19 - 
Germinating Spores in a Fossil Fern. 
reasons, in order that we may be able to distinguish between the 
sporangia of actual Ferns and the pollen-sacs of allied seed-bearing 
plants. In the meantime the object of the present note is to record 
a case in which there happens to be convincing evidence that the 
fructification in question is that of a true Fern. 
The sporangium about to be described occurs in a section (No, 
1832 in my collection) received from Mr. J. Lomax in Feb. 1903,. 
and cut from a nodule obtained from the Halifax Hard Bed. The 
sporangium, as it appears in the section, is somewhat pear-shaped 
(Fig. 60) measuring F2mm. in length, and about 1 mm. in maximum 
width. There are unfortunately no traces of the organ on which 
the sporangium was borne ; its point of attachment may not im¬ 
probably have been near the smaller end, but there is no reason to 
assume that the section is a truly longitudinal one. The sporangial 
wall, which is broken at both ends, consists of an outer, dark layer 
of cells, and an inner, more delicate zone, from one to four cells 
thick, as preserved, and in places much collapsed. In the multi- 
seriate structure of its wall the sporangium resembles those of the 
Eusporangiate Ferns. The outer layer shows a certain differen¬ 
tiation ; towards the smaller end and along the sides of the sporan¬ 
gium the cells are long and somewhat flat, their radial depth being, 
only 50-60/a, while their length in the tangential direction reaches- 
100/a ; towards the opposite end the form of the cells changes— 
they become high and narrow, the radial dimension reaching 110a 
or more, while in the tangential direction they measure only from 
30-50/a. In a section of a similar sporangium from Dulesgate,. 
probably of the same species (S. Coll. 1831), the region occupied by 
the high, narrow cells is more extensive, embracing more than half 
the circumference of the sporangium ; the two regions pass over 
gradually into each other. In this specimen the height of the 
narrow cells reaches 160/a. There is no sign that the apparent 
height of the cells is exaggerated by obliquity of section, and in any 
case there can be no doubt of the existence of a well-marked dif¬ 
ferentiation in the sporangial wall. It is most unlikely that the 
high-celled part of the wall represents a true annulus ; in all proba¬ 
bility this modification affected a considerable area of the wall; this 
is a common condition among Palaeozoic Fern-sporangia ( Scoleco - 
ptcris, Sturiella, Botryopteris, etc.), and finds its analogy among 
recent Ferns in the group of enlarged cells which discharges the 
functions of an annulus in the Osmundaceae. Professor Bower 
has already pointed out the close agreement between certain Car- 
