2 AMERICAN MIDLAND NATURALIST 
last two decades. The earlier manuals mention several varieties 
of P. amphibium, but since the publication of P. Hartwrighti 
the idea began to spread that all the dry land plants were to be 
referred to the latter and the aquatic to the former. 
Some botanists have tried of late to persuade me—referring to 
the Symposium* at the fourteenth annual meeting of several botan- 
ical societies of America, and also calling my attention to the excel- 
lent and thorough work of Massartf on the accommodation of Poly- 
gonum amphibium to various habits—that P. amphibium had 
been changed into P. Hartwrightt and back again. The first 
idea that struck me on receiving this wonderful information was: 
“Why then is P. Hartwrightut even retained as a variety of the 
other?” Plants that change into different forms no matter how 
different, can hardly be considered even as varieties of one another. 
It would be absurd, for instance, to consider a caterpillar as a ° 
variety of butterfly once it has been shown that one evolved from 
the other. If some one had shown that P. amphibia became P. 
Hartwrightu, the logical thing to do would have been to suppress 
one of the names and relegate it altogether to synonymy, just 
as the scientists of old ceased considering caterpillars as species 
of worms when it was shown that they were Sally stages or phases 
in the development of butterflies. 
The proposition was put to me that P. Hartwrightit was 
suppressed as a distinct species because Massart had shown that P. 
Hartwrightt had been converted by actual experiment into P. 
amphibia and back again, by growing these plants in aquatic and 
terrestrial or xerophytic conditions. Here certainly there seemed to 
be ample provocation to take a sarcastic fling at taxonomists, 
especially those suspected of wanton species making, but the species 
P. Hartwrightw by a strange fate was of the making of one of the 
most conservative of all our American botanists! 
Not long ago there appeared a criticism of a botanist who pre- 
sumed to publish a new species exhibiting certain differences from a 
previously known one, such as variation in intranodal separation 
and pubescence. It was found the difference was but a change in 
* Report of the Symposium at the Fourteenth Annual Meeting, 
Chicago, Jan, 1, 1908. Cowles, H.C., An Ecological Aspect of the Conception 
of Species. Baltimore, Md., 1908, 266, 276. 
~ Massart, J. C. L’Accommodation Individuelle Chez Polygonum 
amphibium Bull, Jard. Bot. Vol. I. Fase. 2, 1902, 
