140 Chapman, The Palceozoic Flora. [v.^"^xxxiv 



A SKETCH OF THE GEOLOGICAL HISTORY OF AUS- 

 TRALL\N PLANTS.— THE PAL/EOZOIC FLORA. 



By Frederick Chapman, A.L.S., (Sic, Palaeontologist, National 



Museum, Melbourne. 

 [Read before the Field Naturalists' Club oj Victoria, loth Sept., 191 7.) 



Introductory. 

 The beginnings of life on the earth is a subject of ever- 

 recurring interest, and plant-life especially presents a fascin- 

 ating field of research. According to ordinary expectations, 

 we ought to be able to trace the early history of plant-life of a 

 period long antecedent to the appearance of animals, but, 

 alas ! the ready disintegration and decay of plant structures 

 has frustrated this hope, and, whereas many surprising dis- 

 coveries of delicately-structured animals, such as bristle- 

 worms and jelly-fishes, have lately been made amongst some 

 of the oldest fossiliferous rocks, the only plants decipherable 

 are of doubtful fucoid origin. In some cases these primitive 

 fossils appear to have a strong claim to be regarded as seaweeds, 

 whilst others — and they are numerous — can with as much 

 certainty be referred to tracks, rill-marks, or even plant-like 

 animals, such as sponges, with dendroid growth ; others, again, 

 show a claim to hydrozoan afftnities. 



Following Lyell's metaphor, Darwin says : — "I look at the 

 geological record as a histor}' of the world imperfectly kept 

 and written in a changing dialect. Of this history we possess 

 the last volume alone, relating only to two or three countries. 

 Of this volume only here and there a short chapter has been 

 preserved, and of each page only here and there a few lines. 

 Each word of tlie slowly-changing language, more or less 

 difficult in the successive chapters, may represent the forms 

 of life which are entombed in our own consecutive formations 

 and which falsely appear to havr been abruptly introduced." 

 As the present poet laureate puts it, we are left to decipher 

 what remains of " Nature's history book, which slie hath torn, 

 as ashamed of." Tliis broken record of organic remains is 

 especially noticeable in the vegetable world, for tliere, besides 

 the inherent delicacy of tissue, the preserving agency of rapid 

 sedimentation, resulting in the exclusion of aerobic bacteria, 

 is often wanting under terrestrial and lacustrine conditions, 

 and only by the merest chance has there occurred a fortuitous 

 happening of events which permitted the remains of ancient 

 plants to be embalmed in the rocks for present-day study. 



In some few cases, however, there has been an \dvd\ pre- 

 servative covering, as in that of leaves in beds of pipe-clay ; 

 and in many instances even the structure of tissues has been 

 preserved, as in the coal-balls of the Yorkshire coalfields. In 



