382 SECTIONAL TRANSACTIONS.— K. 



Plant disease control more promising in horticulture. Margin of profit higher. 

 More labour available. Plant sanitation essential. Prevention better than cure. 



Forestry. 



Prevention of disease in nurseries and inspection and control of importation. 



Dr. William B. Brierley. — 



( 1 ) Scope of Discussion. 



(2) Research Aspects. 



(A) Centres of Research. 



(i) Source, training and supply of men. Financing and staffing of laboratory, 



field and administrative services, 

 (ii) Types of research centres. Gradation from pure to applied work. Uni- 

 versities, research foundations, crop stations, government and extension 

 services, commercial services. Source of moneys and type of centre in 

 relation to scope of work, integration and administrative control. 



(B) Fields of Research. 



(i) Principles of control. Disease surveys ; plant hygiene and sanitation ; 

 plant protection ; escapement of disease ; exclusion of disease. Effective- 

 ness of methods in relation to expense, social, economic and political 

 implications, 

 (ii) Some primary general issues. 



(3) Applied Aspects. 



(A) Popularisation of Knowledge. 



Oral instruction, field service, printed matter. Relative values of the several 

 avenues. 



(B) Application of Knowledge. 



Liaison mechanisms ; official, commercial, institute and extension, ad hoc, 

 personal. 



Comparative values of the several mechanisms in relation to types of knowledge 

 and practice. Suggestions regarding organisation. 



(4) Essential problem for discussion is the integration of practice and research. 



Miss E. Welsford, Dr. M. Wilsom, Dr. W. G. Smith, Mr. W. A. 

 Millard, Dr. Storey. 



Dr. J. P. Lotsy — Demonstration (during the above Discussion) of 

 Natural Hybrids between Plants and between Human Races in New 

 Zealand and South Africa. 



Prof. J. McLean Thompson. — Sterility and Gigantism in the Lecythidece. 



An attempt is made to show that in the Lecythidean Myrtles a marked advance 

 in sterility has occurred, and may still be in progress. It has affected in particular 

 the androecium which has been transformed progressively into massive and sterile 

 tissue which is in part glandular and in part petaloid. The latter part is marked by 

 pronounced cellular gigantism, the presence of which feature is in some way connected 

 with stamen sterility. The climax of these modifications in the group is the almost 

 complete perversion of the androecium. A basis of generic distinction for certain 

 organisms hitherto in doubt is further offered by the study of the floral development. 



Dr. H. S. Holden. — On the Structure of the Endodermis in Aletris farinosa. 



Aletris farinosa is a small liliaceous plant occurring in the United States of America. 

 The endodermis of the root passes through transient primary and secondary phases 

 and, in the tertiary condition, consists of extremely thick-walled cells. The available 

 evidence suggests that the suberin lamella developed in the secondary phase does 

 not present a completely impermeable barrier to the exchange of materials between 

 the endodermal cells and those of the stele and cortex respectively. 



