168 THE INSTABILITY OF LKAF-MOKPHOLOGY, 



2^ inches long, witli intermediate examples showing an extensive 

 range of variation in form and size, are now exhibited. Speci- 

 mens of Xan^Aosia /^i^os-a Rudge, (Cook's River; A. A. Hamilton; 

 April, 1915) show variation in the leaves from ^ inch to 1| 

 inches in length, and from 2 lines to | inch in width; thev are 

 almost sessile, or on petioles up to | inch long, and have a 

 tomencum ranging from pale grey to dull brown. Two specimens 

 of the well known Actiiiotu.s Helkmthi Labill., are exhibited, 

 to illustrate the effects, on the foliage, of bad drainage. 



COMPOSITiE. 



The leaves of Brachycome diversifolia Fisch., ife Mey., and 

 those of B. stricta DC, both range from simple to pinnatifid, 

 many examples of these species being inseparable on the foliar 

 characters. The radical and cauline leaves of most of the Brachy- 

 comes, and many other herbaceous composites, are differently 

 shaped. The minute, clustered leaves of Olearia Jiorihunda 

 Benth., and 0. lepidophyUa Benth., sliow similarity; while their 

 ubiquitous congener, 0. ramulosa Benth., has numerous forms. 

 Of the latter, Bentham (4; iii., p. 477) says, "There are two 

 principal forms, which are often distinguished as species, but 

 only differ in the shape of the leaves." Specimens of 0. myrsin- 

 oides F.V.M., were exhibited before this Society (13; 1914, p. 159) 

 showing leaf- variation due to environment, in dimensions, tex- 

 ture, and length of petiole; and it is now noted that the toraen- 

 tum varies within this species, from dull red to silvery-white. 

 Leaf-variation resultant from seasonal growth, was illustrated 

 in a series of specimens of Cassinia aculeata R.Br., (13; 1915, 

 p. 209); and three forms of C. longifolia R.Br., from Blue 

 Mountain localities, showing leaf-variation, were exhibited (13; 

 1915, p. 722). A change in the xerophytic, protective character 

 from hairiness to viscidity, adopted by an old bush of Helichry- 

 sara semipapposum DC, was noted (13; 1915, p. 289), young 

 plants in its vicinity, evidently its progeny, retaining the pilose 

 character. Mr. J. H. Maiden (15; p. 18) notes three forms of Heli- 

 chrysum rosmarhiifolium Less., var. thyi'soideiim, at different 

 elevations on Mt. Kosciusko, the leaves vai'ying in size, thick- 



