143 
carp. The four prominences (including the original apex of the 
fertile segment), are beyond doubt to be regarded as leaflets, 
which, however, are never much elevated above the surface of the 
young fruit, and in this first stage form four slightly elevated 
ridges. 
A little later (Fig. 3), these become more prominent, and a 
slight depression or pit is formed between the base of each and 
the cells occupying the top of the young sporocarp. These pits 
are separated laterally by the coherent margins of the leaflets 
which extend to the axis of the sporocarp and are continuous 
with it. The young fruit now enlarges rapidly, and as it does so 
the depressions deepen owing to the elongation of the leaflets, 
and also to that of the cells of the axis of the sporocarp, which 
form a sort of columella running through the center. 
The leaflets, or as we will now call them, lobes, are only free 
at their tips; and as the edges are in contact from the first and 
extend to the axis, the clefts between them and the axis form four 
‘deep cavities that open by as many pores at points opposite the 
tips of the lobes. These pits correspond to the ‘ canals” de- 
scribed by Russow in the fruit of Marsilia. 
Juranyi states that these cavities are caused by a splitting 
apart of the cells of the inner tissue of the sporocarp, and that 
the communication with the outside is brought about by the sub- 
sequent separation of the cells at the apex of the sporocarp; that 
is, that the cavities are endogenous in origin. Doubt has been 
expressed as to the accuracy of these statements, and Goebel 
States that his observations do not bear them out. 
A study of longitudinal sections of the young sporocarp 
show beyond doubt the strictly external origin of these cavities. 
Up to the time that the cavities begin to form, the young 
fruit is composed of a uniform, small-celled parenchyma, but a little — 
later, however, the primary tissue systems are differentiated, and 
the separation of the body of the sporocarp from its peduncle 
becomes evident. About the same time the axial cells in 
the basal part of the sporocarp extending into the peduncle, 
elongate and form the beginning of the single fibro-vascular bundle 
that traverses the peduncle and joins that of the sterile ae of 
the leaf near its base. 
