312 Tra7isacfio7is. 



12. Any diameter of the circle ABC will invert into a 

 rectangular hyperbola. 



Let the diameter be taken which is perpendicular to the 

 line a= ; the equation of its inverse is 



sin (B — C) sin B sin C 

 a fi y 



This conic cuts the circle ABC at the extremity H of the 

 diameter which passes through the vertex A of the triangle of 



reference; it also passes through the points | _ - - -j and 



the orthocentre of the triangle ABC : its centre is at the 

 middle point of the line BC : the tangent to the conic at A 

 passes through the symmedian point (abc) of the A ABC, 

 while the tangent at H passes through the point { — abc). 



Art. XXX. — Some Observations on the Coastal Vegetation of 

 the South Island of New Zealand. — Part I : General Remarks 

 on the Coastal Plant Coverincj. 



By L. Cockayne, Ph.D. 



[Bead before the Philosophical Institute of Canterbury, Sth August, 1906.] 



Contents. 



1. Introduction. 



2. Physiography and climate. 



3. Ecological factors. 



4. Dunes, salt marshes, and salt meadows. 



5. Physiognomy of the coastal vegetation. 



6. The small coastal islands ; endemisni. 



7. Southern and northern limits of coastal plants. 



8. Local and limited distribution. 



9. Primitive and modified formations. 



10. Mountain plants on the coast. 



11. Occurrence of coastal plants inland. 



12. Flowers of coastal plants. 



13. Coastal distribution as an aid in defining the floral districts. 



14. Floristic details. 



15. Life forms and adaptations of the true coastal plants. 



16. Details as to the inland- coastal plants. 



17. Introduced plants of the coast. 



18. Origin of the coastal vegetation. 



19. Some differences between the North and South Island coastal vegeta- 



tion. 



20. List of coastal plants proper, their distribution within and without 



New Zealand, stations and life-forms. 



21. Bibliography. 



