—47— 



reliable characters, it seems to me they are the most 

 reliable of any we have. 



Effects of the Soil. — It is coming to be recognized 

 that apart from the constituents of the soil which make a 

 plant robust or the reverse, there are other elements that 

 have much to do with its external appearance. Mr. E. J. 

 Hill has called attention in this journal to the fact that the 

 so-called Asplcnium serpentini cultivated on rocks other 

 than serpentine soon lost its specific characters and be- 

 came A. adiantum-nigrum, while A. adulterinum in 

 time turned out to be A. viridc. Similar instances are to 

 be found in publications on ecological botany. These 

 facts suggest that some of the many species and forms of 

 Isoetes in Xew England may be accounted for upon simi- 

 lar grounds. If the character of the water in a shallow 

 pond is nearly sufficient to determine whether it shall ulti- 

 mately become a sphagnum bog or a reed swamp, the 

 character of the soil through which flow the streams 

 emptying into such a lake may have some effect upon the 

 Isoctcs growing there. Americans have thus far shown 

 far greater activity in searching for new species than in 

 reducing hastily assumed species to their proper place as 

 varieties ; but the last word in taxonomic botany will" not 

 be said until every form is given its rightful place. The 

 student who will carefully cultivate questionable species 

 under different conditions and record exact results will 

 be entitled to our praise quite as much as the species- 

 maker. The question of hybridity raised by Mr. Dodge 

 is also worth investigating. 



It is safe to say that no plant is a new species because 

 it looks like one. There are differences that are geo- 

 graphical, or seasonal, or ecological, or personal. In 

 flowering plants some of these have been considered suffi- 

 cient to characterize species ; but it is to be hoped that 

 we may ultimately find some standards by which we may 

 judge of a new form with more exactness than hereto- 

 fore, and contributions to this end are invited. 



Jolict, III 



