On the Megaspore of Lepidostrobus foliaceus. 117 
From such measurements as it has been possible to make, there 
were probably several, perhaps four, megaspores in each sporangium. 
Turning to the appendage it seems clear, that in Plate VIII., 
1719 and 1217, where the veins are radiating out from the point of 
attachment, are sections through the appendage in one direction, 
Fig. 24. Photograph of 1217 (Plate VIII.) 
while 1539, 1343 and 1715 are cut at a plane at right angles 
to the former, and the veins are cut vertically. In 1715 there 
appears to be a cleft filled by hairs, which may be where the 
microspores gained access to the megaspore. In 1887, a much 
less well-preserved specimen, there are microspores in the cleft. 
At a, a, these microspores are shown enlarged. 
I have made a model of the appendage and spore, which appears 
to explain the appearance of the different sections. It reminds one 
of the so-called “ swimming-apparatus” of Azolla. 
The appendage was evidently a fairly substantial structure, 
which resisted distortion much better than the megaspore itself. 
The nature of the structure cannot be determined, but it is not 
cellular and its appearance indicates, that it was part of the cell-wall 
probably derived from the tapetal protoplasm. 
There is some evidence of this origin in the case of the bristles 
of other megaspores. 
While examining Lepidostrobus foliaceus, further details of which 
will be found in Mr. Maslen’s 1 paper on Lepidostrobus, I came across 
megaspores of this plant in their sporangium in connection with the 
characteristic bract (Plate VIII., 5 and 1403 and Text-fig. 25). 
This point is of especial interest as up till now the cone has always 
been considered homosporous 2 . 
We must turn to Professor Williamson’s splendid specimen of 
1 On the Structure of Lepidostrobus. Trans, of the Linnean 
Society. Vol. V. 1899, P. 373, Plate 38, Figs. 36—39. 
2 On the Organization of^the Fossil Plants of the Coal-Measures, 
Part XIX. Phil. Trans. Royal Society, Series B. 1893, P.27, 
Plate 9, Fig. 57. 
