590 Transactions of the Society. 



All attempts at propagating bacilli in honey I have found utterly 

 futile. The presence of bacilli in honey as an accidental con- 

 tamination would, it may be remarked, in no way render it in- 

 jurious, for many pathogenic bacteria may be swallowed without 

 risk if there be no internal rupture of the mucous membrane, and 

 placing this bacillus in a skin wound has in my own case produced 

 no disagreeable results. 



My belief is that the grubs are most usually infected by the 

 antennae of the nurses. These travelling in the darkness of the 

 hive become aware of the condition and needs of the occupants of 

 the brood-cells by constantly inserting their antennae, which must 

 continually where disease reigns be brought into contact with 

 bacilli, and also into contact with those sticky masses into which 

 the larvse change about two days after death. The removal then of 

 spores is highly probable, and these transferred to the next grub 

 fed will there start the disease. These sticky masses will be found 

 too to extend to the very front of the cells, and as the bees 

 perambulate their combs the pulvillus will be in danger of re- 

 moving spores and depositing them upon other cell edges to infect 

 other grubs at the critical time of cocoon spinning. It is also 

 extremely likely that the tramp of the bees frequently detaches 

 numbers of spores, which fly about in the air and settle here and 

 there, often where they take effect, many of them being carried 

 into healthy stocks with the indraught set up by the fanners.* 



A large number of observations has shown that the disease in 

 the larva at least is not one of the digestive tube, but of the blood, 

 and through it of every viscus. If honey were the means of com- 

 municating it, certainly traces of it should be found in the alimentary 

 sac ; but here I find only very occasionally bacilli. In the adult 

 bee, however, although the disease fills the blood, it is still very 

 prominent indeed in the chyle stomach. Microscopists will have 

 no difficulty in accepting the idea of these organisms being carried 

 about in air currents when it is remembered that a single cubic 

 inch of material would form a quadruple line of these bacilli from 

 London to New York. Ordinary dust motes are to such organisms 

 as hens' eggs to sand grains. Nor is their multitude less remarkable 

 than their minuteness. I have examined many larvse which must 

 at least have contained 1,000,000,000 ; so that the means by which 

 they are disseminated must be altogether too varied. In the royal 

 jelly— so called— of a queen pupa dead of bacillus I could discover 

 no bacilli, nor have I succeeded better with the food provided to 

 the workers, notwithstanding that I examined several hundreds of 

 the cells containing feeding larvae where disease was rife ; so that, 

 although I would not dogmatize, my strong opinion is that commonly 

 neither honey nor pollen carry the disease, but that the feet and 



* See svpra, p. 583, line 13 et seq. 



