Cotton. — Notts on Wellington Physiography. 265 



Summary. 



The following conclusions have been reached : — 



(1.) The south-western extremity of the North Island of New Zealand 

 is probably a horst isolated by subsidence of land blocks on the west and 

 ■on the south, and possibly on the east also. 



(2.) The drainage-system has been developed by normal processes during 

 a long period of elevation punctuated by pauses, the amount of elevation 

 being at least 800 ft., and probably more. 



(3.) The nature of the longitudinal drainage suggests that adjustment 

 to structure was established in an earlier erosion period. 



(4.) A prominent feature, Port Nicholson, has been produced by the 

 subsidence of a block along lines which, with one notable exception, have 

 not been clearly recognized. 



(5.) This exception is the line of the Wellington fault, along which fault- 

 scarp topography is well developed. 



(6.) Eecent changes of drainage have had the effect of destroying, 

 rather than completing, previous adjustment to structure. 



(7.) This is attributable to the activity of transverse streams on and 

 near to fault-scarps. 



Art. XXVIII. — The Composition of some New Zealand Foodstuffs. 



By John Malcolm, M.D., Physiology Department, University of Otago. 



[Bead before the Otago Institute, 5th December, 1911.] 



I. Oysters from Stewart Island. 



Most of the oysters consumed in New Zealand come from the Bluff and 

 Stewart Island. Owing to their comparatively large size, their pleasant 

 flavour, and moderate price they form a much-prized addition to the 

 dietary of all classes. So far as the writer knows, no analyses of these 

 oysters have been published hitherto. 



The samples examined were procured from a fishmonger in the usual 

 way, and were then probably not more than three days out of the sea. 

 The analysis was begun forthwith, care being taken in opening the 

 oysters not to allow particles of the shell to mix with the contents. The 

 amount of sea-water and other fluid obtained on opening and draining 

 the oysters amounted to about 3 c.c. each, a quantity, however, which de- 

 pends on the time elapsing between opening and draining. As the animal 

 dies it undergoes rigor mortis, or some analogous change, with the result 

 that more fluid can be drained off; if heated even slightly the amount 

 is still more increased. In the samples analysed the opened oysters were 

 immediately drained under light pressure in a cheese-cloth, then minced, 

 dried, ground in a coffee-mill, and preserved in powder form. 



Method 



Glycogen was estimated in the fresh material by Pfliiger's method — 

 i.e., the weighed sample was heated with strong KOH on the boiling- 



