324 THE GROUSE IN HEALTH AND IN DISEASE 



identity or otherwise. Dr Sambon also thinks that lice might act as "alternative 

 hosts " for the Spirochaetes. I will return to the subject of transmission later. 



S. lagopodis is from 10 M to 18^ long, and is relatively broad for this class of 

 organism. In life it moves actively in the blood of the host, spirally boring its 

 way between the corpuscles. S. lagopodis also often entwines one part of its body 

 about the other (Fig. 31). The organism usually has tapering ends (Figs. 29-40). 



Though the Spirochaete is small, stained specimens show a fair amount of 

 structural detail. A narrow undulating membrane (Figs. 29-36) is present, and 

 passes spirally round the body. The thickened border of the membrane stains 

 bright red with Giemsa's stain (Figs. 29-34), and even when the membrane is 

 closely contracted round the body of the Spirochaete, the border can be distinguished 

 as a bright line (Figs. 30, 32). 



The chromatin of the Spirocheete is distributed in the form of bars throughout 

 the body (Figs. 29-35), and at times these chromatin bars become joined and form 

 a helicoid core (Fig. 36) traversing the entire length of the body. This latter con- 

 dition is comparatively rare. A basal granule is present at either end, and near 

 these granules the membrane is attached. Longitudinal division is usually initiated 

 by fission of the basal granules. 



Multiplication of S. lagopodis takes place by both longitudinal and transverse 

 division. In longitudinal division rather thick Spirocheetes divide (Fig. 40), the 

 split extending gradually from one end, and the daughter forms diverging more 

 and more until final separation occurs. Transverse division takes place in relatively 

 long organisms (Fig. 35), and two daughter forms are produced. The parent organism 

 elongates somewhat during the division. Very minute forms (Fig. 39) about 4 M 

 long are the product of repeated divisions in both directions. Small forms have 

 been seen in the spleen (Figs. 38, 39). By reference to growth following division, 

 all the variations in size and form exhibited by S. lagopodis may be explained. 



Regarding the mode of transmission of S. lagopodis, it seems to me that the 

 nymphs of Ixodes ricinus, that sometimes infest Grouse, may be the carriers of the 

 Spirochsetes, for in the gut of nymphs of Ixodes ricinus taken from Grouse, I have 

 found Spirochaetes which may be S. lagopodis. During my investigations, I have 

 dissected many Mallophaga, both Nirmus cameratus and Goniodes tetraonis, but 

 have not found Spirochaetes, though the sperm of these lice are deceptively like 

 Spirochaetes at first sight. Dr Sambon has suggested that lice act as transmitters 

 of the Spirochaete that he found in feather-pulp. This is possible, and as a matter 

 of fact, evidence is accumulating and tending to show that the carrying of disease 



