BY L. RODWAY. 33 



■common] y knoMai as beech. The beeches living on the 

 earth in the present day are divisible into two groups — the 

 beeches proper, which live only in the cooler parts of the 

 northern hemisphere, and the southern beeches {Notlio- 

 fagiifi), living only in Fuegia, New Zealand, Tasmania, and 

 South-Eastern Australia. The southern beeches differ 

 from the group found in tJie northern hemisphere mainly 

 by having smaller flowers and very narrow medullary rays. 

 But the common characters are too numerous and close to 

 permit the idea that the two groups had independent 

 origin. Therefore, we must conclude their distribution was 

 once continuous across equatorial regions. The present 

 day beeches require a temperate climate, and from this it 

 has been inferred that beeches of former days must have 

 had a similar constitution. Were this so, it would require 

 a cool climate, or, possibly, continuous veTj higji land from 

 north to south at the time when the two groups were 

 connected. It is possible, however, that the genus included 

 forms adapted to tropical conditions which have since 

 passed away. The neighbouring genus of oak has a typical 

 temperate form in Northern Europe, yet it has a profuse 

 distribution in Mexico and Java, but has been extenninated 

 south of the equator. It would not be any strain on the 

 botanical imagination to reconstruct beech with a tropical 

 continuity. The constitution of a genus as it exists in the 

 present day is usually adopted by palaeontologists as an 

 indication of climatic conditions, but it is very doubtful if 

 this is always reliable. When we find a genus like 

 Thismia — which appeared till the other day to be essentially 

 tropic — with a representative in Southern Tasmania, and 

 there often living at an altitude exceeding 2,000 feet, it 

 makes one think. 



The seeds of beech have thin coats, slightly winged. 

 They are rapidly digested if swallowed whole, become 

 waterlogged and sink if blown into the sea, and are too 

 large to be transpor-ted any appreciable distance by wind. 

 Therefore, we may conclude, whatever their distribution 

 may have been, it must have been along continuous land, 

 or, at least, where but nan-ow straits intervened. We may 

 assume that the beeches of Fuegia were once continuous 

 in distribution with the beeches of North America, and 

 that a long separation has permitted a considerable change 

 in their structure. 



The beeches of Tasmania are remarkably close in struc- 

 ture to those of Fuegia. If we infer they had a like north 

 and south migration, then we must assume they were 

 evolved on a parallel line, which is certainly possible, 

 though it would be a strange coincidence that such in- 



