PACHYTHECA 293 



summed up, saying (July 6, 1888), * Your own note in the 

 Quarterly Journal for 1853 contains after all the pith of the 

 matter and the best figure.' 



He would not rest content, however, without having a 

 thorough microscopic examination of the material, old and new, 

 made by a young botanist of Christ's College, Mr. C. A. Barber, 1 

 a capital artist, who in the course of drawing, made out a 

 new feature which Hooker suggested might be callus plates. 

 A doubtful specimen which he showed to Professor Bayley 

 Balfour 2 had yet more doubtful signs of attachment, as of a 

 marine alga, which, if substantiated, might suggest, as the latter 

 said, the possibility of Pachyiheca being a gemma which had 

 been detached from a highly organised Alga. But there was 

 nothing to bear out this suggestion ; and other suggestions as 

 to its affinities based on exact but limited knowledge of some 

 one class were unacceptable to wider knowledge. 



Pachytheca gets more and more inscrutable [Hooker 

 writes to Mr. La Touche on Aug. 3, 1888]. My impression 

 still is that it is in all probability a type of structure of 

 which there is no existing type and of such structures there 

 must have been thousands of old. Uniformitarianism has 

 run mad in Geology and Palaeontology and every dead thing 

 is screwed into the category of living things. I always ask 

 what proofs have we that what are now land shells were 

 not (in their primitive types) sea shells, and vice versa in a 

 more or less degree. But this strikes at the root of all 

 Geology as founded on Palaeontology. 



Accordingly, after tracing the history of Pachytheca and 

 the theories about it, he wound up his paper by declaring that 

 no certain conclusions as to its real nature and affinities were 

 as yet possible. 



His judicial caution was justified. 



1 Mr. C. A. Barber, assistant to (Sir) F. Darwin at Cambridge, was ap- 

 pointed to the new Agricultural Department of the Leeward Islands in 1891, 

 and in 1898, after three years at Cooper's Hill College, became head of the 

 botanical department for the Presidency of Madras, at Ootacamund. 



2 Isaac Bayley Balfour (6. 1853) was Professor of Botany at Glasgow 1879, 

 at Oxford 1884, and at Edinburgh in 1887, the position so long held by his 

 father, J. H. Balfour. 



