g42 Dr. HANS GADOW, 



of tailwards. The pyloric portion of the duodenum makes a peculiar 

 curve upwards (see Fig. 5). Compared with that of other birds, the 

 gizzard of the Östlich is turoed over, round its transverse axis, to the 

 extent of about 150", pulled upon by the dilatation of the proven- 

 triculus. The latter has slided tailwards, past the dorsal and left 

 side of the gizzard, and has drawn the orifice of the gizzard with it. 



The cause of this enlargement and of the subsequent dislocation of 

 the stomach is obviously the amount of stones, which Ostriches swallow 

 during their life time. Most birds with a strong gizzard assist tri- 

 turation of the vegetable food by small stones, preferal)ly sharp edged 

 pebbles of quartz. They are however sparingly used, because they 

 seldom pass through the aliraentary canal, and they are not disgorged, 

 so far as I am aware. Only the Ostrich, and to a certain extent the 

 Nandu, take up stones in excess. The Ostrich has a regulär idiosyn- 

 crasy for almost any absolutely indigestible matter. Garrod found 

 in the stomach of an adult male more than half a gallon of stones 

 (about 7 Ibs. in weight); „most of them were about the size of cob- 

 nuts or peas; they fully dilated the organ and pulled it down ab- 

 normally". I found in another specimen about 4 Ibs. of gravel, the 

 Sandy detritus mixed with pebbles and being located in the blindsac 

 of the proventriculus. The food rests on the top, and the finest 

 detritus sinks down lowest. Comparatively few stones, mostly sharp, 

 and hardly any sand occur in the gizzard, where alone they can assist 

 the grinding process. 



This condition is not abnormal, and is not the cause of death of 

 Ostriches kept in captivity. All Ostriches hitherto examined, exhibited 

 the same features. Moreover the examination of a number of em- 

 bryonic and of very young Ostriches, collected by Mr. Sedgwick at 

 Ostrich-farms at the Cape, assisted by a grant from the Royal Society, 

 show that the dilatation of the proventriculus, and the reversion of 

 the gizzard are already present long before the stomach contains any- 

 thing but foodyolk. 



Fig. 18 represents an Ostrich embryo with the intestines in situ, 

 after removal of the sternum, the right wall of the trunk and the 

 liver. The heart has been affected in its position by the turning of 

 the gizzard. Nearly the whole of the intestinal canal is shoved to- 

 wards the right and dorsal side; the same is the case in the adult, 

 and in such birds in which, -e. g. Cormorant, Heron, the thinwalled and 

 very elastic stomach is so large that its fundus reaches into the neigh- 

 bourhood of the anus. 



