Bairnsdcde Gravels and Fossil Wood. 17^ 



** This fossil wood is found in the coarse gravel beds which over- 

 lie the limestone and finer drift sands, and which appear to mark 

 the course of the creeks in late Tertiary times. They frequently 

 form the resistant material which has determined the position of 

 the ridges. The fossil wood occurs with pebbles of quartzite, milky 

 quartz and various volcanic rocks. The wood is always rounded 

 and waterworn, and appears to have been petrified in some deposit 

 previous to the one in which it is now found. The pebbles come- 

 from rocks which form the hills northwards from Omeo. Thei-e is- 

 abundance of Yellow Box growing in these hills at present."! 



The general appearance of this specimen of fossil wood is closelj 

 like that of Yellow Box {Eucah/pfys melliodora). Sections were cut 

 in three directions, microphotographs of which accompany these 

 notes. 



Annual rings. — These average about 2 mm. apart in the fossil. 

 In the Yellow Box specimen, before me they average about 2.5 mm. 

 This difference might of course be due to dryness of soil in the case 

 of the fossil specimen, and in any case there is always a large 

 amount of variation even in individual examples. 



Pores. — In the fossil specimen these are thin-walled and rather 

 densely packed. In E .melliodora they are moderately thin-walled 

 and slightly less densely packed. In E .ohliqua (Messmate), the 

 poi-es are large and more dispersed. In E .liemiyhloia (Grey Box) 

 and its variety, alhens. (White Box), the pores are very dense. In 

 E .rec/nans (Mountain iVsh Gum), the pores are large, and more 

 widely dispersed than in the fossil specimen, and the walls are 

 thicker. E. Sieherinji.a (Silver Top) shows a closely similar struc- 

 ture to the fossil in transverse section. In E.macror/iyvcha (Vic. 

 torian Stringy Bark) the pores are less numerous than in the 

 fossil. 



Tangential Section. — The cross sections of the medullary rays in 

 the fossil as compared with E. Sieheriana are shorter and more irre- 

 gularly curved and tapering, whilst it closely agrees with those in- 

 E. melliodora. In E.regnans the fibres are denser and the medul- 

 lary rays more numerous. 



Radial Section. — The bundles of cells forming the rays in the 

 fossil wood are much coarser in structure than in E .hemiphloia, 

 and are exactly similar to those in E.mfllindora. In E.lpur.oxylon 

 and E.regnans the rays are more closely arranged. 



1 This last statement was in reply to a question as to whether Yellow Box was found \n> 



the district. 



