HIS WRITINGS 145 



title-page as Director of Kew. But the preface is dated May i, 

 1838, from Glasgow, and it was printed at the University Press. 

 The title-page further states that the plates were from the 

 drawings of F. Bauer, but Sir Joseph Hooker points out {I.e. 

 p. cviii), that "of the whole 135 genera depicted I think that 

 78 are by Fitch." Sir William in the preface states that "The 

 plates have all been executed in my own residence, and under 

 my own eye, in zincography, by a young artist, Walter Fitch, 

 with a delicacy and accuracy which I trust will not discredit 

 the figures from which they were copied." The result is 

 one of the most sumptuous volumes in illustration of a 

 single family ever published. After 70 years it is still the 

 natural companion of all Pteridologists. At its close is a 

 synopsis of the genera of ferns, according to Presl's arrange- 

 ment, which Sir William describes as "the most full and com- 

 plete that has yet been published." But in the preface he 

 remarks that Presl "has laid too much stress on the number 

 and other circumstances connected with the bundles of vessels 

 in the stipes, which in the Herbarium are difficult of investi- 

 gation." This is a specially illuminating passage for us at 

 a time when anatomical characters are becoming ever more 

 important as phyletic indices. It shows that readiness of 

 diagnosis was for him a more important factor than details of 

 structural similarity. 



In the preface to the Genera Filicum Sir William says, he 

 "would not have it to be understood that the Genera here intro- 

 duced are what I definitely recommend as, in every instance, 

 worthy of being retained.... A more accurate examination of the 

 several species of each Genus, which are now under review in the 

 preparation of a Species Filicum, will enable me hereafter to 

 form a more correct judgement on this head than it is now in 

 my power to do." The five volumes of the Species Filicum 

 thus promised, appeared at intervals from 1846 to 1864. The 

 work is briefly characterised by Sir Joseph as consisting of 

 "descriptions of the known Ferns, particularly of such as exist 

 in the Author's Herbarium, or are with sufficient accuracy 

 described in the works to which he has had access, accompanied 

 by numerous Figures. This which will probably prove to be 



o. B. 10 



