BY A. A. HAMILTON. 167 



juvenile and adult foliage. On example 1, a pair of leaves are 

 seen coherent by their margins; the fusion exists along the 

 greater part of their length, and they are, together, little broader 

 than an individual normal leaf; the well-developed midrib of 

 each leaf, and the deeply notched apex, disclose the unity. 



In the hvgrophytic group of this family, the leaf-characters 

 show similarity as a result of the conditions of shade, shelter, 

 moisture, and rich soil, found in the Brush Forest. The pendu- 

 lous leaf, with its long, acuminate, dripping point, a device to 

 throw off superfluous water, which, by remaining too long on the 

 leaf, would interfere with transpiration (23; pi 7) is found in the 

 «' Brush-Myrtles " of the allied genera, Myrtus and Eugenia, and 

 the more distantly related Syncarpia leptopetala F.v.M. The 

 similarity in the case of the "Myrtles'' is enhanced by the glossy 

 coating of the leaves, another factor engaged in expediting the 

 exit of surplus moisture {loo. cit.). The inconstancy of the op- 

 posite versus alternate arrangement of the leaves in the genus 

 Melaleuca, used by lientham in his key to the species (4; iii., 

 pp. 125, 126), as a differentiating sectional character, is a not 

 infrequent source of difficulty to the systematist; and leaf-twist- 

 ing, in certain members of the genus, is not an invariably reli- 

 able character. 



FiCOIDEiE. 



Similarity in the effect produced by the xerophytie conditions 

 obtaining on the beach, is exemplified in the case of the heavy, 

 triangular, succulent leaves of Mesernbryanthemum cequilaterale 

 Haw., and those of the introduced M. edule L., a resemblance 

 doubtless responsible for the deferred detection of the latter 

 species, until quite recently ( 13; 1913, p.396). Both plants are 

 of the carpet-forming type, their heavy, succulent leaves emi- 

 nently fitting them for existence on the shifting sand-dune. 



TJmbellifer.e. 



Examples of some forms of Siebera Billardieri Benth., from 

 Leura (A. A. Hamilton; January, 1915) with leaves from 

 rotundate and \ inch to ^ inch long, to nari'ow lanceolate and 



