34 



never be found. One of the great difficulties was the illustration 

 of the fossils. Photographs were impracticable, and yet it was 

 most undesirable that the personality of the artist should exercise 

 any influence or bias. Variation in illumination was requisite 

 to ensure that no structure of importance should pass 

 unobserved. A new type of instrument the Lapworth-Parkes 

 microscope was devised, and this, under the skilled and artistic 

 workmanship of Miss Wood, solved the most difficult problem. 



It was arranged that the Palaeontographical Society's Mono- 

 graph should be edited by Professor Lapworth, that the descriptions 

 should be done by Miss Elles, and in part by Miss Wood, and that 

 the latter should be responsible for the drawings and for writing the 

 critical history of the subject. In this way, year by year, the work 

 was carried on. The eleven parts appeared between 1901 and 1918, 

 and Lapworth had the satisfaction of seeing this part of his life 

 work crowned by a monograph which will rank as the classic 

 work on the subject for many years to come. 



One can easily understand the satisfaction with which he 

 must have regarded the great summary table showing the zonal 

 distribution of the British Graptoloidea, dated 1914, which *" may 

 most simply be regarded as the second and greatly extended edition 



of a combination of Table X and Table XI as 



given in the Memoir ' On the Geological Distribution of the Rhabdo- 

 phora,' 1879-80. *" In the Memoir some twenty Graptolite zones 

 were recognised ; that number has now been increased to 36. 

 In the Memoir some 284 species and varieties of British Grapto- 

 loidea were referred to ; that number has now risen to 372." But 

 if between 1879 and 1914 the work of himself, his students, friends, 

 and imitators, has added but sixteen zones and less than a hundred 

 species in thirty-five years, what are we to think of the work, 

 very largely that of a single man, unaided and ' in opposition/ 

 wrought between 1869 and 1879 ? 



F. THE FOLD. 



It was not till 1892 that Lapworth allowed himself to follow 

 up in wider generalisations the tectonic results to which his study 

 of the works of Rogers, Heim, Suess, Bertrand, and Brogger, and 

 his own observations in regions of highly folded rocks, had led him. 

 In that year he was President of the Geological Section of the 

 British Association at Edinburgh, and gave one of the most striking 

 addresses which has ever been delivered in that Section (48). 



After pointing out that two of the life stages of a Geological 

 Formation, detrition and deposition, have been studied in the 

 light of present-day processes, he advocates that the third stage, 



* 62, p. 514. 



