. Fig. 14. Various stages in the flexions and transverse divisions of Treponema (Spirochoeta gallinarum). (Hindle) sion. This is accomplished only after a series of movements con- sisting of doubling back on itself, coiling of the two portions, un- coiling and eventual separation. The process is illustrated in Fig. 14, the successive stages of the process being indicated by the let- ters a to h. Sometimes the separation occurs as illustrated in e, but usually takes place after the position h is reached. Whether or not transverse division takes place directly without previous flexion has not be
. Fig. 14. Various stages in the flexions and transverse divisions of Treponema (Spirochoeta gallinarum). (Hindle) sion. This is accomplished only after a series of movements con- sisting of doubling back on itself, coiling of the two portions, un- coiling and eventual separation. The process is illustrated in Fig. 14, the successive stages of the process being indicated by the let- ters a to h. Sometimes the separation occurs as illustrated in e, but usually takes place after the position h is reached. Whether or not transverse division takes place directly without previous flexion has not been definitely determined. The act of uncoiling and sep- aration as illustrated in d, f, and g of Fig. 14 very closely sim- ulates a process of longitudinal division and has been erroneously so interpreted by some observers. The process of transverse division doubtless occurs repeatedly in the blood. Penetration of red blood cells and invasion by spirochetes has been observed but seems to be uncommon. At the time of the crisis of the disease, which is synchronous with the disappearance of spirochetes from the circulating blood, some spirochetes break up into a number of coccoid bodies in a manner analogous to the formation of spores within a bacterial cell. It is not certain that these coccoid bodies formed under the conditions in question redevelop into spirochetes within the blood of the fowl. Some of the spirochetes taken into the tick with a feeding of fowl blood, penetrate the wall of the gut and gain access to the coelomie fluid which occupies the body cavity of ticks. After a short time
Size: 2449px × 2042px
Photo credit: © The Bookworm Collection / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1920, booksubjectbirds, booksubjectpou
