ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 1015 



The first of the new species, B. carotarum, was found on the root of 

 a carrot which had been boiled and left under a bell-jar for two 

 or three days. It forms long threads, which become more or less 

 twisted, especially if grown on beet-root, when they bear great resem- 

 blance to Spirillum. It bears endogenous spores, and when in this 

 condition is very similar in appearance to B. tumescens ; indeed, both 

 these bacilli were found in an approximately pure state on the boiled 

 carrot. 



The spores of B. carotarum are invested in a membrane which on 

 germination is burst about its equator by the young rod. These, in 

 drop-cultivations, grow rapidly to long filaments, which are always quite 

 motionless. The filaments, which are, while young, straight, afterwards 

 become curved or angularly crooked. They are composed of a number 

 of segments separated by transverse septa only visible by the aid of 

 reagents. The next step after the full development of these filaments is 

 the production of spores, and these are oval bodies l* 31-2 '38 /a long 

 and 1*03 /x broad, placed at regular intervals along the filament. 



In addition to drop-cultivations colonies were grown on gelatin, 

 meat infusion, potato, &c. With regard to the rate of growth, the 

 author found that B. carotarum doubled its length at 30°-33° C. in 

 forty-three minutes, at 40° C. in eighteen minutes, and 45° in twenty- 

 two minutes. 



Heating the spores in the dry state was unable to weaken, much less 

 to destroy, their germinating power, although they were exposed for 

 eight hours to 100°, and in some cases four hours to 120° C, and it was 

 also determined that air was necessary to start their development. 



B. tumescens Zopf. — Besides B. carotarum another endosporous Bac- 

 terium forms white colonies upon the boiled root of carrot. The oval 

 bright-looking spores soon swell up in a nutrient medium, and, bursting 

 through the spore membrane equatorially, develope into rods which 

 eventually become irregularly bent. When young the individuals show 

 a certain amount of movement. One of the peculiarities of B. tumescens 

 is that in the adult condition the individual elements measure more in 

 breadth than they do in height, that is, measured on the long axis of the 

 filament (breadth = 2"1 /x, height = 0'8-l'5 /x,); and another is that 

 frequently amidst a chain of cells one will be seen without a spore. 

 B. tumescens grows luxuriantly on solid media, potato, carrot, gelatin 

 plates, &c. It rapidly liquefies the gelatin. 



B. inflatus nov. sp., found by chance as an impurity in a drop- 

 cultivation, is distinguished by swelling up, so as to assume a lozenge 

 shape, when about to sporulate. The spores are fusiform or bean- 

 shaped, have no definite disposition as regards the cell-axis, and may be 

 two in number. When germinating they escape through an aperture 

 about the middle of the cell. It is only grown with certainty in drop- 

 cultivations in a 1-2 per cent, meat infusion. In large quantities of 

 nutrient medium it grows well, and also on potato. Cultivated on gelatin 

 the colonies are spheroidal ; the gelatin is slowly liquefied. 



B. ventriculus nov. sp., like B. inflatus, was discovered as an 

 impurity, and resembles that bacillus in every respect except the ar- 

 rangement of the individuals in drop-cultivations and in its manner of 

 growth on potato. These differences are considered sufficient by the 

 author to form a basis of distinction between the two species. 



The Bacillus alvei Cheyne and Cheshire, which forms spores in an 



