EUROPEAN FOULBROOD. 27 



Through the study of microtome sections of such larva', it lias been 

 conclusively proved that infection takes place in this way. The fact 

 is naturally one of special moment in the solution of the transmission 

 of the disease. There is a tendency on the part of adult bees to 

 remove sick and dead larva? from the brood comb. This is done 

 largely at least in a piecemeal manner. Were the fate of the frag- 

 ments removed known definitely the solution of the problem natu- 

 rally would be aided greatly. 



If infective material thus removed were fed to susceptible 

 healthy larvae, disease would result. On the other hand should the 

 fragments of diseased larv£e be stored with the honey of the hive 

 or with the pollen, or consumed by the adult bees, or by larvae 

 later in the feeding stage, the chances that such material would 

 ever reach susceptible larvae to cause infection are very much re- 

 duced. Stored in honey the virus remains virulent only a few 

 months (p. 24) ; in pollen, however, it remains virulent much longer 

 (p. 24). Drying within the hive BadUus plwton would probably 

 remain alive more than a year (p. 19). 



The chances that any portion of the infectious material of any 

 given fragment, if it is removed entirely from the hive by the bees 

 of the colony, and released from them, will be taken up by other 

 bees and carried to healthy brood and cause infection are compara- 

 tively slight. If thus removed and exposed to the direct rays of 

 the sun, the virus will be destroyed within a few hours (p. 19) ; 

 or if subjected to fermentative or putrefactive processes it will be 

 destroyed in a few weeks (p. 23). If Bacillus pluton is present in 

 honey extracted from diseased colonies it will be destroyed within 

 a few months while in storage (p. 24). It is seen, therefore, that in 

 nature there are many means that destroy the virus of European 

 foulbrood and thus limit the spread of the disease. 



All of the colonies of the experimental apiary used in making the 

 inoculations cited in the present paper had free access to the fields 

 and there was no evidence at any time of the transmission of the 

 disease from infected to healthy colonies. This fact supports the 

 conclusion that the disease is not spread by way of flowers visited 

 by bees from healthy colonies which had been visited previously by 

 bees from diseased ones. The fact further indicates that if the dis- 

 ease is transmitted at all by way of the water supply of the bees, it 

 takes place to a limited extent only. The fact still further indicates 

 that if drones or straying or drifting workers transmit European 

 foulbrood they do so to a slight extent only. If these observations 

 are at variance with the experience of the practical beekeepers, 

 as the writer has been informed that they are, they will probably be 

 of particular interest. 



