Bacillus alvei. By Messrs. F. Cheshire & Watson Cheyne. 585 



small ovoid bodies, as I have shown at fig. 1. These are the 

 micrococci of Schonfeld ; but if this substance be stained according 

 to the plan of Weigert and Koch, and then carefully examined even 

 with a good 1/4, we shall in all probability discover a very few un- 

 doubted bacilH, fig. 1 h. Whilst operating thus, the absence of dumb- 

 bell forms and the distinctly oval shape of what I presently found 

 to be spores of the associated bacilli, arrested at once my atten- 

 tion. Now possessing myself of an infected stock, so that the 

 course of the disease could be traced, I submitted first the body of 

 a grub dead, but in a fresher state, to the Microscope ; and here 

 the bacilli were numerous, although still few in relation to the 

 number of the spores. Then selecting larvae still feeding, but of 

 suspicious colour, and examining their juices with a power of 600, 

 I was delighted by seeing hundreds of bacilli actively swimming 

 backwards and forwards and worming their way amongst the blood- 

 cells and fat-globules, as presented at fig. 3, whilst the leptothrix 

 form was not uncommon. 



The examination of a larger number of larvae, not only from 

 the stock referred to, but from combs coming from various parts of 

 Great Britain and Ireland, showed most conclusively that each in- 

 dividual at the beginning of the attack contained many bacilli of 

 an average diameter of ■ 5 /i, and length 4 /x, mostly swimming with 

 a corkscrew-like movement, and that if an end view were obtained 

 of any one of them the termination of the rod constantly described 

 a small circle ; that when the disease was in rapid progress, lepto- 

 thrix forms were common, some of these even reaching 250 yu, in 

 total length ; that as the fluids of the grub failed by loss of fats 

 and albumenoids, the bacilli began to swell centrally, drawing 

 the mycoprotein from their extremities, as seen in fig. 8, and 

 thus gradually becoming spores, fig. 8 ; that after the death of 

 the grub and dimng the assumption of the viscid, putrid condition, 

 this constant alteration of bacilli into spores continues ; that after 

 removal from the hive it goes on so rapidly that in a day or two 

 scarcely a bacillus as such is discoverable, whilst the spores are 

 innumerable, and, in addition, that a very cautious preparation of 

 some broken down viscus showed that the bacilli and spores arranged 

 them.selves in that most singular line fashion (fig. 10) which 

 Mr. Watson Cheyne found subsequently to be characteristic in his 

 agar-agar jelly cultivations of the same micro-organism. 



Since the force of conviction obliged me to deny the accuracy 

 of Schonfeld's conclusions, I felt it incumbent upon me to repeat 

 his experiments, for if the disease be really duo to a bacillus, how 

 could the communication of it to Musca vomitoria produce, as he 

 says, micrococci in that insect? I experimented on sixty indi- 

 viduals : twenty were not brought near foul-broody matter, twenty 

 1 attempted to infect with bacilli in their active condition, and 



