THE BOTANY OF A COAL MINE. 
By WILLLAM CABEUTHEKS, F.L.S. 
I T is the practice to speak of the known plants of a particular 
geological period as a Flora, but the use of the word is apt 
to convey a very erroneous impression of the extent of our 
acquaintance with the plants that actually existed during the 
time that the rocks of the period were being deposited. No 
stranger would venture to designate the description of a hundred 
of our more common plants, collected during a visit of a few 
hours to our shores, as a “ British Flora.” He may have 
diligently employed his opportunities, and collected an unusually 
large number of species in the short time at his command, but 
at the best they would only be contributions to the greater work. 
One expects to find in a Flora some approach to a description of 
all the species found in the country. 
The list of plants which constitute the Coal Flora has been 
considered as giving a fair representation of the vegetation of 
that period, but a little reflection will convince us, that from the 
nature of the case only a small proportion of the plants then 
flourishing could have withstood the numerous agencies which 
produced their destruction. The chief of these agencies was water. 
The roof shales, in which have been preserved the great propor- 
tion of the determinable remains of the plants, were mud deposits, 
and the water which deposited this mud must have saturated the 
loose vegetable matter below. Water speedily breaks up and 
destroys vegetable tissues, reducing them in the end to an 
amorphous pulp. Lindley has by experiment shown that all 
plants do not yield in an equal degree to this influence. He 
placed 177 specimens belonging to various natural orders into 
a vessel of fresh water. At the end of two years 121 had 
entirely disappeared, and of the 56 that remained, the most 
perfect specimens were those of Coniferse, Palms, Ferns, and 
Lycopodiaceas. It follows then, that a varied vegetation placed 
in the conditions under which the coal beds were formed 
would leave no recognisable remains, while they nevertheless 
might contribute greatly to the amorphous coal mass itself. 
The record of the Flora of the coal measures is further 
