Physiologie. — Palaeontologie. 121 



eines Lichtblattes durchschnittlich 0,1385 g., das eines Schatten- 

 blattes 0,0717 g. An einem eingeklemmten Baum betrugen diese 

 Grössen: 6710 bezw. 12,08 qm., Durchschnittgewicht eines Blattes 

 (natürlich nur Schattenblätter) 0,090; unterdrückter Stamm: Zahl 

 der Blätter 3145, Oberfläche 8,62 qm. etc. 



Das Blattgewicht in °/ des ganzen Baumes ausgedrückt beträgt 

 in diesen drei typischen Fällen: 2,4 bezw. 1,7 bezw. 1,4. 



Neger. 



Armitage, R. W., Notes on the Occurrenceof Plant Re- 

 mains in Olivine-basalt, Clifton Hill Quarr y. (Victorian 

 Naturalist. XXVII. p. 21-30. pls. 3-4. Melbourne 1910.) 



The paper first gives a useful summary of the records of the 

 inclusion of plant remains in igneous rocks from all parts of the world. 

 These are few because the phenomenon is rare. The communication 

 then records the only instance hitherto discovered in Australia, 

 of plant remains actually included in an igneous deposit. The speci- 

 men was a piece of wood 3 ft long and 7—9 inches in diameter, 

 and not only entirely enclosed by the basalt, but permeated by 

 "miniature dykes and sills of basalt" which had flowed into the 

 shrinkage cracks along the medullary rays and around the annual 

 rings. The wood is carbonised, but has suffered no further change 

 than a slight pyritization. The age of the basalt is supposed to be 

 Newer Pliocene. The wood has not been finally determined, but 

 suggests one of the Casuarineae. M. C. Stopes (London). 



Benson, M., New Observations on Botryopteris antiqua, Kid- 

 ston. (Ann. Bot. XXV. p. 1045—1055. pls. 81—83. textfig. 1-2. 

 1911.) 



Specimens from the Calciferous Sandstone of Scotland Supple- 

 ment the incomplete knowledge of this new species, of which hitherto, 

 the mode of departure of the leaf trace from the stele has been 

 unknown. 



The structure of the stele is simple, the stem x}^lem consisting 

 of a mass of primary tracheids with only one protoxylem group 

 placed laterally. The trace separates with an increasing angle of 

 divergence until it lies at an angle of 90° to its plane of attachment. 

 The petiole trace may be monarch or diarch, and the author states 

 that no case has been observed of the stem giving off two consecutive 

 diarch petioles. The monarch traces however are always accompanied 

 by aphlebiae. The author says "we may regard it as fairly established 

 that diarch petioles without any aphlebia occur, succeeded by petioles 

 with a monarch vascular bündle and a monarch aphlebia trace. This 

 contrast between the petioles of B. antiqua is interesting, and pro- 

 bably will prove to indicate some distinction in function to which 

 we have as yet no clue". 



The author considers that the trend of evolution in Botryopteris 

 is towards a multiplication of the protoxylems, and that the monarch 

 type is the older, the diarch being derived from it. 



Pseudo secondary thickening is recorded, in the stem. The 

 author brings forward reasons against Bertrand's view that Bo- 

 tryopteris is a reduced type. M. C. Stopes (London). 



