138 CLASSIFICATION OF THE MICRO-ORGANISMS. 



Development animals in large numbers without causing any bad effects. 



by cultivation According to Grawitz, however, malignancy can be produced 

 of malignant t , , ,. . . . . , ? , J . .,-, 



properties in ^J g ra dual acclimatisation ot the mould fungi on nuid alkaline 



mould fungi, substrata, and at the temperature of the animal body. This 

 view rests on an error, for Grawitz evidently worked with a 

 mixture of spores of Asp. flavescens and penicillium : when he 

 cultivr.t3d this mixture at a low temperature (15 C.) only the 

 penicillium, which was quite harmless, grew; when, however, he 

 employed temperatures of 35 37 C., the luxuriantly grow- 

 ing aspergillus overpowered the penicillium, which grows only 

 imperfectly at this temperature, and the aspergillus cultiva- 

 tion, which was quite similar in appearance to the penicillium 

 cultivation grown in the cold, furnished spores of a malig- 

 nant nature. 



Addendum: Actinomyces, Ray Fungus. 



A peculiar parasite, the relationship of which was 

 till recently quite doubtful, may find a place here 

 provisionally ; I refer to the so-called ray fungus. The 

 disease set up by this fungus is most frequently observed 

 Morphological in the jaws of cattle. It forms there a whitish tumour, 

 theray ' which springs from the alveoli of the molar teeth, or 

 from the spongy tissue of the bone, expands the latter, 

 erodes it, and finally bursts outwards, or in rare cases 

 inwards. The substance of this new formation, which 

 is in the main soft and juicy, shows on section a large 

 number of yellowish, abscess-like foci, from which 

 peculiar bodies are obtained on scraping, about the size 

 of a hemp seed, of a sulphur yellow colour, and with a 

 fatty feel. Similar deposits are found in the pharynx, 

 in the larynx, in the corresponding lymphatic glands, 

 &c. On closer examination these yellow bodies are 

 found to present a coarsely granular, often mulberry-like 

 appearance, and consist of numerous closely interwoven 

 threads. On slight pressure the round gland-like 

 bodies break up into a number of fungus masses ; these 

 are groups of bifurcated threads, like hyphse, which, 

 gradually spreading out from the centre, end in club or 

 flask-like swellings (Bellinger). The threads are usually 

 straight, more seldom slightly wavy, or even spiral, and 

 they swell more and more towards the periphery. As 



