Turner, Morp/ioli\^-v of tlic Avian Brain. 133 



soin\ to show the appeai-ance of the cells when the nidiilus is cut 

 obliquely. 



^iff- 12. Section of tectum of the caudad portion of the optic lobe 

 of Hylociclila s-vainsoui . 



Fii^-. l.i. Cells of the nidulus of the fourth nerve, from Sialiu 

 si alls. 



fiii- 14- Cells of the nidulus of the third nerve, from Sia/id s/(i//s. 



NOTES UPON TECHNIQLTE. 



The following suggestions may prove useful to others as 

 they have to us. 



I. Felt-tipped Pliers. — Every one has experienced the 

 difficulty of using pliers or forceps of the ordinary pattern in 

 handling delicate and slippery tissues. If the corrugations 

 are sufficiently sharp to be of service there is much danger of 

 lacerating or perforating the membrane. This is true in the 

 dissection of amphibia with mucous glands in the skin as 

 well as in the mucous and serous membranes of other verte- 

 brates and the meninges of the brain. This difficulty may 

 be almost entirely obviated by gluing to the points accurately 

 fitted pieces of close-textured felt or chamois skin, which 

 facilitate steady and firm tension without danger of lacera- 

 tion. 



3. KuLTSciiiTZKv's HEMATOXYLIN PROCESS. — A method 

 which possesses many of the advantages of Weigert's, be- 

 sides being shorter and more simple, is described as follows: 

 The material is fixed in Erlicki's fluid one to two months 

 and is then washed in flowing water one to two days. The 

 precipitation of chromium salts, which is one of the great 



