The President's Address. By Dukinjield H. Scott. 133 



of the Coal Measures were not simpler, but far more complex than 

 their successors, so the Cycadophyta of Mesozoic age were, on the 

 whole, on a much higher level than the surviving family Cycadaceae, 

 which now represents them. The history of the vegetable king- 

 dom, so far as its records are known, is the history of the ascendancy 

 of a succession of dominant families, each of which attained at 

 some definite period its maximum, both in extent and organisation, 

 and then sank into comparative obscurity, or died out altogether, 

 giving place to some other race, which, under changing conditions, 

 was better able to assume the leading role. The Cycadophytes of 

 the Mesozoic were, in their day (and it was a long one), a dominant 

 group, almost as much so as the Dicotyledons are now, and they 

 equipped themselves with a correspondingly high organisation, even 

 rivalling the Angiospermous Flowering Plants (perhaps cadets of 

 the same stock), which ultimately displaced them. 



Among the Mesozoic Cycadophyta there were some, as already 

 mentioned, which appear to have been essentially similar to our 

 recent Cycads. The genus Androstrohus, for instance, appears to 

 represent male cones not greatly differing from those of the living 

 family. A good example from the Rhsetic of Sweden has lately been 

 described by Professor Nathorst,* and although the pollen-sacs do 

 not quite agree with those of any recent Cycad, the author has no 

 doubt of its affinity. Carpels much like those of the genus Cijcas 

 are also known from various Mesozoic horizons, and it is probable 

 that this primitive type already existed as far back as the Triassic 

 period. There is also evidence, though perhaps less convincing, 

 for the presence of the type of the Zamiese — the Cycads with seeds 

 borne on definite cones — in Ehsetic and Jurassic rocks. Thus we 

 find, as we might expect, that the Cycadacese, as we know them at 

 the present day, are themselves a very ancient race. I do not, 

 however, propose to dwell on this line of descent, but will now pass 

 on to those Mesozoic Cycadophyta which attained a higher level of 

 organisation, giving them a better title to the name of " Flowering 

 Plants " than any of their predecessors or contemporaries. 



The genus Bennettites was founded by Carruthers in 1868 f for 

 certain Cycadean stems, of Oolitic and Lower Cretaceous age, with 

 fruits borne on secondary axes, not protruding beyond the bases of 

 the petioles. The species on which, for many years, our knowledge 

 of the group was principally based, is Bennettites Gibsonianus, 

 of which a magnificently preserved specimen was discovered, just 

 fifty years ago, in the Lower Greensand of Luccombe Chine, in the 

 Isle of Wight. Some years later a second specimen was found in 

 the same locality, but no others iiave as yet come to light. In 



* " Beitrage z. Kenntniss einiger mesozoischen Cycadophyten." Kougl. Svensk 

 Vetensk. Akademiens Handliiigar, xxxvi., 1902. 



t " On Fossil Cycadean Stems from the Secondary Rocks of Britain. Trans. 

 Linn. See. London, xxvi. 



