1 86 R. R. BENSLEV. 



of the view that they represented the transitory phases of the 

 reciprocal nutritive inter-relations of the capsular and nerve cells. 



The object of the foregoing brief and incomplete resume of 

 the literature, has been to show that from three different lines 

 of investigation we have evidence of the wide occurrence in 

 animal cells, ranging in diversity from leucocytes to nerve cells 

 and muscle cells, of a reticular apparatus, which exhibits itself 

 in the form of a network of canals with colorless contents, or 

 of a stained network according to the technique employed. The 

 uniformity with which this apparatus has been discovered in 

 those types of cells in which it has been sought justifies the expec- 

 tation that similar methods will reveal similar structures in 

 cells which have thus far not been investigated with this point 

 in view. We are thus dealing with a cell organ of almost if not 

 quite universal distribution in animal cells. 



The question now arises What is the significance of this 

 structure? 



The trophospongium theory of Holmgren, as far as I am aware, 

 has found no support. Even if it were admitted for the nerve 

 cells there are many categories of cells in which a reticular ap- 

 paratus, or a canalicular apparatus is to be found, to which the 

 theory is wholly inapplicable. For example, it is difficult to con- 

 ceive how the reticular canalicular apparatus of the cartilage cells 

 and of leucocytes, could be derived from the liquefaction of pene- 

 trating processes of other cells. Holmgren, it is true, has made an 

 attempt to adapt his hypothesis to the canalicu ar apparatus of 

 epithelial cells, and has described in the pancreas of the sala- 

 mander the continuity of the intracellular network \vitli mtra- 

 cellular strands which go to the periglandular connective tissue 

 cells or to the centro-acinous cells. However, all of Holmgren's 

 figures of preparations made by the trichloracetic acid, resorcin- 

 fuchsin method are explainable on the basis of the canals having 

 a precipi table content which when precipitated by the fixative, 

 has an elective affinity for the dye. It is not by any means 

 certain that the figures which Holmgren has given us of intra- 

 cellular nets stained by fuchsin, in continuity with processes of 

 capsular cells, do not really represent two different structures 

 brought into apparent relation with one another by a common 



