IS EUCALYPTUS VARIABLE 1 331 



are, variable in many ways. As a matter of fact the 

 anthers refuse to be rigidly marshalled into sections. They 

 sometimes display such variation of divergence of cell, size, 

 and mode of dehiscence that classification on the anthers 

 alone becomes a matter of difficulty. In the old collections 

 the difficulty is enhanced through the partiality of insects 

 for these organs. Nevertheless examination of the anthers 

 is always carried out by me, and it is a most useful 

 character. 



Pollen-grains — Mueller (Eucalypiographia, under E. 

 erythrocorys), has shown that the size of pollen-grains 

 varies in different species, but we require very many more 

 measurements than are available to be in a position to 

 place any interpretation upon the results. The shape of 

 the pollen-grains also varies, but we have few data on the 

 subject. 



Calyx — The calyx, "cupula" of De Oandolle and other 

 botanists, the "hypanthium" of Schauer, is no longer used 

 for classification purposes, having been proved to be so 

 utterly variable. De Oandolle (and his translator G. Don) 

 offered a classification of the Eucalypts consisting of 

 opposite or alternate leaves combined with a comparison 

 of the size of operculum with the cupula. 



Fruit — While many botanists have more or less used the 

 fruit as a diagnostic character in Eucalyptus, and it is 

 undoubtedly the best character we have, it is due to Pro- 

 fessor Tate to say that {op. cit.) he was the first to submit 

 a scheme for classification of the genus based on the fruits 

 alone. He deals with (a) shape; (b) external sculpture 

 and ornament; (c) capsular-teeth; (d) capsule-cells; (e) 

 fertile seeds. But examination of Professor Tate's scheme 

 shows (through no fault of his) how very imperfect and 

 full of exceptions it is. Taking item by item we find the 

 shape in each species to vary within wide limits. Per- 



