24 
14th May.—Tree No. 15--At 8-30 a.m. 64 flowers found open ; 
within 45 minutes, 52 of these were visited by insects. 
14th May.—Tree No. 18-b—At 10-30 a.m. 88 flowers found 
open; within 15 minutes, 24 of them were visited by insects. 
“The visiting insects were, in each case, examined and were 
found invariably to be covered witb pollen. 
‘The paper under reference also contains an account of observa- 
tions on the robusta varieties of coffee, where it was found that self- 
fertilization in the bud rarely takes place. ‘Ihe author found here also 
that foreign pollen grains grow more rapidly down through the tissues 
of the style than do the ‘self’ grains. 
‘‘ With regard to Liberia coffee, the author concludes that cross- 
fertilization was the original method and tbat self-fertilization has 
arisen later to guard against failure in fertilization. 
“ Ag far as I am aware, no similar studies have been made on 
coffea arabica either in India or elsewhere and it would, I believe, be a 
matter of considerable practical interest to ascertain whether a 
difference in the rate of growth of foreign and ‘self’ pollen grains 
exists here similar to that described by von Faber for Liberia coffee 
in Java.” 
15. Dr. von Faber’s experiments show that the plant itself 
expresses a decided preference—if such a phrase is admissible—for 
foreign pollen; or, in other words, cross-fertilization is secured when- 
ever possible, self-fertilization being kept in reserve as a last resource. 
The experiments in the Shevaroys and Babadudins show that there is 
little difference in the quantity of flowers fertilized by insect-visitors 
and Dr. von Faber’s paper explains (no doubt correctly) why this is so, 
but this does not necessarily mean that there is no difference in 
quality between berries from flowers which have been cross-fertilized 
and from those which have been “‘selfed”. The quantity of beans 
collected from the experiments is too small to ensure a satisfactory 
comparison of quality, but the endeavour made by the plant itself to 
secure cross-fertilization strongly endorses the idea that such cross- 
fertilization is highly desirable—a view which is of course in accord- 
ance with experience gained in the case of other plants. We may 
conclude, therefore, that the visits of pollinating insects should be 
encouraged as far as possible. 
16. Turning now to the insects which secure such cross-fertiliza- 
tion in coffee, before carrying out the experiments, I endeavoured to 
find out what information was available regarding such insect-visiters 
of coffee in India, but the information available proved to be most 
remarkably scanty. Knuth’s ‘‘ Handbook of Flower Pollination”. to 
which one naturally turns for information on sucha subject, gave very 
little information on this point, as is shown by the following extract 
(English translation, Volume IL, page 549) :— 
“ Coffea arabica, L.—According to Bernoulli (Bot. Ztg., Leipzig, 
XXVIII, 1869, page 17) only small purely female fertile flowers are 
present at the beginning of anthesis, Ernst states that the herma- 
phrodite flowers are protandrous. 
“ Visitors—Bourdillon chiefly observed Lepidoptera (Nat: 
London, XXXVI, 1887).” picopters. (Natare, 
