64 



purposes. The various advantages of this process are obvious. 

 As a means of interesting both young and old in becoming 

 acquainted with the trees of their neighborhood this method 

 has no equal and need not be dwelt upon in the present connec- 

 tion. As an aid to paleobotanical work it is also extremely 

 useful. It is not necessary to dry the leaves as fresh ones 

 answer equally well, although dried leaves from the herbarium 

 give equally good prints if they are reasonably flat and not too 

 brittle. The prints show both surfaces as the result of a single 

 operation and the varying appearance of the vascular system 

 on the two surfaces is especially valuable for comparison with 

 fossil leaf impressions. From fifty to one hundred can be made 

 within an hour and with a little practise the results are uniformly 

 excellent. The accompanying illustrations are chosen to show 

 this feature although these particular prints are much less artistic 

 than dozens of other leaf species which might have been selected. 

 The upper figures show the upper and under print of a leaf of 

 Quercus Chapmani while the lower figures show the corresponding 

 surfaces of a leaf of Quercus myrtifolia, both oaks of our extreme 

 southern states. 



Johns Hopkins University, 

 Baltimore, Maryland. 



A NEW PLUM FROM THE LAKE REGION OF 

 FLORIDA 



By Roland M. Harper 



The lake region of Florida,* which was scarcely known to 

 botanists before the researches of Mr. George V. Nash in 1894,! 

 has yielded a rich harvest of plants new to science, probably 

 at least 75 species, about half of which are not at present known 

 outside of this region. By far the greater number of these were 

 discovered in the central part of Lake County by Mr. Nash in 

 the year named, and many of them were described by him. 



*The boundaries and most striking characteristics of this region have been 

 indicated by the writer in Ann. Rep. Fla. Geol. Surv. 3: 223-224. pi. 16. 1911. 

 tSee Bull. Torrey Club 22: 141-161. 1895. 



