TRANSACTIONS OF SECTION C. 683 



is chiefly due to the more careful exploration of the Tertiary strata, in which the 

 more hio'hly organised and consequently more differentiated plant-forms occur. 



The number of plant-remains described in Great Britain during the whole 50 

 years has been extremely small, but much has been accomplished in the study of 

 fossil plants generally, and in this task no one has been more earnest than Professor 

 Williamson, of Owens College, Manchester. 



His investigations of the plants of the coal period have been of the most 

 exhaustive nature, and from his researches into their microscopic structures we are 

 almost as well acquainted with the minute tissues of these ancient denizens of the 

 forests of the Carboniferous epoch as we are with those in the parks around 

 Manchester to-daj-. 



Mr. Carruthers' ' Memoirs on the Coniferaj and Cycadese, and on the Fruiting 

 Organs of the Lycopodiacese ' have greatly advanced our knowledge of these interest- 

 ing types, heretofore but imperfectly known from their fossil remains. 



Mr. R. Kidston has devoted himself most earnestly to the investigation 

 of the fossil plants of our British coalfields, and he has determined not to rest 

 satisfied merely to work out the plants obtained by others in our museums, but lie 

 has visited all "our coalfields and searched the shales on the spot for himself. The 

 results of his collectings may now be seen in the valuable additions made to the 

 coal-measure series of plants in the British Museum (Natural Historj'). 



But it is more especially in reference to the Tertiary flora of Britain that 

 progress has been made of late years. 



Thanks to the labours of Mr. J. Starkie Gardner, who has not only obtained 

 abundant materials for an exhaustive monograph with his own hands from Sheppey, 

 Alum Bay, Bournemouth, Eeading, Mull, Antrim, and many other localities, but 

 has already favoured us with several memoirs in the Palaeontographical Society's 

 annual volumes and elsewhere on the British Eocene flora, we may hope before 

 long to have a more complete history at this period of our islands than we already 

 possess of the flora of the Carboniferous age. 



Nor has an}- research, favoured by the aid of this Association, brought so large 

 a return in beautiful and instructive specimens to our National Museum of Natural 

 flistory as have the investigations carried out by Mr. J. S. Gardner. 



We must not omit to mention Mr. Clement Reid, who has so diligently traced 

 many of the specimens of our existing flora in the Pleistocene strata of the eastern 

 counties. 



' Large numbers of ferns and gymnosperms ' (says Mr. Gardner) ' have been dis- 

 covered in Mesozoic rocks, but remains of the interesting monocotyledons which 

 must have accompanied them are provokingly scarce. V^'e know that palms, 

 grasses, &c., appear at certain definite horizons, but we are ignorant regarding their 

 ancestry. We know that temperate floras, largely composed of dicotyledons, 

 flourished as far north as man has been able to penetrate in the Cretaceous and 

 Tertiary periods, but nothing in the least suggesting a transitional form has been 

 found amongst them. Lastly, we have learnt that floras now indigenous to Japan 

 and the Himalayas, to Australia and South America, once inhabited Europe, 

 groups of wholly different plants succeeding and displacing each other in rajnd 

 succession on the same spot so as to suggest that the normal condition of floras is one 

 of slow but perpetual migration, and that the term "indigenous " has no geological 

 significance.' 



In reference to the question of geographical distribution of organised beings in 

 geological time, the conclusion is strongly forced upon us, from a study of fossil 

 remains, that the great zoological provinces into which the earth's surface and the 

 seas of the globe are now subdivided have been brought about by the limitation of 

 species at no more distant date than the Secondary period, and probably even later 

 than this. 



That in Palaeozoic times there must have been a great uniformity of marine 

 conditions, and the fauna of each of the primary formations was consequently not 

 only of vast duration but of world-wide extent. 



When, as in Carboniferous times, we are enabled to study the contemporary 

 land conditions of the globe, we find they must also have been very uniform, at 



