PURINE BASES 379 



With regard to the higher plants, De Vries considers that 

 alkaloids are not used in assimilative processes, since in the 

 germination of the seed of the potato, the thorn-apple {Datura 

 Stramonium) and nux vomica {Strychnos mix vomica), little 

 or no diminution in the substances in question occurs. 



Similarly Sabalitschka and Jungermann * find but a small 

 decrease in the lupinin content of Lupinus luteus and the 

 strychnine content of Strychnos nux vomica in the early 

 phases of germination ; in the former plant there is a loss of 

 about one-fifth and in the latter about one-fourth of the 

 total amount after two weeks germination. In the lupin, 

 this is followed by a rise which reaches a maximum at the 

 end of fourteen weeks from germination which is about the 

 period of seed setting. There is then a fall in the alkaloid 

 content in the vegetative organs and an increase in the seeds 

 which the authors think is not so much due to translocation 

 but rather to the formation de novo of lupinin in the seed. 

 In view of the small loss in the cotyledons during germination, 

 it is not considered that these alkaloids are a reserve food. 

 Annett f concludes that morphine is a useless end product of 

 the metabolism of the opium poppy, Papaver somniferum, 

 which is stored where its accumulation can do no harm to 

 the plant. 



These opinions are to a certain extent supported by the 

 fact that the presence of alkaloids depends, at any rate in some 

 cases, on the conditions of cultivation ; for instance, quinine 

 does not occur in cinchona cultivated in hot-houses in this 

 country. 



From the facts relating to the distribution of betaine in 

 plants, Stanek % concludes that this substance is not a nitrog- 

 enous reserve but is used up by the plant during its develop- 

 ment. 



Lotsy§ considers that alkaloids, such as quinine, are 

 not decomposition products of proteins, but direct synthetic 



* Sabalitschka and Jungermann : " Biochem. Zeit.," 1925, 163, 445 ; 



1926, 167, 479- 



t Annett : " Biochem. Journ.," 1920, 14, 618. 



t Stanek : " Zeitsch. Zuckerind.," 1913. 37» S^S- 



§ Lotsy : " Bull. Inst. Bot. Buitenzorg," No. 3, 1900. 



