41 
within the specified limits, those of the Isoetes being accompanied 
with figures of the macrospores. . 
“Ueber die Isoetes Arten der Insel Sardinien,” von Alexander 
Braun, Berlin, 1864, an interesting discussion of the Quillworts, in 
which our species are frequently referred to. 
“The Genus Isoetes in North America,” by George Engelmann, 
St. Louis, 1882 An important contribution to the subject. An 
abstract is contained in Gray’s Manual. 
“Monographic des Isoete^,” par L. Motelay et Yendryes 
Bordeaux, 1884 ; one hundred pages and ten plates. 
“The Distribution of Isoetes,” L. M. Underwood, Botanical 
Gazette , pages 89-94, 1888. 
“The Structure and Development of the Mosses and Ferns,” 
by Douglass H. Campbell : Macmillan & Co. 1895 . 
REMARKS ON THE GENUS ISOETES. 
T HE collection, examination and identification of the species 
in this genus native to New England, as elaborated 
by Dr. Engelmann in his monograph, “The Genus 
Isoetes in North America,” is doubtless a task attended with 
some difficulties. Although these north-eastern states seen par- 
ticularly rich in both species and varieties, and certainly with no 
lack of individual plants, yet it is only in very dry seasons that 
the larger portion, including nearly all the best developed plants, 
are easily accessible ; while I. lacustris and I. Tuckermani are 
nearly always deeply submerged. Plants of I. Engelmanni are of- 
ten found growing in merely damp situations, but they are much 
smaller and less developed than those which are immersed. It re- 
quires also, considerable experience before the eye readily distin- 
guishes these plants from the immature sedges and rushes which 
ordinarily are their companions. 
