PHYSIOLOGY AND ANATOMY OF EED GROUSE 117 



infested with Trichostrongylus both the external and the internal appearance 

 become quite altered (see PI. xxx., Figs. 2, 3, 4, and Figs. 5, 6, 7, 8, 9). 

 In this Plate, Fig. 2 shows the caecum much swollen with the mucosa thickened 

 and congested, and the mesenteric vessels engorged, the mucosa show a little 

 red, punctiform inflammation from the injected villi, otherwise the colour is grey 

 and the ridges are tumid and much swollen. Figs. 3 and 4 show the caeca much 

 congested, and the meseuteric vessels engorged with dark venous blood. Fig. 5 

 represents an exceptional appearance, the four greater and four lesser ridges are 

 well defined, there is no trace of nodules, but there is slight inflammation. 

 Fig. 6 shows the interior of the lower end of the caecum, and Fig. 7 shows a 

 section of the middle third, in both these examples the mucous membrane is 

 much congested, and hypertrophied with fully injected red villi. Figs. 8 and 9 

 show the appearances in a bad case of Strongylosis. 



Other extreme cases of Strongylosis are shown on PI. xxxi., where Fig. 1 

 represents a portion of the caecum at the junction of the lower and middle 

 thirds. Fig. 2 shows a similar appearance in the middle third. Fig. 3 illustrates 

 a section of the first third intensely congested, while Fig. 4 shows the same when 

 magnified under a 1-inch objective. In Fig. 5, showing a section between the 

 lower and middle third, there are large spaces with no trace of ridges ; but 

 it is probable that this is the effect of post-mortem change. 



Instead of an intestine of a brownish or greenish grey colour moderately filled 

 with soft brown pasty material, and showing greyish yellow lines running down 

 its length on the outside, indicating the eight or nine long villous Appear- 

 ridges within, we see in the caecum of a diseased bird a distended tube, unhealthy 

 with overfull and congested blood-vessels ramifying over it on the 08eca - 

 outside, standing out very often in conspicuous contrast with a yellowish fatty- 

 looking gut-wall ; or the whole substance of the wall of the caecum may be 

 congested to a deeper tone, and may look dark, blue - black, and unhealthy. 

 Before opening the gut, however, the congestion of the mesenteric vessels is 

 the most conspicuous point. This is due to a venous congestion, and it means 

 that the liver and other abdominal viscera and the right side of the Li vera nd 

 heart are overfull. The liver may be very dark. It decomposes heart - 

 rapidly, becoming of a black, tarry, soft and very rotten consistency ; but this 

 is not a safe indication of disease. The difference in appearance between a 

 healthy liver during decomposition and a diseased liver is so uncertain that, 

 after a day or two of summer heat, it becomes impossible to judge whether 



