4 LETTER OF TRANSMITTAL. 
number of colonies of bees it now supports. This branch of agri- 
cultural industry does not impoverish the soil in the least, but, on the 
contrary, results in better seed and fruit crops. The total money gain 
to the country from the prosecution of this industry would undoubt- 
edly be placed at several times the amount given in the table above 
were we only able to estimate in dollars and cents the result of the 
work of bees in cross fertilizing the blossoms of fruit crops. In sup- 
port of this it is only necessary to refer to the fact that recent inves- 
tigations by another division of this Department have shown that 
certain varieties of pear are nearly or quite sterile unless bees bring 
pollen from other distinct varieties for their complete cross fertilization. 
I respectfully recommend the publication of this manual as No. 1 of 
the new series of bulletins of this division. 
respectfully, L. O. HOWARD, 
Entomologist. 
Hon. J. STERLING MORTON, 
Secretary of Agriculture. 
