188 POST MORTEM EXAMINATIONS 



injury to the spinal cord) will remove the spinous processes in the form of a 

 rosary held together by the ligamenta flava. 



If there is any meningeal exudate, cauterize the surface of the membrane, 

 introduce a pipette through the centre of the cauterized area and aspirate 

 the fluid. 



To remove portions of the nerve tissue tear through the meninges with 

 two pairs of forceps, cauterize the area (cerebrum, cerebellum, medulla 

 oblongata or spinal cord), and push the point of a strong pipette deeply into 

 the tissue ; then aspirate the material, twisting the pipette about if necessary. 

 Or, after cauterization, portions of tissue may be removed with a platinum 

 loop or with a sterile bistoury. 



B. Birds. 



To open the thorax in birds it is best to divide the skin along the middle 

 line, and after reflecting it to each side to make a curved incision, extending 

 to the bone, round the sternum ; beginning at the root of the neck, con- 

 tinue along the right margin, round its lower end and up the left margin. 

 Cut through the clavicle on each side with a pair of stout scissors, and 

 following the line of the incision through the soft parts detach the sternum 

 from the ribs, then cut away the muscular attachments and remove the 

 breast plate. 



The examination will then be proceeded with as in the former case. 



C. Post-mortem examination of human bodies. 



The technique to be employed in the collection of material post mortem 

 from the human subject does not differ from that already described in the 

 case of animals, and the methods of examination should also be the same, 

 but it must be remembered that if the results of the bacteriological 

 investigation are to be relied upon the examination must be made within 

 a few hours of death ; if it be delayed until the interval required by law 

 has elapsed (24 hours after death) the bacteriological findings must be 

 accepted with caution especially in summer; the presence of -the colon 

 bacillus in particular in the internal organs would be under such circum- 

 stances without significance, since this organism multiplies in the tissues of 

 the body immediately after death and sometimes even during the period 

 immediately preceding death. 



Note. The material collected post mortem may either be examined and sown at 

 once, or may be put aside for examination at a later stage, provided that both ends 

 of the pipettes containing the material be sealed. In the latter case to reach the 

 contents of a pipette, push down the wool plug almost as far as the top of the fluid, 

 and cut off the part of the pipette above it with a glass-cutter and a point of red 

 hot glass ; the plug can then be taken out and the contents manipulated with a 

 pipette just as in the case of a culture- tube. 



5. Removal of tissues for histological examination. 



For purposes of subsequent histological examination, small pieces of the 

 internal organs [and other tissues] should be removed at the time of the post 

 mortem examination. The pieces should be quite small (cubes of 10-15 mm.), 

 but should be cut off with a sharp sterile bistoury so that the section may 

 be as clean as possible. Place the pieces at once in ground-glass stoppered 

 bottles containing one of the following fixing solutions : 



1. Absolute alcohol. For bacteriological purposes absolute alcohol is the 

 simplest and the most generally useful fixative. 



The method of placing the tissue in the first instance in weak alcohol and 



