REPORT ON FORESTS. 179 



the Deciduous and the Coniferous ; and the contrast between 

 the two is so obvious as to attract the attention of every observer.* 

 Doubtless to many the fact that the former is roughly confined 

 to the hilly northern part of the state and the latter to the 

 plain region further south, might seem sufficient to account for 

 the limitation of the two classes of vegetation simply on climatic 

 and physiographic conditions. If, however, the line of demarka- 

 tion between them be followed across the state, or better yet, if 

 it be followed beyond the confines of the state, it may be seen 

 that it does not coincide with any parallel or latitude or any 

 isothermal line, but crosses these in a northeast and southwest 

 direction, and is more or less independent of surface irregu- 

 larities. 



If, now, a geologic map of the state be examined, the line of 

 demarkation may be seen to parallel very closely the general 

 trend of the outcrops of the geologic formations, and the inference 

 becomes irresistible that these must be taken into account in 

 any investigations which concern the problem of forest distribu- 

 tion in the state. Investigations were therefore made from that 

 point of view, and as they proceeded the fact became more and 

 more apparent that not only were the two classes of vegetation 

 strongly identified with certain geologic formations, but also 

 that the distribution of several species in each of the classes were 

 similarly limited. 



This line of investigation is capable of extension so as to 

 include a far larger number of species than were actually 

 brought under observation, and there is no doubt that if the 

 entire flora of the state could be mapped, from the same stand- 

 point, an exceedingly interesting contribution would result. If, 

 further than this, the investigation could be made to cover the 

 entire geographical area comprised within the areas of distribu- 

 tion, the interest and possible value of the work would be cor- 

 respondingly increased. Such an investigation would, however, 

 imply many years of careful study in the field, and all that can 

 be attempted in this report is to outline the known facts of dis- 

 tribution in regard to certain species of trees in the state and to 

 draw from those facts such conclusions in regard to the probable 

 causes as may seem to be warranted. 



* For a brief discussion of the subject see Dr. N. L. Britten's " Catalogue of Plants Found in New 

 Jersey," introductory chapter, Final Report State Geologist, Vol. II, 1889. 



