208 



fern comparatively abundant in this swamp, about equally abun- 

 dant with either of the spinulose ferns. The Clinton fern was 

 somewhat less abundant, and the crested fern proved its presence 

 by two plants found. The swan^p is about half a mile long and 

 about ten rods wide, narrowing at the ends. It is a rather wet, 

 half-shaded swamp with little undergrowth of shrubs, but with a 

 few large trees and a herbaceous undergrowth of which the ferns 

 form a prominent part. 



Again, under the guidance of Mr. \Vm. H. Smith, I found 

 Boott's fern September 8 at Maplewood, X. J. It is true I 

 found only three plants of it, but at the same time I found only 

 one of the crested fern and only a few spinulose ferns. The main 

 part of the swamp vi.sited has been cleared of timber and is over- 

 grown largely with weeds, chiefly Polygointm arifoliuin L. , so the 

 conditions are no longer favorable for swamp wood-ferns. 



From my observations I am led to believe that where the 

 conditions are favorable for the crested fern or for the Clinton 

 fern, Boott's fern is likely to occur. These ferns seem to require 

 similar conditions. Boott's fern and the crested fern appear to 

 me to be closest in their requirement of light, since they are found 

 in open sunny places where the Clinton fern does not usually 

 grow. These ferns are more rare in their general distribution in 

 this region than either of the spinulose ferns and may be classed 

 among the rarer ferns. On the other hand any one of the three 

 is less rare than Goldie's fern in the localities I have examined. 

 I have found the crested fern in more localities than Boott's fern, 

 and the latter in more places than the Clinton fern. In regard 

 to the question of hybridity I can neither prove nor disprove the 

 theory. The fact that D. cristata and D. spinulosa occur with 

 D. Bootlii may mean simply that these ferns require similar con- 

 ditions. On the other hand attention might be called to the 

 fact that their position in swamps or on the border of swamps or 

 of ponds is favorable for the mingling of the spores or of the 

 gametes during the seasons of the }-ear when there is considerable 

 water present. That Boott's fern "is exactly intermediate 

 between its possible parents " can not be taken too literally, and 

 this is a point against the theory of the hybrid origin of the fern. 



