220 MR. J. STAliKIE OAUDNER ON SOME FOSSIL 



logical, aud not botanical value. "With regard to the supposed 

 PlatanuSj it is quite unlike the real Plaiamis in form, texture, 

 and venation, and perhaps more like some Cretaceous leaves 

 known as Crcdncria and Protopliylhrm. There is no reason to 

 doubt, however, that true Plaianus was already in existence at 

 this period, as it has been found in our lower Eocenes in England, 

 and in still older rocks in America. A curious burr-like fruit, 

 perhaps belonging to one or other of these species, is not 

 uncommon. There are about twenty species of Dicotyledons in 

 all, but I believe ihat further search will greatly increase the 

 number. 



The differences between this flora and those of the County 

 Antrim, which are included in the same Basaltic flows, though 

 on a liighcr level, arc very remarkable. There must have been 

 a considerable lapse of time between them, but the diff*erence is 

 too great to be altogetlier accounted for in this way. Eorests 

 disa2)pear at times with great rapidity, and the arrival of new and 

 vigorous species will sometimes exterminate the indigenous trees. 

 There is the well-known instance in Denmark of the Beech 

 killing off' the Birch, the Oak, and the Eir. A change in the flora 

 does not therefore necessarily imply a fresh geological period. 



There is another and perhaps more ingenious way of account- 

 ing for the change. The enormous flows of basalt must have 

 been continually substituting a Lutcrite formation with a rich 

 and ferruginous soil for the previous gneiss and limestone, and 

 this we may assume would lead to a considerable change in the 

 character of the forests *. A flora may be produced in a sheltered 

 sp^ot of (juite different aspect from the average flora of a locality. 

 Thus no one wandering over the Isle of Mull would suppose 

 that in Bute Island, in almost the same latitude, there are 



* As an oxaniplc of this I mjiy quote from Mr. Kurz, in his preliminary 

 Eeport on the Forest and other Vegetation of Pegu. *'No other formation 

 except motiunorphic and volcanic ones, can boast of such a variety of species, in 

 spite of its apparent sterility, as Luterite. It is tliis rock that affects vegetation 

 so much that tlie great clitTerence between the floras of Malacca, Borneo, 

 Sumatra. &c., on the one hand, and that of Java, on the other side, is produced. 

 It is also this formation which allows so many Australian genera, like Mela- 

 leuca^ BockeUy Tristan'ia, T.cueopogo-n^ &c., to spread so far to the north- 

 west, some of whicli, like 7V/V/«w/f^ spread as far north as the Ava frontier. 

 If all the Laterite plants were to In? ».■ rased from a list of the plants of Pegu 

 proper, the flora woidd be rendered very \niinteresting indeed." 



