41 



THE NERVOUS TISSUES: -THE PERIPHERAL NERVOUS 



SYSTEM. 



LABORATORY WORK FOR THE WEEK. 



References : 

 Points for Quiz : 

 Laboratory Report : 



Due ; 



Go to the delivery desk for («) assigned slide, 73 ; (J>) paraflBn 

 sections, 74, 75, 76, 77, 78 ; {c) 72, stained ; now in clearer; tease 

 as directed below and mount in balsam ; (a?) 70 and 7 1 may be pre- 

 pared while the parafi&n sections are being carried through. 



NERVE CELLS. 



70. From the myel (Spinal cord). Calf. The myel was 

 split lengthwise and placed in formaldehyde dissociator (§§ 8 and 9). 

 Place a small piece of the grey matter upon a slide in a drop of ^% 

 eosin (§ 94), and proceed as directed in § 10. 



Search the preparation carefully until you find a nerve cell with 

 quite long processes (dendrites). Observe (a) the nucleus with its 

 nucleolus, {b) the number, extent, and branching of the processes 

 of the cell-body, (r) the structural appearance of the cell-body and 

 its processes. Can you determine the identity of the neurite ? If 

 desired, you may be shown nerve-cells in section stained with 

 methylene blue, for Nissl's corpuscles. 



71. From the cerebral cortex. Cat. The hippocamp was 

 cut up into pieces and placed in formaldehyde dissociator. Care- 

 fully prepare two or three preparations according to § 10. The best 

 preparation may be retained as a permanent mount. 



Examine the slide carefully, finding as many cells with long 

 processes as possible. Compare with 70, recognizing the identity of 

 structure of the cells, but observe that these cells are of a pyramidal 

 form, with a long apical process and basal processes. Can you find 

 the neurite springing from the base of the cell ? 



