508 THE AMERICAN NATURALIST. [Vor. XXXIX. 
small homceopathic vials of alcohol, and several rat traps) and the 
ease with which material can be gathered from rats, dogs, cats, and 
human beings, should make possible the readv coóperation of all 
biologists and medical men and a hearty invitation is herewith ex- 
tended to all such and to any other persons interested. As large 
series of specimens as. possible should be taken and full data as to 
locality, host, etc., should be inserted in every vial. A direct report 
will be immediately returned for all specimens sent either to the 
writer or to Dr. L. O. Howard, Government Entomologist, in Wash- 
ington, U. S. A., and full published credit will later be given for 
every sending. 
It will greatly facilitate the rapid progress of the work if entomo- 
logical, zoólogical, medical, and pharmaceutical journals the world 
over will kindly copy this notice. 
C. F. BAKER. 
ESTACION AGRONOMICA, 
SANTIAGO DE LAS VEGAS, CUBA. 
(Vo. 462 was issued June r 3, 1905.) 
