Co«53:^di»g General Leonard D. Keaton 
Walter Reed Arisy Medical Center 
Maaaington, D. C* 
Dear General Heaton: 
Tfeia Institytlon ia sponaorliig the SBlthaoniaii-Bredin 
Belgian Congo Expedition for the purpoae of siwi^ing tije inverte- 
brate life of that area, ijartieularly aites, tleks, and fleas, 
tJieir plant and antoal hosts, terrestrial and fresh water 
Crostacea, nollusks and fish* Dr. Waldo L. Sclmitt, head curator 
of aoology in the United States iational Museum iiill be in charge 
of trei field work and will p^r^nally be concerned with the 
aquatic invertebrates. The eetoparasltas will be looked after by 
Ur. Edi^rd Baker, acarologist of the United States F^tepaurteent of 
Agriculture. 
Ab we also wisFi to keep a photo-record of the e>q)editlon*s 
operations ai^ of the animals collected and studied in the field, 
we have urgent need of an caqperienced scientific photographer. 
Many of anirials and parasites in Wbieh we are especially 
interested are of small, often microscopic, siae,and very diffi- 
cult subjects to photograph in life and in their natu^tl habitats. 
Your F^r. toy L, Sexton, dr, chief of tee photo-iaboratoary 
at th© Array Medical Center, is known to us for Ms unusual com- 
petence in f-edical and alcro-pbotography. For tliese reesons we 
write you in the hop# tiiat you and your Service may be able to 
cooperate with the Sraithswsian to the extent of granting Mr, 
Sexton official leave of absence for the purpose of participating 
in the expedition as staff photographer. He would be expected 
to report in Leopoldville, where tei® e;iq}edit ionary i^ty will 
ass«rjble, on April 11 and should be able to return to l^shington 
via Cairo, Fgypt by June 22. His ®Xf>ense3, travel and subsistence 
for the duration of his stay in Africa, »K>uld be borne ly this 
Institution, wiiieh lasuld also supply all necessary ptotographic 
supplies. 
