1912] DEUTSCH—TARGIONIA 407 
which they are borne slopes forward’and downward at the time the 
archegonia are mature. The development of this ‘fruiting surface’’ 
runs as follows. The archegonia, arising as they do in acropetal 
succession, check to a great extent the vegetative growth behind 
the growing point. The apical cell, however, is not immediately 
concerned, and continues its segmentation with practically no inter- 
ruption. The natural result of this is that the apical cell is carried 
forward and out. Thus the archegonial surface is finally brought to 
lie in a sort of pit or depression in the anterior end of the thallus. 
On the lower and outer margin of this pit is the apical cell, which, 
when this stage is reached, ceases to function. 
The involucre—The development of the involucre is so closely 
allied to that of the archegonial surface, that it is extremely difficult 
to say just where the one leaves off and the other begins. It is 
simply the continued forward growth of the tissues immediately 
surrounding the shallow pit at the anterior end of the thallus, with 
the natural result that the opening to this pit is narrowed, and begins 
to close up. It is never completely closed, however, although in 
the earlier stages the edges of the wings are brought very close 
together. As the involucre matures, the outer surface, as well as 
the inner margin of the wings, becomes highly cutinized. 
That the involucre is not, as reported by CAVERs (3), a result 
of the stimulus given by the act of fertilization is shown in one of 
the preparations, where it was complete and well developed, while 
the eggs of the archegonia it surrounded were still unfertilized. 
Calyptra.—The calyptra is a simple and very delicate structure, 
soon ruptured by the growth of the sporophyte. At maturity it 
is 2-4 layers thick at the base. 
Sporophyte body 
Capsule.—The capsule is a comparatively simple affair. The 
wall consists of a single layer of cells, uniformly thickened with 
spiral and annular bands. There is no special mechanism for 
dehiscence. In his recent report on Targionia, CAVERS (3) figures 
and describes a rudimentary elaterophore, represented by a few 
spirally thickened cells depending from the distal portion of the 
capsule. This statement could not be verified in any of the sections 
