294 RETIEEMENT, TO 1897 : BOTANICAL WORK 

 To Eev. J. D. La Touche 



June 9, 1895. 



I have this morning received from Mr. Murray of Brit. 

 Mus. a notice published in the ' Phycological Memoirs ' of 

 Pachyiheca, which is enough to turn your hair gray if 

 it were not so already ! 



Pachyiheca is found to sit in a cup ! from the base of 

 which cup rootlets issue ! (sketch). The cup has distinct 

 traces of a stalk, and so must have been attached to some 

 large body. Pachyiheca itself of these specimens retains 

 its internal structure but no structure has been found in 

 the cup. They are from S. Wales. 



A more ghastly proof of the futility of speculations on 

 the nature of imperfect specimens could not well be. ' Ex 

 uno disce omnes ' ! 



A letter to Canon Ellacombe, the well-known horticulturist 

 and botanist, illustrates Hooker's experience of the pitfalls 

 of Fossil Botany. 



Dec. 19, 1887. 



Your question is a very difficult one to answer. Fossil 

 Botany has made enormous strides in the matter of publica- 

 tion of names and drawings since 1852, but not, that I am 

 aware, under the hands of competent botanists familiar 

 with the existing flora of the globe or the infinitely varied 

 forms of recent plants, and above all with the incessant 

 repetition of identical forms of foliar organs in the most 

 different natural families of plants. Of certain identifica- 

 tions there can I think be no reasonable doubt, as of the 

 genera Liriodendron and Salisburia * and of a few others 

 where the fruit has been found associated with the foliage, 

 as I believe, of Liquidambar and Platanus, Acer, &c. 



When you come however to coniferous fruits, where to 

 ascertain even the tribe of the recent genera, you should 

 know the position of the ovule, and where the form of the 

 foliage and cone is so polymorphous, I must confess to the 

 gravest doubts. Nor would I accept the evidence of Aihro- 

 taxis, except on the statement of a botanist well versed in 

 recent Coniferae. 



1 Nevertheless no competent botanist would be surprised at receiving from 

 New Guinea or China, plants of totally different Natural Orders showing the 

 foliage of these genera. 



