- 34 - 
pp. 21-22: It is not advisable to grqw buckwheat for use 
by bees alone. Commercial beekeeping in buciyheat-growing 
sections is advisable, as bees c^n make use of the flowers pro- 
duced and may in turn be of use in fertilizing the flowers . 
Many buckwheat growers, in fact, believe, that the weight per bushel 
of the seed is heavier where the crop* has 'been worked largely bv 
bees . 
White, J. W., Holben, F. J., and Richer, A. C. 
1941. Experiments with buckwheat. Fa. Agri, Expt. Sta. Bui. 403, 62 pp. 
p. 57: Buckwheat plants are a valuable, source of nectar, and 
since the common varieties are highly self-sterile, bees are of 
great value in bringing about cross-pollination. 
Cabbage 
Pearson, 0, H. 
1932. Breeding plants of the cabbage group. Calif. Agr. Expt. Sta. 
Bui. 532, 22 op. 
pp. 4-5: Insects visit the flower ( Brassica oleracea) freely. 
Honeybees, although usually plentiful, often fail to be very effi- 
cient, because they do not work at temperatures below 60° F. 
Bumble-bees are not very plentiful in California, but usually a 
few of them are collecting pollen in nearly every field. 
p. 7: Cross-pollination which is the rule in Brassica is 
usually brought about by insect visitation . Bees are the active 
pollinating agents . 
Carrots 
Robbins, W. W. 
1931. The botany of crop plants. Ed. 3, 608 pp. Philadelphia. 
p. 510: The flowers are mostly insect-pollinated. 
Umbelliferea (Carrot Family) 
(Carrot, Parsnip, Celery). 
Robbins, W. W. 
1931. The botany of crop plants. Ed. 3, 608 pp. Philadelphia. 
p. 504: The umbellifers are usually insect-pollinated. 
Protandry is common. 
