Practical Hints. 131 



duct of Wirsung without bifurcating. In all other respects 

 that case seems to be identical with the one just mentioned. 



So far as I know, this anomaly has been found only in the 

 domestic cat. Its reported presence in the common seal {Phoca 

 litulina) by Cuvier (5, 587), Salter (27, 99), and Milne-Edwards 

 (22, 511) is probably an error ; for Fr. Tiedemann (32,297), to 

 whom they refer for their authority, states that the duc- 

 tus choledochus, after entering the duodenal wall dilated be- 

 tween its coats forming a larger reservoir, into which emptied 

 the pancreatic duct. He says of this reservoir that it bears 

 great resemblance to that which appears in the gall-duct of 

 the elephant as described by Pierre Camper (39). Owen 

 (23, 480) and Miall and Greenwood (40) say of the elephant: 

 '•'There is no gall-bladder, but the ductus choledochus expands 

 in the wall of the duodenunj into a sacculated pouch, which 

 receives also the first pancreatic duct:" and Prof. Owen says 

 of the seal {Phoca lituIina) dissected by him: ''The ductus 

 communis was one and a half inches long ; it was joined by the 

 pancreatic duct as it terminated in a dilated sacculus within the 

 duodenal coats," (23, 487). It seems to me evident from all the 

 above that Tiedemann simply referred to a large ampulla of 

 Vater (See PI. XII.. Fig. II.. 6. and PI. XIV., Fig. i). 

 ( To be continued.) 



PRACTICAL HIXT5 OX PREPARIXG AXD MOUXT- 

 IXG AXIMAL TISSUES. 



BY CARL 5EILER, M. D. 

 {Received December 6th, 1878.) 

 At first glance, it seems superfluous to add to the already 

 extensive literature on practical microscopy, and one might 

 think that such books as Beale's, Frey's, etc., could not be 

 improved upon. Yet there are certain little details of manip- 

 ulation, which are not generally described in larger works, and 

 which, if they do not insure success, at least facilitate the 

 working of the different processes. I shall, therefore, as briefly 

 as possible, give a description of the method which, by per- 

 sonal experience, I have found to give the best results in pre- 

 paring animal tissues for microscopical study. 



HARDEXIXG. 



With most tissues it is necessarv to make a thin section, so 



