206 



MR. R. H. BURNE ON THE 



the chief lamiiise are occupied by others of less height, consti- 

 tuting according to their size and position secondary, tertiary,., 

 and quaternary series. 



The position and height of the different series are shown to scale^ 

 in the accompanying diagram (text-fig. 23). It is to be noticed 

 that of the quaternary series those only interposed between tlie 

 secondary and tertiary series are represented by definite laminse. 

 Those between the tertiary and primary, when they are repre- 

 sented at all (and they apparently are not in every case), ar& 

 indicated only by a row of minute papillfe (text-fig. 23, j»,), as 

 the whole quaternary series is in the Giraffe and certain other 

 Ruminants*. 



Text-figure 20. 



Text-fiffure 21. 





Text-fig. 20. — Papillaj of rumen, X 2. 

 Text-fig. 21. — Cell of reticulum, nat. size. 



Text-figure 22. 



CES.G i- 



Specialised papillae of resophageal gutter, nat. size. 

 I., lamina of psalterium ; ces.ff.. roof of oesophageal gutter. 



Towards the oesophagus the laminae gradually fade away, and 

 are succeeded bj- rows of enlarged papillae similar in character but 

 not in size to those that cover the surface of ail the laminse. Some 

 of these papillae are enormously developed (text-fig. 22) and form,, 

 when the cesophageal gutter is closed, a coarse filter to prevent 

 unsuitable food from passing into the psalterium. 



Papillae similar to these, though fewer in number and smaller 

 in size, are present in the stomach of the adult Ox, at the entry 

 of the cesophageal gutter into the psalterium. 



* Garrod, Proc. Zool. Soc. 1877, p. 5. 



