379 



s 



Capt. (now Commandant) Vacher, who was in charge of the 



Tsivory District (sectenr) of Southern Madagascar frc_ 



1907. ~ 



The two species have now been identified by Jumelle, from 

 specimens collected by Sergeant Mauriere, at the instigation of 

 Commandant Vacher ; " Vahy vanda n as Plectaneia elastica, Jum. 

 et Perr., and * Kidroa ,1 as H Mascarenlxasia Usianthijlora, DC. 

 Neither species appears to be of much economic importance, and 

 their chief interest is rather geographical and ecologic. At the 

 most favorable estimate a native would take seven or eight days 

 to collect a kilogramme of the rubber during the good season, 

 April-June, and twice that time during October-November. 



Plectaneia elastica was previously known only from the forest 

 of Analamahitso, Haut-Bemarivo, North- West Madagascar, and it 

 is somewhat surprising to find it in the extreme south of the 

 island. In the Fort-Dauphin Division, according to Capt. Vacher, 

 P. elastica grows into a bush 2^-5 ft. high, if there are no trees on 

 which it can climb ; as a climber, however, it reaches the tops of 

 the highest trees, but the stem nevertheless remains slender, 

 hardly exceeding 1\ in. in diameter. In North- West Madagascar, 

 on the other hand, Perrier de la Bathie saw stems measuring as 

 much as 8 in. in diameter at the base. The same relation holds 

 good for Mascarenhasia lisianthiflom, which in the south is a 

 shrub 6-12 ft. high, with a stem about I £ inch in diameter, whilst 

 in the north-west it may become a tree 20 ft. high, with a trunk 

 8 in. in diameter. As a general rule, according to Jumelle, the 

 species of North-West Madagascar become dwarfed as they 

 approach the south of the island or the central plateau, and this 

 relation extends even to representative species : thus Cryptostegia 

 grandiflora of Southern Madagascar is a smaller plant and yields 

 jess rubber than C. madagascariemis, the corresponding species 

 in the north-west. 



'sianthifl 

 2600 ft." ( 



tica md Ma 



the 



ca 



M, 



T. A. S. 



Experiments with Rubber Seeds-Experiments have been carried 



ont by Mr. H. F. Macmillan, Curator, and Mr. T. Petch, Govern- 

 ment Mycologist, Peradeniya, as to the weight and germinative 

 capacity of Hevea rubber seed. 

 The seed was collected from (A) a group of trees about 20 years 



^iy ruDDer Deing taken from eigni u-ee» *« »****~ — - /» 



aionally in 1906, but not at all in 1907. One thousand seeds were 

 taken from each group, and each 1,000 were divided into 10 lots 

 of 100 each, which were weighed separately. One lot from each 

 group was planted on September 14th, and the remaining lote i were 

 Planted in pairs, after weighing at intervals of a week unti I all 

 were planted. It was found that the seeds lose weigh t rapid y 

 during the first fortnight after collection, and then more gradually 



