502 SUMMARY OF CUKKENT EESEARCHES RELATING TO 



activity. The initial dose recommended . is 60-90 c.cm. of an equal 

 mixture of the three sera. The serum may be given intravenously or 

 subcutaneously, the former method being especially recommended. If 

 there be time to demonstrate which organism plays the principal role in 

 infection, the dose of the serum corresponding to" the particular anaerobe 

 may be augmented with advantage. 



Ropy Bread.* — J. M. Beattie and F. C. Lewis have carried out a 

 series of observations as to the cause of the condition known as 

 " ropiness " in bread. The work was originated some years ago in the 

 University of Liverpool, under the direction of the late Sir Rubert 

 Boyce. The causal organism appears to be a member of the mesenterkus 

 group of organisms, and has been described by Vogel as Bacillus viscosus 

 2)anis. The bacillus is Gram-positive, spore-bearing, and aerobic. When 

 grown on agar the appearance of an early colony is characteristic. It 

 looks like a small drop of thick, transparent, colourless oil, and when 

 touched with a needle is shown to be extremely viscid. If an attempt 

 be made to remove the colony, it will be found that the growth follows 

 the needle and can be drawn upwards, if handled gently, until a strand, 

 one or two inches in length, reaches from the agar to the end of the 

 needle. It is therefore very difficult to detach a portion of the colony. 

 As the colony develops, the clear oil-like character disappears, and a 

 ground-glass opacity is assumed, giving rise later to a dry, wrinkled, 

 typical mesenteric appearance. But the viscosity of the growth is seldom 

 entirely lost, the fresh growing edges invariably showing this character- 

 istic. The organism is non-motile, and forms, in pepton water, a thick, 

 transparent mucilaginous film, very different from the " greyish-white 

 film, which is not broken up by shaking," of B. mesenterkus vulgatis. 

 If a " ropy " loaf of bread be cut or broken, small glistening masses may 

 be found. These are colonies of the " rope " organism, and the silken 

 strands which may be seen when portions of the bread are drawn gently 

 apart are, in fact, only the viscid colony stretching from crumb to crumb. 

 When the growth in the loaf is well advanced, then the whole mass may 

 become viscid. 



The causal organism, B. viscosus panis, is present naturally in the 

 husk of the grain, and the infection is more likely to occur where the 

 flour used contains a greater proportion of husk. There is no doubt 

 that the development of the organism in the bread is greatly favoured 

 by moisture and heat, conditions which would be established by storage, 

 after baking, without proper ventilation. The conditions should be 

 eliminated by using proper methods and standards in the production, 

 of flour. 



Morphological Studies in the Life-histories of Bacteria. f — E. C. 

 Hort endeavours to show in this communication that simple binary fission 

 is not the only method of reproduction amongst bacteria, and that only 

 a fraction of what appears to be a highly complex life-cycle can be studied 

 by cultivation in, or on, synthetic media. In his experiments organisms 



* Lancet, cxciii. (1917) pp. 211-2. 



t Proc. Eoyal Soc, Ixxxix. (1917) pp. 468-80 (5 pis,). 



