OLD AGE. 



329 



A careful study of senile nerve cells has been made 

 by Hodge. 1 On examining the central system of a 

 man dying naturally at ninety-two years, very marked 

 changes were found in the cells of the spinal ganglia 

 when compared with those of the corresponding ganglion 

 taken from a child at birth. The principal differences 

 are summarised in Table 61. 



TABLE 61. SHOWING THE PRINCIPAL DIFFERENCES OBSERVED 

 ON COMPARING THE SPINAL GANGLION CELLS (FIRST 

 CERVICAL GANGLION) FROM A CHILD AT BIRTH WITH 



THOSE FROM A MAN DYING OF OLD AGE AT NiNETY-TWO 



YEARS. (Hodge.) 



The nuclei have decreased and become irregular in 

 outline. The nucleolus in many cases is not stained by 

 osmic acid, and the cytoplasm is much pigmented, but 

 these cells differ from those fatigued (cat) in that the 

 nucleus does not become darker than the cytoplasm. 

 In the cerebellum also there was an indication that 

 some of the Purkinje's cells had disappeared and others 

 were shrunken. 



Still more marked was the effect of age when the 

 nerve cells from the antennary lobe of the honey-bee 

 were examined. In old bees these exhibit a vacuolation 

 of the cytoplasm and shrinkage of the nucleus which 

 makes them quite comparable with the fatigued cells, 

 and very different from those of bees which have just 

 1 Hodge, Journ. of Physiol., 1894. 



