275 
EXPERIMENTS WITH RUBBER SEEDS. 
The Effect of Tapping on Seeds. 
Seeds from Tapped Trees Better Gerntinators. 
A circular has been issued by Mr. H. F. Macmillan, the Peradeniy* 
Curator and Mr. T. Petch, Government Mycologist, giving the results 
of events carried out as to the weight and germ.native capacity 
In order to obtain some reliable data as to the weight of Here 
seed its loss of weight and germinative capacity on keeping, anti how 
far the latter might be deduced from the separation of the cotyledons, 
a series of germination tests was instituted The seed at Peiaden y. 
tvas collected from (A) a group of trees, about twenty years old which 
have never been tapped, and (B> a group of trees about thirty 
years old, which were tapped regularly m 1905 (when -J lb-, ol y 
rubber were taken from eight trees in three months), occasionally m 
1906, and not at all in 1907. Presumably A are the descendants of 
B; if not, both groups are descended from the Henaratgoda .tie. 
1,000 seeds were collected from each group. Each thousand was ^divid- 
ed into ten lots of 100, which were weighed separately. One lot 
from each thousand was planted on September 14th ; on September 
21st the remaining eighteen lots were re-weighed, and one moie from 
each thousand was planted ; and the process was repeated each week 
until all were planted. Planting the seed is a departure from the usual 
method of testing germination, but it was adopted m this case ln f ^ 
to avoid the attacks of fungi, insects rats squirrels &c As far as 
possible, the treatment, i.e., depth and kind of soil, amount of water, 
&c., was the same for all. . . inn 
- The tables give the weights fin grams) of 100 e&fa on the 
date of collection and at each subsequent re- weighing. ’ 
lot 4 consists of 100 seeds, weighing 394 grams when collected on 
September 16th; left in open dishes in the laboratory, they dried to 
3,695 grams on September 21st, 341 grams on September 28th, and 
3 325 grams on October 5th, they were planted in October 5th. It 
was found that when they were kept in tall glass cylinders they turned 
mouldly in a few days. Lots 3 to 7 were collected and weighed on 
September 16th, and lots 8 to 10 on September 18th. It was impossi- 
ble to gather 1,000 seeds from these eight trees on the same day. Lot 
10 was sacrificed for another object after six weeks’ drying, as it was 
obvious that nothing would result from a germination test. It will be 
seen that the seeds lose weight rapidly during the first fortnight, and 
then more gradually till about the sixth week. After six weeks their 
weight is approximately constant at Peradeniy a, but, as will be seen later, 
further drying occurs if they are transferred to a drier atmosphere. 
The loss of weight in lot 7 after about six weeks’ exposure is 16.6 per 
cent.; in lot 8, 18.8 per cent.; in lot 9, 18.6 per cent.; and in lot 10 16.o 
per cent ; or an average loss of 17.6 per cent. This loss is practically 
all water, which condenses on the sides when the seeds are kept in 
glass cylinders. 
