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G. H. F. Nuttall and D. Keilin 
They are more elongated and are more or less fused in a chain-like manner, the 
terminal nephrocyte being either fused with the fat body or connected there¬ 
with by means of a long filament. 
The Physiological Function of the Nephrocytes. 
The cytological structure of the nephrocytes we have considered above, 
strongly resembles that of the pericardial cells of other insects as already 
pointed out by Muller. It is therefore natural to ask if the function of these 
cells is not similar to that of the pericardial cells. With a view to replying 
to this question it is necessary to dwell upon what is known regarding the 
physiological function of pericardial cells. 
Kowalevsky (1886) was the first to show that in Dipterous larvae, fed 
upon artificially coloured food, the pericardial cells become stained more or 
less intensely. He also showed that the colouring substances he employed, 
namely cochineal powder and silver salts, become deposited in the protoplasm 
of the pericardial cells without, however, staining their nuclei. 
In 1889, Kowalevsky, moreover, showed that these cells are capable ot 
eliminating certain substances introduced into the body either (a) directly bv 
injection into the body cavity, or (6) indirectly through the alimentary canal, 
and, since the cells do not possess an excretory duct, they store throughout 
their life the substances which they take up. 
