524 EVOLUTION OP THE KUCALYPTS, 



seen, all the far inland species are of one or other of these types. 

 E. pendula has the smallest, bifid cotyledons of all, yet has proved 

 itself most eminently adapted to the dry interior of Australia, 

 being found in New South Wales, Queensland, Victoria, South 

 Australia, and Western Australia. The same is also true of E. 

 uncinata and E. oleosa^ also of this class. 



Not only have the Eucalypts altered the cor?/??i6osa-cotyledon, 

 but they have also changed from the urn-shaped fruit of that 

 group, with its deeply enclosed valves, and contracted neck. It 

 must have been found that the winged prolongation of the testa 

 caused a difficulty in the exit of the seeds, on the opening of the 

 valves. Accordingly, as evolution proceeded, the appendage was 

 abandoned (in E. corymhosa itself, it has almost vanished), the 

 everted rim was cut out, and the valves became higher and 

 higher, till the ovary became quite domed, and the valves 

 exserted after dehiscing. Thus the ready exit of the seeds was 

 provided for. 



Seed was obtained, from Mr. Staer, of E. eudesmioides, a 

 member of the small group of Eucalypts found in North- Western 

 Australia, which Robert IJrown proposed to raise to generic rank 

 under the name Eudesmia. The cotyledons of this species proved 

 to have well marked emargination, with divergent lobes. The 

 leaves were petiolate, opposite, and covered with glandular hairs. 

 So although the opposite leaves, notched calyces, and peculiar 

 stamens indicate cliaracteristics of the early type of Eucalypts, 

 the well marked emargination shows that they have undergone 

 great evolutionary advance in that respect. Hence, in the former 

 characteristics, they may have undergone a reversion to the 

 earlier type, just as we see the same in the urn-shaped fruit of 

 E. urnigera. 



To sum up, then, the evidence of the seedlings of the Eucalypts, 

 and especially of their cotyledon-leaves, agrees with the theory 

 set forth by Messrs. Baker k Smith, based on their botanical and 

 chemical results, that th^^ Corymbosas are the most primitive 

 group of the genus. Later chemical and botanical knowledge, 

 and now the new light thrown by the cotyledons, will necessitate 

 a recasting of the genealogical tree in "A Research on the 



