4 CELL-ORGANS 



alcohol ; this moiety can be stained with osmic acid. Most of the 

 methods for the demonstration of the Golgi apparatus are based 

 on the observation that, after suitable modes of fixation, a great 

 affinity for silver is developed. 



Usually the Golgi apj^aratus is a fairly dense network of anasto- 

 mosing strands. Even in adjacent cells its shape is different, 

 presumably as an indication of great functional plasticity. In 

 spite of such differences, it can be said with certainty that in a 

 general way the form of the Golgi apparatus is fairly typical of the 

 special cell type. Any variations of structure seem to be related 

 to functional peculiarities in the cells in question ; thus there 

 is a generic similarity in the Golgi apparatus of the pancreas of 

 different animals, and the same applies to its appearances in many 

 other organs. 



The great majority of animal cells contain a Golgi apparatus, 

 although of very varying degrees of complexity ; in some formed 

 elements, for example red corpuscles, no trace of the network can 

 be found. Indeed there seems to be some evidence that the 

 apparatus is found only in cells engaged in or capable of active 

 functional manifestations. It is presumably for this reason that 

 the cells of developing embryos supply the most admirable 

 material for the study of the Golgi apparatus in its most typical 

 forms. 



More details of the appearances of the structure in special organs 

 will be found later, but some general remarks are not out of 

 place at this stage. There seems to be some relationship between 

 the position of the Golgi apparatus and the functional characters of 

 the cell in which it lies, although alteration in the position of 

 the cell, and therefore presumably of the mode of activity, is not 

 always accompanied by a redistribution of the Golgi apparatus ; 

 thus, in ectodermal cells, these structures lie between the nucleus 

 and the periphery of the cell body ; and even when the tissue is 

 reversed, as during the formation of the optic cup, this relationship 

 persists. In cells which always secrete in the same direction as, 

 for example, those of the pancreas, the apparatus lies between the 

 nucleus and the glandular lumen ; but in the thyroid, at least in 

 the guinea-pig, it appears that the structure can migrate from one 



