botan- 

 ical evidence introduced in support of this contention is the 

 fact that of the 565 plants which comprise the total number of 

 indigenous species known from the pine-barrens, 386 are true 

 pine-barren plants; in other words, so far as New Jersey is con- 

 cerned, they attain their optimum development within this area. 

 Two species seem to be endemic to the pine-barrens, two are 

 "practically unknown" outside of this area, and it might have 

 been added that, according to Stone,* fifty-five have not been 

 found elsewhere in New Jersey. The author also finds evidence 

 favoring his isolation theory in the extra-territorial distribution 

 of certain pine-barren plants. The occurrence in the mountains 

 of eastern Tennessee of several typical pine-barren species is 

 thought to have an important bearing on the question, while the 

 northward distribution of Schizaea pusilla and Aster nemoralis 

 is also regarded as significant. f 



" If this theory is correct, then the pine-barrens can no more be 

 considered as a new or pioneer vegetation, but rather an old or 

 climax condition, ancestrally infinitely more ancient than any- 

 thing in the surrounding area." At first thought, this statement 

 seems quite at variance with current ecological conceptions, but 

 such is not really the case. The New Jersey pine-barrens lie 

 within a region whose climate is capable of supporting a highly 

 mesophytic forest, and this type of forest represents the climax 

 or ultimate type of vegetation throughout the area. In com- 

 parison with it the vegetation of the pine-barrens, from an 

 ecological standpoint, must be classed as a primitive or pioneer 

 type. But while the successional trend of vegetation throughout 

 the east is unmistakably toward a mesophytic condition, and 

 -while the climate undoubtedly favors the development of a meso- 

 phytic forest, it must be recognized further that the actual attain- 

 ment of such a climax postulates the existence of favorable 

 edaphic conditions. Local conditions, however, such as soil 



* New Jersey State Mus. Report 19 lo: 75. 



t In this connection see Fernald, Rhodora 17: 67-69. I9i5' 



