— 31 — 
Paris Index shows half a page of synonymy for this species, beginning in 
1791, and a critical study of Kindberg’s and Limpricht’s descriptions of this 
and other species of the genus Ditrichum will show you that confusion still 
exists, which can only be solved by more and better field study! 
The same is true of many other common and variable mosses, such as 
Fissidens adiantoides, Fuiiaria hygrometrica, Physcomitriiim turbinatum, 
etc. so that any one desiring a chance to experiment need only gather any 
one of these species, bring them into the house, put them in a covered glass 
dish, watch them, and keep notes. It is desirable, however, to find out first 
what you have before any' changes take place, because a curious thing 
happened a few years ago in the laboratory of the New York Botanical 
Gardens. Dr. Richards and Dr. MacDougal were conducting some physiolo- 
gical experiments in testing the influence of illuminating and other gases 
upon plants. ^ 
Some species of mosses were found to be particularly resistant to the 
influenceof Carbon monoxide, and lived and grew in an atmosphere that was 
sufficient to kill any other plants ! But the singular thing that happened was 
that in a species of Bryuni the stems grew very tall and slender, the leaves 
were depauperate and produeed in their axils, an abundance of propagating 
bodies exactly like those of Pohlia pj'oligera\ yet as far as we know this 
species does not occur wild within the limits of the garden, and this peculiar 
condition may have been due as much to the excess of moisture and close 
eonfinement as to the illuminating gas. What the species was before it took 
on this unusual habit of propagation no one knows, and the leaves were too 
poorly developed to tell. The plant simply could not achieve its usual repro- 
duction so it accomplished an abnormal progagation. 
Now this sort of thing, and others just as interesting, occur continually 
in nature, with the result that we get new specific and varietal names ad 
nauseam, without any explanations of the conditions. Mr. Williams, who has 
had a large and varied experience as a student and collector, tells me that in 
Montana near Great Falls, where he collected mosses for seven years, it fre- 
quently happened that a moss would fruit well and abundantly one year, and 
then not occur again in good condition for two or three years. We know 
this is true of the paper-white narcissus. Some years it flowers profusely, 
last spring for example was a wonderful year for bulbs of all kinds, but other 
years, either due to late frosts, or a dry season, the flowers will be blasted. 
1. Richards and McDougal, The Influences of Carbon monoxide and other Gases upon 
Plants. Bull. Torr. Bot. Club 31; 57, 66 and 167. 1904, 
