54 HICK : SOME RECENT ADVANCES IN BRITISH PALiEOBOTANY. 
Lepidodendron and Allied Forms. 
The work done upon Lepidodendron and the forms allied to it, 
since 1891, though good and useful of its kind, has not resulted in 
such great advances as those already referred to in connection with 
other types. In a memoir, published two years ago," Williamson 
made a further contribution to our knowledge of the structure and 
organisation of Lepidodendron Harcourtii, and gave an account of 
the structure of the leaves. He also brought forward a large body of 
fresh observations on the fossils known as Halonia and Ulodendron, 
with the object of showing that they are merely the fruit-bearing 
branches of Lepidodendra, and not independent plants as is some- 
times supposed. Finally, by the aid of specimens supplied by Mr. 
Lomax, he was able to demonstrate that the twig described in the 
Sixteenth Memoirt as Lepidodendron Spenceri, is the axis of the 
peculiar strobilus or fruit-spike, with winged spores, described and 
figured in the Ninth Memoir,J so that both structures are really 
parts of one and the same plant. 
His last independent memoir was issued in the spring of this 
year, only a short time before his death. || In it he endeavours to 
elucidate the growth and development of the arborescent Lepido- 
dendra of the Coal Measures by a study of the details of their 
organisation. In the result some of the views expressed on these 
matters in previous memoirs are more or less modified, and, to some 
extent at least, brought into harmony with those held by other 
palseobotanists. 
The fruit-spikes of Lepidodendron have been studied by Prof. 
Bower with results that have an important bearing upon certain 
morphological questions. His account of the structure of the axis of 
Lepidostrohus Brownii, Schimp.,§ brings to light quite a number of 
histological details which had previously escaped the notice of palseo- 
botanists, and which led him to institute a comparison of the stem 
of Lepidodendra with those of existing Lycopodiaceous plants. The 
results cannot be detailed here, but amongst them is the interesting 
* Phil. Trans., 1893, B. 
t Phil. Trans., 1889. X Phil. Trans., 1878. 
II Mem. and Proc. of the Man. Lit. and Phil. Soc, 4th series, vol. ix., 1894-5. 
§ Annals of Botany, vol. vii„ pp. 329-354. 
