194 



practically under xerophytic conditions. This would tend to 

 render the root system inefficient as a means of water absorption 

 and make the possession of a water-storing organ like the pitch- 

 ered leaf of great advantage to the plant. 



The epiphyte Nepenthes represents the highest degree of adap- 

 tation, in that it produces a protein-dissolving enzyme, the nepen- 

 thin of Vines (Ann. Bot. 15: 563. 1901). Even here, how- 

 ever, the absorption of protein by the leaves is not absolutely 

 essential to the life of the plant, though of great advantage. 

 Nepenthes, then, stands at the upper limit in the evolution of 

 plants with pitchered leaves, while San^aceiiia purpurea is near 

 the lower limit. Between them are numerous forms with vary- 

 ing degrees of adaptation. 



New York Botanical Garden. 



SPECIES AND VARIETIES 



By T. D. a. Cockerell 



The recent discussions on the. species question, particularly 

 that of the Botanical Society, printed in the May number of the 

 American Naturalist, show at least one thing — that the matter 

 may be regarded from very diverse points of view. This being 

 so evident I beg permission to add yet another to the already 

 numerous collection. 



Politically, I am an American ; but biologically, an English- 

 man, with many of the idiosyncrasies of that singular race. 

 According to current report, one of the peculiarities of the Eng- 

 lish is a limited sense of humor. I rather incline to the opinion 

 that this is not wholly to their discredit ; but nevertheless, I am 

 far from proposing legislation to prohibit anyone from making a 

 joke unintelligible to the Anglo-Saxon mind. Such restrictions 

 have probably never been contemplated in respect to jokes, but 

 are they not a little like those desired by botanists, who insist 

 that all species must be discernible to general students of plants? 

 Such persons talk about the creation of species by botanists, show- 

 ing thereby, and in other ways, their opinion that species are purely 

 artificial things. Their attitude toward species is something like 



