ROLE OF BATS IN RABIES 223 



fectious diseases were ruled out. Gross postmortem findings were essen- 

 tially negative; blood smears did illustrate occasional blood parasites — 

 A naplasma and Babesia. All cattle were remarkably free of gross para- 

 sitism. 



Of the family Desmodontidae, the single species Desmodus rotundus 

 murinus, Wagner (Figs. 1-3), was involved in the writer's experience in 

 Honduras. It is strictly hemophagous and colonial with no tail or tail 

 membrane. It lives in caves, buildings and hollow trees for the most part, 

 but may also seek shelter in thatched roofs or any other secluded and dark- 

 ened area. Its diet consists of one or two mammalian blood feedings 

 each night. The daytime retreat can easily be discovered by locating 

 large accumulations of bloody droppings under the roosting area. The 

 bat approaches its blood source after sundown, often coming down to 

 the ground, approaching its victim, climbing up the leg of the animal 

 spider fashion without detection, and attaching itself to the hair in a 

 sheltered area on the neck where it cannot be easily dislodged by move- 

 ment of either head or tail. With the upper chisel-like incisors it scoops 

 out skin, causing capillary bleeding, and laps blood, often until it is 

 too full to fly. It then drops to the ground and makes its way to a 

 nearby shelter to digest the meal. It may return before morning to 

 feed a second time on the same victim, often at the same wound site, 

 and may consume up to 30cc of blood in a single feeding. Its specialized 

 twenty teeth, including functionless premolars and molars, narrow its 

 diet to blood (Fig. 4). According to Pawan's observations in Trinidad, 

 the gestation period is probably approximately three months. The 

 female bears a single young, occasionally two, which matures in a 

 year or less. It is stated that the bat's saliva contains an anticoagulant 

 which permits free flow of capillary blood at the site of the inflicted 

 wound. Some observers have noted erratic daylight flight with fighting 

 between bats in mid air and have assumed that such bats, especially those 

 that aggressively attack animals, are rabid and are in the furious stage. 

 These phenomena were not seen in Honduras. The life span is unknown, 

 but Pawan (1936) succeeded in keeping a captive vampire bat alive for 

 five years. The vampire bat has been shown to be a transmitter of yellow 

 fever and Trypansoma cruzi — Chagas disease — in addition to rabies. 

 Investigators in Brazil, Venezuela and Trinidad have demonstrated that 

 the virus of rabies may appear in the vampire bat, artificially infected, 

 seven days after subcutaneous injection, and that the bat may remain 

 symptom free for long periods. In individual cases it was shown that a 

 symptom free bat was capable of transmitting viable virus for five and a 



