581 



OBSERVATIONS ON THE TERTIARY FLORA OF 

 AUSTRALIA, WITH SPECIAL REFERENCE TO 

 ETTINGSHAUSEN'S THEORY OF THE TERTIARY 

 COSMOPOLITAN FLORA. 



Part II. 



On the Venation of Leaves and its Value in the Deter- 

 mination op Botanical Affinities. 



By Henry Deane, M.A., F.L.S., &c. 



(Plates xxxv.-xxxviii.-xxxviii. bis.) 



If a botanist, visiting a part of the world hitherto unexplored 

 and failing to find the flowers or fruits of the plants occurring 

 there, were to content himself with collecting leaves and there- 

 upon to proceed to classify his specimens in natural orders and 

 genera and to give them specific names, what would be thought 

 of him 1 He might have ardently devoted himself to the task 

 of collecting, have exposed himself to hardships and dangers in 

 so doing, and he might have spent months or years at the work 

 of classifying and describing his collection, and publishing his 

 results, but in the end what would be the value of all his labours 1 

 To say the least of it, he would only earn ridicule if he were spend- 

 ing his own money; if, on the other hand, his expenses were pro- 

 vided by others, he would bescouted as an impostor, and he would 

 run great risks of being put either into a gaol or a lunatic asylum. 

 Yet it is difficult to distinguish this method from that adopted 

 for the most part by palaeontologists in dealing with fossil leaves. 

 It is very rarely that fruits are found, and when they are, the 

 structure is to a large extent obliterated, so that leaves are almost 



