1886.] 



MICROSCOPICAL JOURNAL. 



205 



gelatin, spread out in thin layers on 

 glass plates, colonies are formed which 

 become visible to the naked eye after 

 48 hours as spherical or sub-spheri- 

 cal, homogeneous masses, bound- 

 ed (optically) by a smooth, regular 

 outline. The gelatin is )iot liquefied. 

 In tubes of gelatin each bacterium 

 multiplies into a round colony abovxt 

 \ the size of a pin's head ; when nu- 

 merous, a continuous whitish line or 

 band appears in the needle track 

 capped by a very slight surface growth. 

 On potato it forms a continuous patch 

 of a dirty straw color, from i to i mm. 

 thick. The bacterium does not pro- 

 duce spores, so far as we have been 

 able to learn. Cultures of all ages 

 are killed by an exposure for from 15 

 to 20 minutes to a temperature of 

 58° C. Micro-organisms containing 

 spores do not succumb thus easily. 



This microbe may, therefore, be 

 readily distinguished from others if 

 we take into consideration its micro- 

 scopic appearance, its motility in 

 liquid media, and the absence of 

 liqitefaction during its multiplication 

 in gelatin. 



Besides these important distinctive 

 characters, its pathogenic effect on the 

 lower animals is not less characteristic. 



In mice the disease is best marked 

 and the lesions most pronounced when 

 very small quantities of culture liquid 

 are introduced beneath the skin. Death 

 then occurs in from 8 to 14 days, and 

 quite suddenly. The bacteria are 

 easily demonstrated in all the internal 

 organs. The spleen is enormously 

 enlarged, and throughout the liver, in 

 most cases, patches of coagulation- 

 necrosis are found. If larger doses 

 are injected, the animals die within 4 

 or 5 days, and the above lesions are 

 not yet developed. 



In rabbits the introduction beneath 

 the skin of small quantities of culture 

 liquid is invariably fatal in from 4 to 

 5 days. Locally, the muscles are slight- 

 ly necrosed and the lymphatics en- 

 larged. The spleen is very much in- 

 creased in size. The bacteria are 

 found in all the internal orgfans. In 



guinea-pigs the pathogenic effect is 

 similar to that of rabbits, although the 

 fmniier seem somewhat more refrac- 

 tory. 



In pigeons a large dose is required 

 to produce death. They may die in 

 34 hours, probably from the effects of 

 the particular ptomaine formed by the 

 growth of the bacterium in the iDody 

 generally, or they may live from 3 to 

 13 days. In such cases a large se- 

 questiaun forms at the place of inoc- 

 ulation, and occasionally there are 

 microscopic changes in the internal 

 organs. Usually the bacterium is 

 present in the liver, sometimes in the 

 spleen. This bacterium has no effect 

 on fowls. 



These meagre statements concern- 

 ing its pathogenic effects are sufficient 

 to distinguish it from all other known 

 pathogenic bacteria. 



Klein recently described a microbe 

 obtained from swine-plague in Eng- 

 land which seems to resemble the 

 above bacterium in many ways. He 

 describes it as spore forming, however, 

 which is not true of the microbe un- 

 der consideration. Moreover, its 

 growth in various media, by which it 

 might be recognized, has not been 

 worked out yet. He describes its 

 growth in liquids, its motility, but 

 leaves us in doubt whether it liquefies 

 gelatin or not; how it grows in milk, 

 on potato, etc. He asserts that it has 

 no effect upon pigeons, but gives no 

 information as to the dose used. It 

 is therefore impossible to state at 

 present whether the two microbes are 

 the same, or whether two diseases 

 very much alike are caused by differ- 

 ent organisms. 



Muscle and Nerve in Sponges. 



BY DR. R. VON LENDENFELD.* 



Australian species of Eiispongia 

 show some unlikeness to common bath 

 sponge, E. officinalis. Massive, with 

 short, round, finger-like processes. 

 Each of these contains a wide cylin- 



* From Amer. Mag. Nat. Hist., 5 ser., vol. 17, p. 

 372. Orig. article in Sitz. Kiinig Preuss Akad., Ber- 

 lin, 1885, pp. 1015-20. 



