98 



3. That part which, looks towards the north is narrower, and has closer and denser rings than the 

 other. 



M. Ch. Musset states that the trunks of trees are always flattened in a northerly and southerly 

 direction, and expand in an east and west plane, a fact which he considers quite in accordance with 

 astronomical laws. 



4. A singular uniformity has been observed in the twist of tree trunks. In 990 trees out of every 

 1,000 whose trunks show torsion, the direction of the twist is from right to left. This accords with the 

 direction of the revolution of cyclonic storms in the Northern Hemisphere, and also with that of 

 whirlpools, which the French savant, Jean Brunhes, says almost invariably turn from right to left. The 

 question arises whether in the Southern Hemisphere the torsion of tree trunks has an opposite direction, 

 like the cyclonic motions of the atmosphere in that half of the globe. (A reference, the origin of which I 

 have lost.) 



Another quotation from my old friend, Mr. J. F. Camptell : — 



5. While engaged in architectural pursuits in Britain I had an excellent opportunity of observing 

 Borne of the structural characteristics in the growth of the pine timber trees then used in buildiiig 

 construction. As regards the growth curvatures of the trunks of these trees and the influences that 

 produced them, I found that practically all scantlings cut from the pines of the Northern Hemisphere 

 as seen and handled by me had a dextrorse twist, which I then attributed to heliotropism. Assuming 

 heliotropjism as one of the most potent stimuli to twisting, its effect would or should be somewhat 

 irregular within the tropical regions, but becoming more definite and regular towards the Poles. The 

 pine belt of the Northern Hemisphere has practically no counterpart in the Southern Hemisphere owing 

 to the absence of land surfaces of any extent south of lat. 40. But specimens of, say the South 

 Patagonian pines, should aid in elucidating this interesting subject of inquiry. 



10. BARK REPAIR. 



The following species possess the power, in a high degree, of bark-repair if a 

 portion be removed from the trunk. The injured bark will also spread, or tend to 

 spread, over any foreign body adjacent : — E. maculata, E. hcemastoma, var. micrantha, 

 E. tesselaris, E. coriacea. (Angophora lanceolata is an even better example, perhaps.) 



It will be observed that all these are true Gums, or Smooth-barks, in other words, 

 barks that are full of life, not those which are more or less dead superficially, such as 

 Stringybarks and Ironbarks. 



In the case of explorers' and surveyors' marks, a good deaLof inconvenience is 

 sometimes caused by the over-growth of the bark, which may completely obliterate the' 

 inscriptions. 



Callus is the name given to the soft parenchymatous tissue which forms over 

 any wounded or cut surface of a stem. The callus forms a cork cambium on its outer 

 surface. The subject of the growth of the callus over an old wound is dealt with in a- 

 lucid manner (with illustrations) by Professor B. E. Fernow in Circular No. 16 of the 

 Division of Forestry, United States Department of Agriculture. 



In Mr. R. T. Baker's exhibit of a series of specimens showing traumatic growth 

 in timbers, before the Royal Society of New South Wales, 1st September, 1919, he 

 verbally made the suggestion that Kino flow (in Eucalypts) and the formation of Alumina 

 succinate (in Orites excelsa) id&j have an antiseptic action, thus promoting new growth. ■ 

 This is, of course, an analogy to Listerism in surgery. 



