442 



NATURE 



[Septkmukk 5, 1S95 



invented by Nicol. This work laid the foundation of our 

 knowledge of the structure of the Lcpiilodcndra and 

 Stii,marhF, and Brongniart then applied the new method, 

 with the most brilliant success, to the investij^.ation of 

 Sigillaria. Williamson also soon attained brilliant re- 

 sults by its aid, studying the shells of Foraminifera, and j 

 the scales and teeth of tishes. Two papers, published in 

 the Philosophical Transactions (1849 and 1851), and con- 

 sidered excellent by competent judges, were the result. 



Naturally, the study of fossil plants, which had been 

 so successfully begun, was not neglected, whenever such 

 material could be obtained in the proper state of pre- 

 servation, which at that time was not easy. Williamson's 

 first attempt of the kind, the precursor of the whole 

 pateobotanical literature which he created, was the 

 paper "On the Structure and .Affinities of the Plants 

 hitherto known as Stcrnhergiir^' in which the Stern- 

 hcr-^'ir were identified as medullary casts, which had 

 been surrounded by an Araucarian wood. .\s already 

 mentioned, however, the material for an extended use of 

 the method was at that time still wanting. Then, just 

 at the right moment, came the discovery of the calcareous 

 nodules, enclosing vegetable remains, in the Canister 

 beds of the coal-fields of Lancashire and Yorkshire. The 

 investigation of the treasures thus revealed was first 

 taken in hand by their discoverer, Binncy himself, and 

 subscciuently by Carruthers and Williamson. The latter 

 first bega:n with works on the Calamarieic. three of which 

 appeared in rapid succession from 1S69 to 1871. They 

 are : " On the structure of an undescribed type of Ca/a- 

 modcndron from the upper coal-measures of Lancashire"; 

 "On a new form of Calamitean strobilus" ; and "On the 

 organisation of an undescribed verticillatc strobilus from 

 the lower coal-measures of Lancashire." 



As was necessarily the case, material now began to 

 accumulate in Williamson's hands, and he enjoyed the 

 active co-operation of various zealous collectors. Then, 

 in his fifty-fifth year, he began the great series of memoirs 

 which mark the culminating point of his scientific activity, 

 and which will assure to him, for all time, in conjunction 

 with Hrongniart, the honourable title of a founder of 

 modern I'alitobotany. 



In the course of the following twenty years, nineteen 

 memoirs of this series appeared in the Philosophical 

 Transactions, under the general title " On the Organisa- 

 tion of the Fossil Plants of the Coal-measures." They 

 all contain exclusively his own observations, made entirely 

 on material from the British coal-fields. It is a gigantic 

 work, which by itself alone would form the abundant 

 fruit of a man's whole life. It was supplemented, how- 

 ever, by various other contributions to the same subject, 

 published in the Memoirs of the Literary and Philo- 

 sophical .Society of Manchester, the Annales des Sciences 

 miliirelles, and the Annals of liotany. During the 

 same period, in 1887, also appeared Williamson's ex- 

 haustive " Monograph on the .Morphology and Histology 

 of Stii^mariit Jicoides" which will long form the basis of 

 our knowledge of these fossils. 



The recognition by paleontologists and botanists of 

 the full importance of these works of Williamson's, 

 has been of course a slow and gradual process. This 

 was really due to external circumstances. In the first 

 place, Williamson found it necessary, as the material in 

 his collection, and his own experience increased, to return 

 rep<Miedly in his later memoirs to plant-remains which 

 had been dealt with in the earlier parts. Consequently, 

 if «'• •••i- h to obtain an idea of any group, it is always 

 nc Hidy several of ihesetreatiscs simultaneously. 



Til r. presents great clilficulties, except to those 



wh separate copies. For the re.ider stands 



heii "• a pile of sixteen volumes of the Philo- 



sopin II I r.iiisaclions '. 



On the other hand, there is another point which must 

 be taken into account. Williamson's method of anato- 



NO. 1349. VOL. 52] 



mical description, clear as it is, bears the stamp of tlu- 

 scholastic ideas of a past time. For this reason it is only 

 understood with difficulty by the botanists of the present 

 day, and must often first be translated into the form now 

 customary. This is laborious, and has stood greatly in 

 the way of the rapid difl'usion of his results. 



Williamson himself was fully conscious of these draw- 

 backs, and finally, in order to remedy them, he began a 

 new series of memoirs, in conjunction with Dr. Scott, 

 the object of which was to present a connected and 

 systematically-ordered account of the results obtained, 

 clothed in the language of modern anatomy. The first 

 memoir of this series appeared in 1895, in the Philo- 

 sophical Transactions, and treats of the Calamariea: and 

 Sphenophyllea:. Two further papers are already com- 

 pleted, Init he was not spared to see them published. 



The basis of all Williamson's labours in fossil botar.y 

 is, of course, the collection of slides which he left, con- 

 taining some thousands of preparations. It is unique of 

 its kind in the world, and of the greatest importance, 

 for it contains the evidence for all the innumerable 

 special observations recorded in his works. Like Will- 

 denow's herbarium or Lindlcy's collection of orchids, it 

 will always remain an invaluable source of information, 

 to which pahuontologists from all sides must resort. lis 

 owner was aware of this, and so also is the autlior of 

 this notice, who may boast that he knows the collection 

 as scarcely any one else does. It was through him 

 that Williamson decided to prepare and distribute, in a 

 printed form, a detailed index, giving exact references 

 to the individual preparations, and the places where they 

 are cited in the memoirs. This was necessary, for the 

 multitude of preparations often made it very laborious, 

 even for the owner, to look out a particular section to 

 demonstrate some special fact. This work was taken in 

 hand about 1890, and has considerably increased the 

 usefulness and value of the collection to posterity. Three 

 instalments, and those the most important, have already 

 appeared under the title, " (jcneral Morphological and 

 Histological Index to the .-Vuthor's Collective Memoirs 

 on the Fossil Plants of the Coal-measures." Only the 

 Cordaite;e, the C.ynmospcrmous seeds, and a number of 

 fossils of doubtful affinity, are still wanting. We may, 

 no doubt, ultimately look for a synopsis of these from 

 the hand of a friend, so as to complete the entire work. 



If we now consider the contents of the pakeobotanic'al 

 literature created by Williamson during the last twenty- 

 five years of his life, we find that it consists, first of all, 

 of the most minute description and reconstruction of all 

 those types of plants which took part in the formation 

 of the coal-beds of Oeat Britain. He abstained on 

 principle from concerning himself with non-British 

 material. We have acquired from him the most exact 

 knowledge of the structure of the Calamarie;e, the Lepi- 

 dodendrca-, the Sphenophyllc;e, the Ferns, and Lygino- 

 dcndreu'. .\s regards several of these groups, it is true, 

 he had before him fairly detailed investigations by 

 previous observers, but in other families, especially the 

 Calamariea^ and Lepidodendrea', he himself laid almost 

 the whole foundation of our knowledge. He showed 

 that both groups are, as regards their fructifications, 

 indubitable .Xrchegoniata-, but that they possessed, like 

 our recent Ciymnosperms, a secondary formation of wood 

 from a cambium ; he taught us to recognise, in the 

 Stigmariiu, the subterranean organs of the Lepidodendrea; 

 and Sigillaria- ; he reconstructed in the genera /. I'.C'""- 

 dendron and Metcrani;iiim, described by him, a t\pe of 

 plant which, by its characters, occupies an intermediate 

 position between Filicinex- and Gymnosperms, especially 

 Cycadfiu. It thus can find no place in the system of 

 recent plants, but represents a direct derivative of the 

 unknown ancestral stock from which the two groups still 

 living have also sprung. In connection with this type, 

 Kenault's Poroxyle:e have since tmncd out to be their 



