TRANSACTIONS OF SECTION K. 1045 



making the embankments give rise to garden, corn-field, and meadow plants 

 characteristic of the ground broken in making the cuttings. 



After traffic has been established on the line, a new source of weeds is opened. 

 By the continual packing, unpacking, and carriage of merchandise, station sidings 

 become the homes of certain weeds which are found in such places and transported 

 by the same means over most of the temperate world. Their seeds spread along 

 the line from these centres, drawn by the natural draught along the slopes in some 

 cases, carried on the trains in others. 



From the beginning there has also been a third agency at work, the natural 

 encroachment of the surrounding vegetation. 



On the average railway bank we nnd a large proportion of native species, a few 

 visitors either established or constantly reinforced by traffic, and lastly an occa- 

 feional straggler resulting from the original composition of the bank. 



FRIDAY, SEPTEMBER 9. 

 The following Papers were read : — 



1. A Method of obtaining Material for Illustrating Smut in Barley. 

 By W. G. P. Ellis, M.A., Bot. Laboratory, Cambridge. 



By sowing soaked, skinned barley that had been plentifully covered with Vstilago 

 spores a supply of smutted barley may be ensured, and in such material it is easy 

 to trace out the spore formation. 



Hand section of the ear when about f inch long showed the mycelium at the 

 growing points of the flower shoots, and in such sections the mycelium, at first 

 intercellular, could readily be found becoming intracellular and of much greater 

 diameter. Branches became very numerous, and in the hyphte and branches spores 

 ■were formed. Towards the central parts spore clusters were too dense for exami- 

 nation, but nearer the epidermis the branching and arrangement of the sporogenous 

 hyphse could more easily be made out ; and the teasing of the lateral flowers of 

 each notch of the rachis was often more successful than if the central — and only 

 flower of the ordinary ear — were taken. Sections were mounted in water, and 

 some in 1 per cent. KOH, and it is but fair to say that such treatment has failed 

 to show any septation of the hypha as a preliminary to spore formation. Material 

 for microtome sections was prepared as follows : — The leaves of a barley shoot 

 were stripped down so as to expose the apparently highest node, and the part an inch 

 or two above this was cut oft'; tlien by a series of successively lower horizontal 

 cuts the youngest leaves were removed until in the space they enclosed the tips of 

 the awns or ear were seen ; then a cut was made through the node and the re- 

 moved ear was placed in Flemming's or Rath's solution for fixing, the ear thus 

 being a very few seconds only between plant and reagent. 



If a smutted ear be removed and kept floating on water, its spores continue to 

 develop, and in several cases they matured first in the awn. It was by no means 

 uncommon, on teasing out young fruits from such an ear, to find that the spore had 

 germinated. 



I have not yet made similar observations for Tilletia, as my bimted wheat was 

 less forward than my smutted barley, but I am satisfied that by this method of 

 working, class material for illustrating Bunt and Smut may easily be obtained. 



2. On a neio Medullosa, from the Lower Coal-Measures of Lancashire. 

 By D. H. Scott, M.A., Ph.D., F.R.S., Hon. Keeper of the Jodrell 

 Laboratory, Royal Gardens, Keio. 



Our knowledge of the remarkable fossil stems referred to the genus Medullosa 

 of Cotta has hitherto been based entirely on Continental specimens, chiefly derived 



