9 



sediment is heavy, and turbidity very marked, but no pallicle. In 48 hours, 

 the media is opaque and cloudy, and the pellicle is beginoing to form. In 

 96 hours the broth ia less cloudy, but the sediment is heavier, and a white, 

 thick pellicle is formed. It is often wrinkled, but not quite so much so as 

 that on the glycerine broth. Reaction of broth after 10 days' growth, +4.6. 

 The bacilli are occasionally clubbed and y-like forms may occur. They aver- 

 age 6 // in length and may be slightly curved. 



Lactose Bouillon. — With a reaction of +1.06, at 37° C, the growth re- 

 sembles that of plain bouillon for the first 24 hours ; but at the end of 48 

 hours, it is more turbid. In 96 hours, a tenacious pellicle forms, less massive 

 than that on Glucose broth. Reaction after 10 days' growth, + 2.4, The 

 bacilli average 3,5 /< in length. 



Saccharose Bouillon. — With a reaction of +1.0, at 37° 0., the turbidity 

 and sediment are heavier than any of the other bouillons. In 48 hours the 

 broth 'is quite opaque and whitish looking. A heavy sediment is then present 

 and pellicle formation is just beginning. In 96 hours, the cloudiness is about 

 the same, but there is an increase of sediment and the pellicle is thin and 

 membranous. Reaction of media after 10 days' growth, + 4.04. The 

 bacilli average 5 /< in length. 



Gelatine Plates. — At 22° C. in 24-86 hours, the colonies are small, 

 round, oval, or lozenge-shaped, with peculiar projections or shoots from one 

 end of the colony, giving it a pear-shaped, or tadpole-like appearance, accord- 

 ing to the amount of development of the projection. In many cases, several 

 of these outgrowths occur from different portions of the colony. By placing 

 a cover glass on the surface of the gelatine and using objective 7, the bacilli 

 may be seen moving around and around the colony and to and fro along the 

 projections. At the end of 48 hours, the colonies are larger. Fine pro- 

 cesses or projections are shooting out into the gelatine in all directions, form- 

 ing peculiar figures in circles or club-line forms. " It is impossible," says 

 Oheyne, " to give a proper idea of the appearance of the growth. The forms 

 assumed are the most beautifully shaped I have ever seen ; but they are very 

 numerous, always retaining the tendency to form curves and circUs." After 

 a time the gelatine is liquefied and the beautiful appearance of the colony is 

 deslroyed by the liquefaction of the gelatine. 



These peculiar shaped colonies are most typical when the germ is taken 

 from the diseased larvae. After prolonged cultivation on various kinds of 

 media, there is a tendency for the r^olonies to become round, and the peculiar 

 branching forms are not seen in such numbers. The composition of the gela- 

 tine also seems to make a difference in the appearance of the colonies. In 

 gelatine containing 12 per cent, sfelatine the processes are not so long. The 

 same effect may be brought about by using more peptone in the composition 

 of the media. 



Gelatine Tubes. — In stick cultures at 20° C. growth occurs all along the 

 line of puncture. On the surface, delicate branching or ramifying growth 

 occurs in three days. These outgrowths soon run together and the gelatine is 

 liquefied, first around the line of puncture, and in 5 days extends over the 

 ■whole surface. The growth in the depth of the gelatine occurs as a whitish 

 streak all along the needle track ; and from this, numerous shoots and 

 growths branch out into the gelatine in all directions, giving a haziness to 

 the appearance of the gelatine, which then begins to liquefy. If the inocula- 

 tion is a heavy one, the f'hoots are coarse and may have club shaped extremi- 

 ties, and from these swollen ends fresh shoots may start. Oheyne obtained the-' 

 most characteristic growth in gelatine containing 3 per cent, of peptone, as well 



