244 Reid . — Further Contributions to the 
shall be confined as far as possible to the facts, and to such 
inferences as to former climatic changes as seem to follow 
necessarily from a study of the botanical evidence. Without 
some idea of the prehistoric state of Britain the records 
would be of little value. I doubt whether many, even of 
the geologists, have realized that ceaseless ebb and flow which 
prevents our fauna and flora from exhibiting more than the 
rudest adaptation to the present state of Britain. Possibly 
in some part of the Tropics a balance may have been arrived 
at ; but in Britain the last climatic changes have taken place 
at too recent a date for such a result, and the composition 
of our flora is still undergoing constant modification. 
About one-seventh of our flowering plants have now been 
found in the fossil state. This is by no means a large pro- 
portion ; yet considering that fully a third of our species 
have neither deciduous leaves, woody stems, nor hard seeds, 
and are unlikely therefore to be often preserved as fossils, 
it is not unsatisfactory. The orders are very unequally 
represented. In the first place, annual plants with soft seeds 
are almost entirely absent. Orders such as the Cruciferae 
and Orchideae are wanting ; Grasses are found, but only 
as indeterminable nodes or leaves. These deficiencies are 
easy to understand ; but the absence of Leguminosae and 
of the aquatic species of Veronica and Scrophidaria is less 
comprehensible, and makes one speculate as to whether the 
deficiency is real, or in part due to the more perishable nature 
of the pods and seeds, though these may seem quite hard 
enough to be preserved. The orders best represented are 
mainly those which possess hard fruits or seeds specially 
adapted for dispersal, and those with deciduous leaves. 
Ranunculaceae, Caryophyllaceae, Rosaceae, Cupuliferae, 
Naiadaceae and Cyperaceae are all fairly well represented; 
Umbelliferae are not uncommon, though seldom in a deter- 
minable state. Fruits of Compositae are characteristic and 
do not readily decay ; various species belonging to this 
order have been discovered, but they are usually represented 
by a few wind-borne specimens. The order is likely to yield 
