Tl^AlSl SACTIONS 



OF THE 



NEW ZEALAND INSTITUTE 



Art. I. — On the Toxicity of Tutu Fruit and Seed.^ 



By Professor John Malcolm, M.D., Physiology Department, University 



of Otago. 



[Read before the Otago Institute, 10th September, 1918; received by Editors, 13th 

 September, 1918 ; issued separately, 14th Ulay, 1919.] 



Attention has frequently been drawn to the remarkable fact, discovered 

 by the Maoris, that the juice of the ripe tutu-berry is harmless, while 

 the seed is intensely toxic. 



It says much for the intelligence and powers of observation of that 

 race that such a discovery should have been made. Perhaps the pos- 

 session of subjects of experiment in the form of prisoners of war played 

 a part in establishing the fact. As the writer had already reported some 

 experiments on the toxicity of shoots a,nd leaves of Coriaria ruscifoUa 

 and C. angustissima, the opportunity was taken last summer of collect- 

 ing some of the fruit in order to test the degree of toxicity of the seed 

 of C. ruscifoUa, and at the same time to examine the juice. The 

 material was obtained by stripping the so-called " berries " off the 

 stalks of the racemes (sample I), and in another case (sample II) by 

 simply shaking twigs laden with fruit inside the calico collecting-bag. 

 In the latter case only the fully ripe berries dropped off. 



The juice was expressed by simple pressure on the bag, and the seed 

 vvas obtained from the remainder by washing and kneading the bag till 

 the strainings were almost colourless. By suspension in water it was 

 then comparatively easy to separate the seed from other debris, for the 

 latter renjained suspended for a longer time than the seed. A consider- 

 able proportion of the seeds rose at once to the top and floated there, 

 but the bulk of them sank rapidly to the bottom. The seed was dried 

 in the air, and thus preserved for future use. 



The Juice. 



A known quantity of the juice as first expressed from the bag was 

 evaporated down on a slow fire. The reaction remained acid during the 



* The expenses incurred in this research were defrayed out of a Government 

 grant made through the New Zealand Institute. 



1— Trans. 



