138 Excursion to Werribee Gorge-. [vorxxx 



then keep up right-hand slope, and just above the selvedge of 

 Acacia niontana a dump will be found, and a drive that was put 

 into the glacial for gold. 



(10) Brittlebank (see reference) states that neither " Stringy-bark " nor 



Prostanthera is found growing on the granite, but that the latter 

 abounds in dense growth on the Ordovician and a stunted form 

 of the former makes a dense forest on the poorer slate country. 

 The granite is thinly covered with Casuarina, Yellow Box, Banksia, 

 and Blackwood. 



( 1 1 ) A coach leaves Bacchus Marsh railway station for Myrniong daily 



on arrival of early Melbourne train. This passes gate to track 

 mentioned. Picnic parties may arrange with Messrs. Wills and 

 M'Vicar, of Bacchus Marsh, for conveyances. 



Formations. — East of Gorge generally the surface is Glacial, of 

 Permo-Carboniferous age. 



At Picnic Point and in one or two other places it is overlaid by Volcanic, 

 and is penetrated in at least one place by a porphyry dyke. Many of 

 these dykes may be seen in the Gorge ; they are older than the Glacial. 



The folded rocks are Ordovician (often, however, called Lower 

 Silurian), and are older than the bed-rock of Melbourne, which is Silurian. 

 Falcon's Lookout and Daintree's Cliffs are capped with Glacial, while 

 the railway runs on Newer Volcanic. This overlies a Tertiary formation, 

 which crops out between the line and the place marked on the map as 

 " Bald Hill " (not to be confused with the site of the quarries, some 

 miles away). This deposit is referable to the same age as some of the 

 " red sands " of the south coast and Melbourne areas. 



The Gorge itself has been carved since the flow of Newer Basalt, and 

 in point of age compares with the valley of the Yarra between Fairfield 

 Bridge and Queen's Bridge. 



References. — Many papers have been written dealing with this inter- 

 esting locality. The following are some that may interest the general 

 reader who desires to pursue the subject : — 



1. A list. Assoc, for Advancement of Science, vol. v., 1853 — Paper by 



Brittlebank and Sweet. 



2. Pfoc. Royal Sac. Vict., 1892-3 — Papers by Officer and Balfour. 



3. Supplement to Education Gazette and Teachers' Aid, 21st May, 1906. 



(This is a description in popular language, quite free from 

 scientific terms.) 



4. The Victorian Naturalist, June and December, 1894, and January, 1908. 



5. Monthly Geological Progress Report, May, 1899 — Map only, by 



Brittlebank^— A. L. S. 



A Unique Plant. — The Couniry-Sidc (London) for Novem- 

 ber gives an illustration of a unique plant which has been in 

 the succulent house at Kew Gardens for nearly fifty years. It 

 is a member of the pine-apple family, and attracts considerable 

 notice on account of its silvery yet forbidding aspect, the 

 white leaves being armed with strong tooth- like spines as firm 

 as iron. The plant has not changed for the last thirty years, 

 except that every ten years or so it has flowered. Its unique- 

 ness arises from the fact that it is the only example of the 

 plant known, either wild or in cultivation, and as it shows no 

 incHnation to produce offsets or mature seed, it seems likely to 

 remain the sole representative of its kind in the world. 



