278 PROCEEDINGS OF SECTION' D, 



These are mainly Piperacece, as Peperomia leplusiachya, Hook, et. 

 Arn., P. reflexa, A. Dietr., and the newly-discovered P. affmis, 

 Domin ; Crassulacece as Tillia ver icillaris, D.C, T. recurva. Hook., 

 and in places the naturalised African plant Bryophyllum calycinum, 

 Salisb. Rarely the shrubby urnbeUifer, Siehera linearifolia, Benth., 

 is found on the edges of precipitous cliff, as are also Dendrobium 

 kingianwn, Bidw., and the ferns Polypodmm rigidulnni, Sw., and 

 NotholcBna distans, R. Br. 



10. Conclusion. — These tablelands, together with the Laming- 

 ton Plateau at the head of the Logan River, should have been kept 

 as beauty spots and health resorts for all future generations. To 

 Tambourine, Beech and Springbrook Mountains, roads have been 

 constructed, with some very stiff gradients, but still available for 

 wheel traffic. Unfortunately, much of the land on these table- 

 lands is alienated. The State has not done for them what New 

 South Wales has done for the Blue Mountains, and visitors have to 

 depend on boarding-houses and farmhouses for accommodation, 

 and on their own bushmanship for guidance. The Lamington 

 Plateau is still unahenated, and it is to be hoped that this natural 

 botanic garden, the home of a true beech, Fagus Moorei, F. v. M., 

 and many other rare plant forms, may be reserved as a National 

 Park for all future generations of tourists and naturalists. 



8.— GROWTH, DEVELOPMENT AND LIFE-HISTORY IN THE 



DESMIDIA CE.'E. 



By G. I. PLAYFAIR. 



Degeneration in type, the great law of Desmid life. — 

 Among the Desmids there is not to be found that steady 

 upward growth to sexual maturity and onwards to perfection of 

 form which is characteristic of the higher orders of plants. Their 

 life-history discloses a perpetual struggle between the forces that 

 make for the multiplication of cells as against those that tend 

 towards the perfection of the individual, and in this struggle the 

 former are generally triumphant. Degeneration of type, that is 

 to say, holds sway over their life rather than development. 

 Beginning life perfect by development of the zygospore, multitudes 

 of individuals are produced by a rapid process of quickly- repeated 

 cell-division at the expense, as regards size, form and ornamenta- 

 tion of the original and more or less of every succeeding type. A 

 species, therefore, might be described as the sum total of all the 

 forms resulting from any given zygospore by a conflicting process 

 of degeneration^ and development, were it at all certain that only 

 one zygospore is concerned. (See under Zygospore.) 



1 Degeneration here and throughout this paper is not used in any specialised sense, but as 

 the most convenient word to express the degradation of type (as regards size, shape, and ornamenta- 

 tion) in cells produced by quickly repeated cell-division. 



