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Zone 2, the portion, two or three inches wide, just above the waterline, which 
■was kept saturated with water by capillary attraction. 
Zone 3 includes all of the mats above zone 2. 
I have studied fifty or more plants from each of zones 1 and 2, and many 
from zone 3, eliciting the following facts: 
In zone 1 genetic buds are few, and I found no male buds, hence the moss 
is probably dioicous, but the inflorescence is not proven; and the plants of the 
var. spinifolium have few or no paraphyllia, while the plants of modified fili- 
cinum have many paraphyllia as in normal filicinum. 
Zone 3 is Amblystegium filicinum, (L.) De Not. in nearly pure culture, and, 
so far as I can find, contains no Amblystegium irriguum (Wils.) B. & S. 
Zone 2 consists of Amb. filicinum in process of modification towards var. 
spinifolium , or, as named in Dixon and Jameson’s Handbook, “var. vallis- 
■clausae .” This is shown by the gradual darkening of the color, as the moss ap- 
proaches the waterline, where it has become indistinguishable from the moss in 
zone 1, and by the leaves becoming narrower and slightly longer, thus becoming 
less deltoid, and more lanceolate in outline, and by the costa changing to per- 
current or long excurrent. In zone 2 I also find many plants of var. spinifolium , 
a few of them being modified towards Amb. irriguum , but no normal irriguum. 
Zone 1 consists almost entirely of the variety spinifolium Schimp., mixed 
with occasional plants of the modified filicinum of zone 2 ; and I found one plant 
with a few leaves of apparently normal irriguum , while all the remaining leaves 
were var. spinifolium. 
It is well known that both Amb. filicinum and Amb. irriguum produce a 
variety “ spinifolium ,” and that these varieties resemble each other so closely 
that they can be separated only by the experts, and not always by them. 
What is the moss in zone 1? It is var. spinifolium , but is it a derivative of 
filicinum or of irriguum? 
I thought I had a clear case in favor of filicinum , as I found no 
normal irriguum in the region around the spring, while filicinum was common, 
and all the mats growing in connection with the var. were filicinum. The variety 
is also probably dioicous. The authorities all say that this var. of filicinum has 
few or no paraphyllia. The filicinum in zone 2 was undergoing modification 
towards the variety. 
Two of our experts write me as follows: 
Rev. H. Dupret, of Montreal, writes: “Both your Nos. 3413 and 3414 are 
a very interesting form of irriguum , the var. spinifolium , Schimp.” 
Dr. Grout writes more fully: “The moss above the spring is certainly Amb. 
filicinum. The moss in the water is to my mind certainly what Sullivant called 
Amb. irriguum spinifolium. The fact that they grow so closely associated proves 
nothing in itself. To my best judgment there is no doubt that your moss is 
Hyp. irriguum var. spinifolium of Amer. authors Irriguum and 
filicinum are more closely related and their -forms intergrade more, here in Amer- 
ica, than has been realized by students of European mosses. I have repeatedly 
-expressed my disbelief in the value of the arrangement of male and female buds 
