176 An Exhibit of Palaeozoic Seeds. 
plants and left in the soil. Heavy crops of wheat were taken the 
first year, but in subsequent years they fell off greatly, in some 
cases to the “ unmanured ” level at once, in others more gradually. 
The residue of nitrogen left by lucerne is still palpable six years 
after the discontinuance of its growth. This year oats have been 
sown instead, and in the oats, leguminous plants again. This will 
shew if the ground has recovered from the “ clover-sickness.” 
Meanwhile the extreme ends of the original “clover-sick” strips are 
still under their impoverished leguminous crops, and wretched 
plants, for the most part, they are. 
Many interesting lines of research that are being carried on at 
Rothamsted cannot be entered into here. No mention for instance 
has been made of the manuring experiments with root crops, nor of 
the investigations which Mr. Hall is pursuing with the object of 
trying to understand that still mysterious property, the “ strength ” 
of wheat, or rather of the dough made from it, a property which 
enables certain foreign wheats, such as American and Russian, to 
fetch substantially more in the market than the best English-grown 
crops. But enough has been written to give some idea of the 
extraordinary botanical interest attaching to the work which was 
begun by Lawes, and which his admirable generosity has made it 
possible to continue indefinitely. A. G. T. 
AN EXHIBIT OF SPECIMENS OF SEED-BEARING 
PLANTS FROM THE PAL/EOZOIC ROCKS. 
rilHE readers of this Journal have been kept informed as to the 
recent additions to our knowledge of the early fern-like 
Gymnosperms. 1 On the occasion of the recent conversazione held 
by the University of London on the 27th of May, a considerable 
collection of specimens was brought together by the chief workers 
in this field, illustrating not merely the newer work, but as far as 
possible also the habit and appearance of the palaeozoic plants 
known to bear seeds or seed-like structures. 2 
In view of the fact that a new group, the Pteridospermeae 
1 New Phytologist, Vol. II., p. 73; Vol. III., pp. 32 and 102. 
2 The following sent contributions :—Mr. E. A. Newell Arber, 
Miss M. Benson, Mr. R. Kidston, F.R.S., Professor F. W. 
Oliver and Dr. D. H. Scott, F.R.S. 
