ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 691 



at 18° to 22° C, forming upon gelatin plates flat spreading surface 

 colonies, which in two days attain a diameter of 1 to 2 mm., slightly 

 heaped up in the centre, with a sharply defined outline. Deep colonies 

 are small and punctiform, round, with a sharp contour, light edges and 

 dark centre. Stab and streak cultivations upon gelatin closely resemble 

 those of the jB. colt ; the organism does not liquefy gelatin. Cultivations 

 upon agar are by no means characteristic. Broth at 24 hours becomes 

 uniformly turbid ; later the growth sinks to the bottom as a sediment, 

 and leaves the bulk of the medium clear. Potato cultivations grow well 

 in about 24 hours. Cultivations in milk grow well at 20° to 22° C, and 

 in about four days show distinct red coloration, associated with a marked 

 acid reaction. The consistence of the milk is altered, and becomes 

 somewhat slimy, but does not undergo subsequent peptonisation ; the 

 depth of rose tint increases up to about the tenth day. The addition of 

 grape sugar to the milk causes the earlier development of a deep red 

 coloration (in two days) ; the addition of milk-sugar, however, does not 

 cause so marked a change. 



This bacillus is differentiated from the B. lactis erythrogenes by its 

 white growth upon gelatin and agar (as compared with the yellow 

 coloration and wine-red staining of the nutrient medium by the erythro- 

 genes), and by its intense slime formation in milk, associated with the 

 production of a red colour and an acid reaction without disintegration 

 of the casein, the B. lactis erythrogenes coagulating milk with an alkaline 

 reaction, producing a blood-red colour of the milk, and later peptonisa- 

 tion. B. jjrodigiosus and Sarcina rubra are easily differentiated from 

 the B. lacto-rubifaciens by reason of the coloured character of their 

 growth upon gelatin, agar, <vc. 



Black Dry-rot in Swedes.* — Middleton and Potter describe a bac- 

 terial disease attacking swedes, which they term " black dry-rot." This 

 disease takes the form of a dark, almost black, spot in the centre of the 

 turnip, which gradually increases in size till only a shell of normal 

 tissue may be left in the root. The organism responsible for the 

 disease was isolated by means of cultivations upon neutral turnip broth 

 rendered solid by gelatin, and when transplanted upon sterile blocks of 

 healthy swede produced a disease identical with that from which it was 

 originally obtained. The organism is a short, motile rod, 3 yu. by 1 /a. 

 It is an aerobe and liquefies gelatin, and possesses a single polar 

 flagellum, but no further specific characters have as yet been worked 

 out for this organism. 



New Syphilis Bacillus.f — De Lille and Jullien have isolated upon 

 ordinary nutrient media a new bacillus, both from the blood-serum 

 of a syphilitic patient, and from the serum obtained from blisters (raised 

 by means of cantharides plaster). This organism is a pleomorjmic 

 motile bacillus, 5-8 fx long by ■ 015 /a to • 03 /* broad, which retains the 

 colour when stained by Gram's method, and which in old cultures grows 

 out into threads, and later on becomes granular. When grown upon 

 agar it forms a creamy moist greenish layer, and it liquefies gelatin, 

 forming a light greenish pigment. 



* Journ. Board Agric, ix. (1902) pp. 25-32, 



t Centralbl. Bakt., 1" Abt., xxxi. (1902) Ref., p. 6 ; also Deutsch. Mel Woch., 

 1901, No. 29. 



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