Ascococcus. 



15 



[21. M. toxicatTis, Burrill {I.e., p. 319). 



Cells globular, single or in pairs, rarely in chains, "5 /«. 

 in diameter ; movements oscillatory only. 



In species of Rhus (Sumach), believed to be the 

 peculiar " poison " for which these plants are noted. 



Transferred to the human skin, they multiply rapidly, penetrate 

 the epidermis through the sweat-glands (?), and set up the well-known 

 inflammation.] 



II. ASCOCOCCUS, Cohn (« Beitrage," i. p. 154). 



Cells colourless, very small, round, united in enormous 

 quantity into larger or smaller, globular or irregular /«»«'//«. 

 Families often folded, the folds again crimped, surrounded 

 by a firm, cartilagino-mucous capsule of a rounded form. 



The value of Cohn's genus Ascococcus is, in my opinion, just as 

 questionable as that of the similarly named one of Billroth ; it is besides 

 doubtful whether or not they are identical. Possibly Ascococcus is only 

 a stage in the development of Micrococcus. 



h ,'— -. 



22. A. Billrothii, Cohn {I.e., p. 124). 



Families lump-like, 20-160 /* in diameter, 

 surrounded by a capsule as much as 15 /;i. 

 thick, covering the surface of the fluid in 

 a thick floccose layer. (Fig. 7.) 



Forming a membrane on a solution of 



acid' tartrate of ammonia. 



The colonies consist of a well-defined cartilagino- 

 mucous colourless envelope, in which either only 

 one or several families are enclosed. The families 

 are of very varied size and form, solid, composed 

 of numerous extremely minute round cells. The 

 Fungus produces in its nutrient fluid a peculiar 

 decomposition; it generates out of the ammonic tartrate contained 

 therein butyric acid and butyric ether, and changes the originally acid 

 fluid into an alkaline one, while free ammonia is evolved. The liquid 

 has then the characteristic smell of milk or cheese. 



Fig. 7. — Ascococcus 

 Billrothii (after 

 Cohn). I, the in- 

 vesting capsule. 



