RECOGNITION OF MICRO-ORGANISMS. 29 



In place of either of the above, there may be, as already pointed 

 out, large masses of micrococci, each of these masses embedded in a 

 glue-like matrix — gliacocci. In the case of bacteria there is similar 

 evidence of multiplication in the formation of pairs, where the two 

 elements are often arranged so as to contain a more or less obtuse 

 angle, or in the formation of regular chains — streptobacteria. Most 

 of these points were early recognised, and were described by Hiller, 

 Naegeli, and others. If once it is recognised that the granules grow 

 as above, then they must be organic. There is additional proof 

 of this, as von Recklinghausen, Klebs, Waldeyer, and FYiedlaender 

 pointed out, in the fact that in certain cases these micro-organisms 

 continue to multiply, even after death, in the blood-vessels, as is 

 evidenced by the fact that in cases of metastatic pyaemia, ulcerative 

 endocarditis, and similar conditions, small varicose swellings occur 

 at intervals along the course of some of the capillaries and small 

 veins. These dilatations are filled with masses of small round 

 granules which fulfil all the above conditions, and which, by their 

 rapid growth in si/ie, have caused the distention ; for only organisms 

 which have this power of multiplication could have brought about such 

 a condition. The same holds good for the distended lymphatics of 

 croupous pneumonia, in which Friedlaender demonstrated the presence 

 of the multiplying micrococci peculiar apparently to that disease. 



All bodies which do not conform to the above requirements may 

 be treated as either amorphous or granular precipitates, small particles 

 of inorganic material, or organic molecular granules. Inorganic 

 particles, angular or irregular in form, are also very irregular in their 

 size and mode of arrangement. They are far less refractive than 

 either micrococci or granules of organic matter, whilst by their 

 chemical reaction they are at once recognised. As an example of 

 these inorganic particles may be taken the oxide of iron, which is 

 frequently found in sections stained for tubercle, and then treated 

 with nitric acid. Here the acid acts upon the steel of the needle 

 usually employed, and an oxide is formed, small particles of which 

 are deposited on the section. These are readily enough recognised 

 by one who has worked even a short time at micro-organisms, but 

 they will serve as an example of the case in point. (In all cases 

 where acids are used employ platinum needles.) Organic molecular 



