58o SCIENCE PROGRESS 



interfered with and the tissue lining them is destroyed. The 

 bird wastes away and ultimately dies. But there is another 

 factor in the case. When the degree of infection surpasses 

 I, GOG Strongyli in each caecum, there is no doubt a larger 

 increase in the Bacillus coli in the liver and in the lungs and 

 other organs. These bacilli do no harm whilst free in the 

 alimentary canal but when they pass the mucosa and reach 

 the other tissues of the body they undoubtedly serve to set 

 up various disorders. 



But the presence of these worms and also, I believe, to 

 a minor extent the presence of the transparent tape-worm in 

 the duodenum, has a further and indirect ill-effect on the 

 grouse. When hand-reared birds which were free from T. per- 

 gracilis were investigated, practically no bacilli were found in 

 the liver or other tissues of the grouse. When the birds 

 harboured from igg — i,ggg round-worms, bacilli occurred in 

 the tissues of about 50 per cent, of the birds — bacilli let out 

 from the cavity of the intestine " by a worm's pin-prick," to 

 quote Browning's "Lovers' Quarrel." When over 1,000 or 

 more worms were present, the bacilli, with one exception, were 

 found in the liver and in other organs of the body in lOO per 

 cent, of the birds investigated. The exact relation of these 

 bacilli to the sickness of the bird is still a matter of inquiry. 

 It seems as if they are soon absorbed and that no specific 

 disease is traceable to them, but if they exist in numbers their 

 products must exert a harmful influence. 



The existence of disease caused by the passage of these 

 bacilli through the walls of the alimentary canal through lesions 

 caused by tape-worms is less well established than through the 

 disorganisation of the lining membrane of the caeca caused by 

 T. pergracilis. On the other hand, one must not overlook the 

 fact that Hymenolepis is especially numerous in the spring and 

 autumn months, during which the greatest mortality takes 

 place, and is absent during the winter when the birds are 

 comparatively healthy. 



It is seen that the small number of colonies of Bacillus coli, 

 which can be cultivated from the tissues of a diseased grouse, 

 points to the fact that these bacteria do not multiply to any 

 extent in the tissues. Hence it would seem that no specific 

 disease is caused by the infection of these bacteria. The toxic 

 products of the bacilli, however, may be harmful, and should 



