4 o6 SCIENCE PROGRESS 



Taxonomy. — Small (New Phytologist, 191 7) gives an his- 

 torical resume of the views which have been held regarding the 

 taxonomy and interrelationships of the Compositce, in which 

 connection he emphasises the great value of the work of Cassini. 

 The view taken is that the Senecionece are the primitive group 

 from which the tribe of the Chichoriece have arisen. 



Morphology. — M.M. Lignier and Tison (Bull. Soc. Bot. Fr., 

 1 91 3) described an abnormal flower of Gnetum scandens and 

 from its structure concluded that the normal female flower of 

 this genus probably represents a simple, perhaps compound, 

 axis provided with two nodal cupules. This axis is terminated 

 by a plurilocular ovary (the innermost envelope) enclosing a 

 single orthotropous ovule. The late Prof. Pearson has dis- 

 cussed their results, and summarises the evidence as to the 

 morphology of the female flower (Trans. Roy. Soc. S. Africa, 

 191 7). He concludes that : the two outer envelopes are homo- 

 logous with the capsule of the spike ; the innermost envelope 

 probably consists of a modified leaf-pair homologous with the 

 capsule, and the axis of the flower is homologous with that of the 

 spike. In other words, the spike and female flower are modifi- 

 cations of the same primitive structure, which may have con- 

 sisted of a terminal nucellus surrounded by a single ovular 

 envelope followed by a ring of male flowers and one or more pairs 

 of modified leaves. The ovule and the innermost envelope 

 are regarded as strictly homologous throughout the group and 

 the resemblance of the protective structures to the perianth of 

 Angiosperms as not indicative of phylogenetic relationship. 



Ecology. — Mr. W. R. B. Oliver contributes to the Transac- 

 tions of the New Zealand Institute (vol. xlix.) an instructing 

 account of the vegetation of Lord Howe Island. The soil is of 

 two types, viz. that of the limestone area, which is sandy and 

 dry, and a moister volcanic soil rich in humus. The total 

 recorded species of vascular plants number 209, of which 70 are 

 endemic. Of these latter one-quarter are related to New Zea- 

 land species and about one-sixth to those of Australia. Several 

 well-defined formations and associations are recognised. Of 

 these temperate evergreen river forest occupies the largest area 

 and occurs from sea-level up to 300 metres. It is either domi- 

 nated by Ficus columnaris or Acicalyptus Fullagaris, both of 

 which trees have " plank " buttresses to their trunks and leaves 

 with thick cuticle and aqueous tissue. Below the arboreal 



