No. 11.] THE BRYOPHYTES OF CONNECTICUT, 17 
function of holding the plant more firmly in place, and are 
confined to certain species and genera. 
The archegonia are borne at the apices of stems or of 
special branches and stop their further elongation. The leaves 
and underleaves which develop in the immediate vicinity of 
the archegonia are more or less modified, and are designated 
bracts and bracteoles respectively. -Taken together they con- 
stitute the. involucre. This often surrounds the developing 
sporophyte and helps protect it. In the majority of the genera, 
however, the gametophyte develops a special protecting organ. 
This usually consists of a hollow tube, open at the top and 
enclosed by the involucre; and, since this tube is theoretically 
formed by the coalescence of modified leaves, it is called a 
perianth, although it is not homologous with the perianth in 
flowering plants. In a few cases the fertile branch takes on a 
peculiar growth as the result of fertilization, and forms a 
hollow cup around the sporophyte. This is known as a 
perigynium, and may be either pendent or erect. In the latter 
case the uppermost bracts and bracteoles are often carried up 
on the outside. In very rare instances the young sporophyte 
penetrates the tip of the fertile branch, which serves directly 
as a protecting organ without undergoing marked modifica- 
tions. Under these circumstances the calyptra itself often 
fails to develop. 
The Jungermanniales are about nine times as numerous in 
Connecticut as the Marchantiales. Less than one seventh of 
the recorded species are Metzgeriaeez, the others being all 
Jungermanniaceez. A few are more or less aquatic, either 
floating on the surface of the water or attached to submerged 
rocks or stones. A few others are to be found in bogs or 
swamps. The remainder grow on rocks, on banks, on earth, 
or on the trunks of trees, usually in damp and shaded localities. 
They vary greatly in size, a few being hardly perceptible to 
the naked eye, while others attain a length of ten centimeters 
or more. The sporophytes, with few exceptions, reach 
maturity in the spring. 
