130 
IOWA ACADEMY OF SCIENCE 
cause of an excess of water in the tissues. He considers nectar 
secretion analogous to the excretion of water through water 
stomata of leaves, the only difference being the presence of 
sugar in the underlying tissues in the former case and their 
absence in the latter. 
F. L. Sladen, Entomologist for the Canadian government, 
recently wrote a paper on nectar production. He cites many 
observations, but makes few generalizations. Great differences 
are noted in the behavior of different plants: heather yields 
well at low temperatures, the banner yield from it in England 
being on a frosty morning in September; white clover requires 
for nectar much moisture and moderate heat; sweet clover jter- 
mits while alfalfa requires dry air and considerable heat. He 
also finds differences due to character of the soil and subsoil, 
drainage, part of the blooming period and treatment of the crop. 
One of our most interesting problems is, I think, that of al- 
falfa, which is one of the standbys for honey in the Rocky Moun- 
tain states, but wliich is scarcely visited by bees in the Missis- 
sippi Valley states. It would seem that the warm moist weather 
conditions which beekeepers desire would be more certainly ful- 
filled in Iowa than in Colorado. Might the difference be due 
to the altitude of the western fields, and to the greater daily 
range in temperature that is given them, as Bonnier suggests ? 
The botany department of the State Experiment Station is 
beginning work on some of the problems of nectar production. 
We intend this merely as a brief preliminary report, rather 
with a view toward receiving suggestions than toward giving 
information. For we have as yet no important results to give. 
One part of the work the past summer has been the collection 
of the insect visitors of many sorts of flowers. Very striking 
is the preference exhibited by certain kinds of wild bees for 
certain flowers. For example, this spring a little solitary bee 
which swarms over the plum blossoms hardly notices the apple. 
We hope to ascertain the distribution of honey bees over flow- 
ers in such a way as to give the beekeepers a clearer idea con- 
cerning what kinds of forage, fruit and ornamental plants to 
grow in order to secure a large honey production. Sweet clover 
seemed a great favorite of the bees last summer, even in the 
driest weather. White clover yielded very poorly, perhaps be- 
cause it was weakened by the drought of the previous summer. 
