76 BULLETIN 208, UNITED STATES NATIONAL MUSEUM 



dry comb given them and it was found that the consumption amounted 

 to 24.8 grams per bird per day. 



The bird that died after 29 days had its gizzard full of crumbled wax; 

 the other bird's gizzard was empty, but it had been feeding on wax up 

 through the previous day. The fact that it had been seen eating wax 

 the day before and yet had none in its gizzard suggests that wax is not 

 necessarily retained for some time in the alimentary tract, as might 

 have been supposed, to help accoimt for its almost invariable presence 

 there in wUd killed birds. (It had been thought that possibly the 

 birds did not have to get wax as frequently as they do if they were 

 able to hold it in the gizzard for a slow and prolonged digestive process.) 



Skead described the symptoms exhibited by the birds during their 

 last days in a letter to Osman-HUl, Prosector of the Zoological Society 

 of London, who replied that the symptoms sounded strongly suggestive 

 of peripheral neuritis or beri-beri caused by deprivation of vitamin Bi, 

 of which the throwing back of the head is a classic symptom. Other 

 elements of the B complex may also have been lacking, as it is rarely 

 the case that only one of the components is responsible. In a state of 

 nature the birds eat insects as well as wax, so this deficiency does not 

 obtain. 



While it is inconclusive to argue from analogy, it stUl seems worth 

 pointing out that the English sparrow, Passer domesticus, a bird about 

 the same size as, but whoUy unrelated to, the lesser honey-guide can 

 survive without food for only 67.5 hours at 29° C. With a rise in the 

 air temperature from 29° to 46° C. the survival time decreases at the 

 rate of four hours per degree (Kendeigh, 1945). If beeswax were 

 indigestible or without nutritive elements, as the literature suggests, 

 and therefore not to be considered as "food," it would be astonishing 

 indeed that the lesser honey-guide could survive without food ten or 

 more times as long as the sparrow. 



It may not be out of place to include here a piece of negative infor- 

 mation. During my studies of wax it occurred to me that this material, 

 then supposed to be indigestible, might serve the function of adsorbing 

 certain ions from the digestive fluids in much the same way that some 

 gums and resins are used in human medicine. The Eli LUly Research 

 Laboratories made the necessary tests for me on beeswax and found 

 it to have no such properties. Commercial white beeswax was ex- 

 posed to a solution containing sodium, potassium chloride, and phos- 

 phate in approximately the same concentration as occurs in the human 

 gastrointestinal tract. Thissolution was buffered at pH 6.7. A ratio 

 of 2 grams of beeswax to 100 cc. of this solution was used, and after an 

 exposure of one hour with constant agitation no detectable uptake of 

 either sodium or potassium had occurred. 



