193 



tion might be clue. The result of Mr. Auchinleck's investigations 

 have been presented by him in the form of a report from which the 

 following information is taken. They show that experience in 

 Grenada is confirmatory of that which has been described already 

 from other parts of the world. 



Mr. Auchinleck points out that the low germinating power of 

 imported seed is obviously due to actual sterility of the seeds to their 

 rapid deterioration after maturit3% or to both causes acting at once. 

 For the purpose of obtaining information in regard to the suggested 

 deterioration, seeds from capsules which had been opened just before 

 dehiscence took place were planted tw^enty-four hours after the fruits 

 had been plucked, a few^ being kept, however, for three days. The 

 number of seeds collected altogether was 975, and 160 of these were 

 set aside as being too light. That there is a great difference in weight 

 between the heavy and light seeds is shown by the fact that lOO of 

 the former were found to weigh 16 oz ; while the weight of the same 

 number of light seeds was only 6 ozs ; there was, however, no 

 observable difference in size between the two kinds. 



In the continuation of the experiment, all the light seeds were 

 planted in a bed, while of the heavy, eighty were sown at stake and 

 seventy-five in pots. None of the light seeds" germinated ; of the 

 heavy, nineteen of those at stake, and thirteen in pots, gave sproutS' 

 These results appear to justify the rejection of light seeds when those 

 of Hevea are being selected for planting. 



Observations on the rapidity with which the seeds lose weight 

 together w-ith the consideration that from two weeks to several months 

 are required for germination, led to the supposition that the rate at 

 which heavy seeds become lighter in the soil might result in a serious 

 diminution of their power to germinate, before the young plant has 

 had time to pierce the hard seed coat. This led to the following 

 experiment, undertaken to find how quickly heavy Hevea seeds may 

 lose weight. 



For the purpose, ten heavy seeds were packed in thoroughly 

 dried charcoal, in a flask; w^hile ten others were placed in a flask 

 open to the air. Each lot was taken periodically from its flask, at the 

 same time, and weighed, with the following results: — 



Day of Weighing. Sekds in Air. Seeds in Charcoal. 



Grams. Grams. 



1st. 48.8 49.0 



5th 48.5 43.5 



9th 47.0 40.5 



15th 45-5 38.7 



20th 44.4 38.0 



25th 43.0 37.5 



30th 41.8 37.2 



42nd 39.0 37.0 



49th 38.0 37.0 



54^^11 37-5 37-0 



