CELL THEORIES. 



were never used except when it was meant to 

 predicate the existence of a cell-wall. 



For some years past I have, in teaching, been 

 particular in this matter of nomenclature, believing 

 that misleading names do generate confused ideas, 

 and that no conventional compact can make it 

 judicious to designate a solid mass by a word 

 which indicates a hollow vesicle, or advisable to 

 use a common word in a sense at variance with its 

 usual meaning. It ifr as if we were to invest the 

 tongs with the scientific name of poker. " There 

 is nothing, I can assure you, gentlemen," said 

 Goodsir, "which has more retarded science and 

 philosophy, and the kindred subjects on which 

 human reason has been employed, than the intro- 

 duction of terms with conventional meanings." 

 But I admit that it is difficult to escape from an 

 accustomed groove, and that for a time one must 

 be content, under protest, to speak occasionally of 

 secreting cells, nerve-cells, hepatic cells, and so 

 forth ; were it for no other reason than to be in 

 harmony with the language of text-books, in speak- 

 ing to students. 



The changes in the anatomical conception of the 

 living corpuscle have not been without their influ- 

 ence on the physiological conception. In the days 

 when the cell-wall was paramount, it seemed an 



