209 



The plant cultivated here is easy of cultivation from cuttings or 

 seed, but it has never established itself, though cultivated commonly 

 for upwards of 30 years or probably more, and it has by no means 

 the rapid growth attributed to it in Mexico. 



It is a shrubby climber readily forming a thick bush, and appar" 

 ently requires to be treated by a special process something like that 

 employed for Guayule. The plant is too small to tap, but the pro- 

 posal is to crush out the latex. In crushing, however, the green juice 

 of the plant combines with the latex and the rubber fails to coagulate. 

 However, this difficulty has apparently been overcome, as good rubber 

 has been obtained from it. There seems to be little doubt that the 

 plant was originally a native of Madagascar but perhaps of India 

 also. Mr. DoUey, however, is in error in stating that " In India it is 

 called Palay, a Malayan word and I believe written incorrectly Pulay 

 or Palai." Palay is not a Malay word, and there is no name for 

 the plant in Malay as it is only known of recent years in the Malay 

 region. 



It is hardly likely that the plant would ever come into cultiva- 

 tion as a source of rubber in this part of the world, but if it has run 

 wild to the extent described by Mr. DoUey, in Mexico, it might cer- 

 tainly be worth while working up there. — Ed. 



LONGEVITY OF SEEDS. 



An important contribution to our knowledge of the longevity of 

 seeds and, the structure of the seed-coat is published by Miss Bertha 

 Reesin the proceedings of the Royal Society of Victoria 23, II, p. 393. 

 In an earlier paper Professor Ewart divided seeds into three classes. 



Microhiotic seeds which do not live for more than 3 years. 



Mesobiotic seeds which last from 3 to 1 5 years. 



Macrobiotic seeds which may be able to germinate from 15 to 100 

 years. 



All the hard seeds are included in the last class. These seeds do 

 not swell when soaked in water. They are more abundant in a dry 

 climate than a wet one and seeds of the same species may vary in 

 hardness according to the climate in which they are grown. Plants 

 with hard seeds are most abundant among the Legnminosae, but occur 

 in other orders. The hardness of the seed is due in most cases to the 

 presence of an outer membrane or cuticle, but in Canna seed the ends 

 of the outer layer of long cells (palisade cells) are hardened and 

 there is no true cuticle. This cuticle is believed to be formed by the 

 deposition of particles of wax or fat in the cell walls. This prevents 

 the introduction of water. 



In order to let the water into the seed and so start the germina- 

 tion, several methods can be used. The most practical way is to 



