BY CUTHBERT HALL. 523 



glohilus-type of cotyledon, the larger cotyledons are usually 

 found in the cool mountain-areas. Some of these are E. globulus, 

 E. Maideni, E. unialata, and E. urnigera. This last species 

 shows a peculiar atavistic character in its urn-shaped fruit, thus 

 returning to the corymbosn-type. In the group of very small 

 cotyledons, a great many, such as E. viridis, E. rostrata, E. 

 WooUsiaiia, and E. poli/bractea, are found in the hot, dry interior. 

 In the Peppermint-group, with the exception of E. Planchoniana, 

 which is an aberrant member, a great uniformity of size exists 

 among the cotyledons, and the emargination is slight or may be 

 practically suppressed. When we come, however, to the species 

 found on the higher mountains, such as E. amygdalina, E. dives, 

 E. radiata, and especially E. coriacea and E. stellulata, we find 

 that the cotyledons are considerably reduced in size; this on 

 account of the great radiation, and keen, searching winds of these 

 altitudes. 



As Tasmania has been separated from the mainland for such 

 ages, it is well to review the types of cotyledon occurring there. 

 Those of the globulus-gvouip are E. globulus, E. iirnigera, E. 

 U7iialata, E. vimiualis, E. Gunnii, E. Perriniana, E. cordata, E. 

 Muelleri, E. acervula, and E. Rodwayi, the last having the 

 smallest cotyledons of all. In the Peppermint-group, there are 

 E. linearis, E. phlebophylla, E. Jiisdoni, E. Delegatensis, E. 

 virgata, E. tce.iiiola, E. cocci/era, and E. amygdalina; while in 

 the Stringybark group, we have E. obliqua and E. regnans. The 

 corymbosa- and Y-shaped groups are unrepresented. 



The reason for all this great reduction in the large foliaceous 

 cotyledons of the E. corymbosa-type, will now be evident. In a 

 tropical climate, with fairl}^ abundant rains, these would be the 

 suitable type. But when droughty conditions and an abnormally 

 dry atmosphere, with continuous, searching winds, had to be con- 

 tended against, a reduction in size became necessary, so as to 

 lessen the area of evaporation, and the area of exposure, both in 

 the seed and in the germinating plant. Hence we get the very 

 small, oblong cotyledon, as in E. conica; and the small Y-shaped 

 one as in E. pendnla, or, in a few cases, the very small round or 

 reniform shape, as in E. dumosa and E. inci^assata. As far as 



