. British bee journal & bee-keepers adviser. Bees. 132 THE BRITISH BEE [April 6, 1899. Oil iniin. media is right, such as appears in fig. 2 (page 123), in which the various colonies of germs can be distinctly traced, mostly crowded together, but often in an isolated condition, as seen in fig. 4. From three to four days later the growth appears as in fig. 3. If a portion of this growth is now re- moved and placed under the micro- scope, only rods will be found, all spores from the original specimen having germinated. Some media results in longer rod-shaped forms than others ; amon
. British bee journal & bee-keepers adviser. Bees. 132 THE BRITISH BEE [April 6, 1899. Oil iniin. media is right, such as appears in fig. 2 (page 123), in which the various colonies of germs can be distinctly traced, mostly crowded together, but often in an isolated condition, as seen in fig. 4. From three to four days later the growth appears as in fig. 3. If a portion of this growth is now re- moved and placed under the micro- scope, only rods will be found, all spores from the original specimen having germinated. Some media results in longer rod-shaped forms than others ; among these latter may be mentioned the fluifl forms of media, such as broths, liquefied gelatine, and the moisture found at the bottom of tubes containing agar - agar, all these giving a great majority of long forms. On the other hand, samples cultivated from potato or on the solid parts of agar, &c., produce short, and, in my opinion, the most virulent cf the rod-shaped forms. It will also be noticed on examination that these short rods are far more active than the longer ones seen in fig. 6. Still longer rods are shown in fig. 7 ; while the manner in which the rods split can be well seen in both figs. 5 and (!. Jf some of the tubes be now placed in a temperature of 100 deg. to 104 deg. and examined in twenty-four hours, a large number of spores will be found, and if the same temperature is con- tinued for a day or two or raised to 110 deg. Fahr. for twenty-four hours the bacilli will have either spored or been destroyed. Again, if the cultures are allowed to cool to 45 deg. Fahr. or below, the same phenomena takes place, , the bacilli are destroyed and a large number of spores are rapidly formed. It will thus be seen that there is a specialised temperature most favourable to the life of the bacilli or active form of the disease, and directly this limit is exceeded either on the upward or downward scale the disease becomes latent. But spores remain, and these are prac- ti
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