PREFACE. 
He might, however, have been compelled to delay for years the 
preparation of this Work, but for the circumstance that his connexion 
with the Yorkshire Philosophical Society placed at his disposal probably 
the most perfect herbarium of Yorkshire Plants ever formed, comprised 
of the united collections of three most eminent Botanists, — James Back- 
house, Esq. of York; the Rev. James Dalton, of Croft Rectory; and 
W. Middleton, Esq. of Poppleton Lodge ; and augmented by additions 
of rare species by the Rev. W. Hincks, who commenced a complete 
arrangement of the whole according to the Natural Orders. 
No sooner had he declared his intention of preparing a general 
Catalogue of Yorkshire Plants, than the Author received from Mr. 
Hincks and Professor Phillips immediate and valuable aid. To the 
latter the reader is indebted for the preliminary essay ; and the former, 
besides revising the Work as it proceeded, till his removal from York, 
prepared with great labour an original and valuable Series of Analytical 
Tables, expressly adapted to the Natural Orders of British Plants, 
which nothing but the cost of printing has prevented the Author from 
prefixing to this volume. 
The Philosophical Institution of Sheffield, by giving free access to 
the well known herbarium of Mr. Jonathan Salt, and other collections, 
materially assisted the Author’s views ; and a similar acknowledgment is 
due to the Hull Literary and Philosophical Society. To Mr. S. Gibson, 
of Hebden Bridge, the Catalogue is under great obligations, not only 
for the free communication of his discoveries, especially in Cryptogamic 
Botany, but also for his attention to the general completeness of the 
Work. 
To Samuel Hailstone, Esq. of Croft House, Bradford, the Author is 
grateful for abundant information, specially regarding the Plants of Thorp 
Arch and Craven, and still more for the benefit of his unrivalled know- 
ledge of Rubi, Roses, &c. 
For extensive Lists of Plants observed growing in particular districts 
