BLOOD 13 



changes in the cells of these structures. Certainly the hydropic 

 degeneration which is so frequently the essential lesion is not easy 

 to detect and is often masked by post-mortem changes. It has 

 indeed been suggested that this degeneration might result from 

 hyperglycsemia, and not be its cause. Allen has shown that the 

 change cannot be induced by causing prolonged hyperglycaemia 

 of alimentary origin in dogs. 



BLOOD 



This is not the place to follow out the ramifications of the trains 

 of thought of haematologists as to the origin of all blood cells from 

 one or more ancestral forms because there is still no sign of 

 unanimity ; the many text-books of hsematology can be consulted 

 by those interested in this rather barren subject. 



Lymphocytes. It is interesting that the first description of 

 mitochondria in lymphocytes was regarded as a very striking 

 haematological discovery because it was not realised that these 

 structures were identical with the similar ones observed in many 

 other varieties of cells. Schridde thought that the granules were 

 specific characters of lymphocytes ; so that he claimed to have 

 demonstrated a differential feature as between lymphocytes and 

 myeloblasts. It was presumably only the highly specialised 

 character of haematology that had prevented him from correlating 

 his findings with those of other microscopists : indeed, a valuable 

 demonstration of the folly of excessive specialization ! 



In connection with lymphocytes it were well to mention plasma 

 cells, because there is still some confusion as to the position of 

 these common elements. The essential characters of these cells 

 are : a relatively small nucleus in an excentric position ; the 

 chromatin often presents an arrangement resembling a cart-wheel ; 

 the fixed protoplasm has a granulated appearance and stains very 

 intensely with basic dyestuffs, but the part around the nucleus is 

 much paler. Furthermore there is a pallid area in the central 

 part of the cell in which suitable staining demonstrates the presence 

 of a number of centrioles. This is the typical plasma cell which is 

 now almost universally believed to arise from small and medium- 

 sized lymphocytes. The terminological confusion that exists is 



