256 BACTERIA. 



I consider that the interpretation he gives of the appearances 

 presented is perhaps the most satisfactory that has yet been 

 published. The tumour from an ox was fleshy in consistence, 

 had a faint pink colour, and was studded with minute softened 

 pink points, and in each of these points was found an 

 actinomyces colony, at the margin of which, however, only 

 a few of the characteristic clubs could be found, the centre 

 being finely granular. On making sections of these tumours, 

 that had been hardened in alcohol, and staining by Gram's 

 method (see Appendix), and examining under a high magnify- 

 ing power, Professor M'Fadyean observed that the colony 

 consisted of three distinct elements, though, in many 

 instances, the club-like bodies were absent. The first element 

 is a coccus about .5^ in diameter ; these cocci are usually 

 arranged in chains consisting of ten or fifteen elements, a few 

 of them are usually found in the centre of the mass, but 

 immediately outside this they are exceedingly numerous, so 

 numerous indeed that they appear to be more like masses 

 than chains ; as we approach the margin again the chains 

 radiate outwards and are very distinctly seen. Where they 

 are not very numerous, some larger cocci may be seen under- 

 going regular vegetative division, so giving rise to the forma- 

 tion of diplococci. 



The second element is a thread-like leptothrix or clado- 

 thrix, a number of which, interlacing freely, form a kind of 

 felted net-work, especially in the centre of the colony. As 

 we pass outwards, however, they gradually assume a more 

 regular radiate arrangement, and near the periphery " they 

 sometimes shoot out in a tendril-like manner beyond the 

 coccus heaps already described." These threads vary very 

 considerably in length ; sometimes they are divided into 

 short bacilli or even into cocci ; in other cases long threads 

 without any sign of division may be seen. The diameter of 

 these threads is usually greater than that of the cocci. They 

 are described " as some nearly straight, others gently curved, 

 and occasionally they show short nodules almost like a 

 spirillum." Near the margin these threads sometimes 

 become branched just as in the case of the club-like forms 

 already mentioned. The club-like forms when met with 

 here appear to bear a definite relation to the threads ; they 

 are only found at the margin of the fungus mass ; they are 

 arranged radiately with the ends of the clubs outermost ; 



