220 Professor Williamson on some [Feb. 16, 



WEEKLY EVENING MEETING, 



Friday, February 16, 1883. 



George Busk, Esq. F.E.S. Treasurer and Vice-President, in tbe Cbair. 



Professor William C. Williamson, LL.D. F.E.S. 



On some Anomalous Oolitic and Palceozoic forms of Vegetation. 



In the course of lectures which I have delivered in this hall during 

 the last few weeks I have tried to show the kind and amount of 

 support which the study of fossil vegetation renders to the Darwinian 

 doctrine of Evolution. With such an aim, attention was necessarily 

 limited to plants whose true botanical af&nities appeared to me to be 

 virtually indisputable. This limitation was indisi)ensable, since such 

 plants alone could be admitted as evidence when the question of the 

 pedigree of the vegetable kingdom was in question. Plants whose 

 organisation was obscure, and whose external forms might indicate, 

 with equal probability, relationship to more than one amongst the very 

 different types which appeared during the later developments of the 

 vegetable kingdom, could not be relied upon as witnesses testifying 

 to the facts which actually occurred a- ages rolled by. 



Unfortunately the Palasozoic and Mesozoic strata have furnished a 

 considerable number of such undetermined i)lants. The history of the 

 study of many of these is but too humiliating to scientific men. A 

 considerable number of objects which, beyond doubt, were not vege- 

 tables have had places assigned to them in the history of the plant race ; 

 whilst other very similar, but equally indeterminable forms, may not 

 only have been plants, but as such may have played a very important 

 part in the genetic chain of vegetable life. Such objects must 

 have had an ancestry, and may have had important descendants. Yet, 

 owing to their obscure indications, we can assign to them no position 

 in the story of vegetable ontogeny. It is to a few striking examples 

 of these doubtful objects that I propose calling your attention 

 to-night. 



In Plate II. Fig. 6, and Plate III. Fig. 7, of Young and Bird's 

 ' Geological Survey of the Yorkshire Coast,' published in 1822, two 

 specimens of fossil plants are represented. The former of these speci- 

 mens was regarded by the authors as the fruit of a Cycadean plant, 

 the leaves of which occur in the stratum in which the specimen was 

 found, in great abundance. This stratum is a ferruginous sandstone, 

 one of the subdivisions of the Inferior oolite seen at Runswick Bay 

 and other parts of the sea-coast of north Yorkshire. I obtained 

 numerous specimens of the same objects in 1832 and subsequent 

 years, and I had the opportunity of examining others in the museums 



