E. MARSHALL!. — ARCH^OCYTES. 167 



The arch«;ocytes are apparently simply attached to, or sus- 

 pended by, the trabeculoe. At other times, they are seen adhering 

 to the outer (incurrent) surface of the merabrana reticularis. 

 From their sliape and the manner of their occurrence, it is 

 out of question that we have to do witli epithelial cells. 



There seems to exist a certain limitation to the sphere of 

 tlieir distribution. I do not remember having ever met witli 

 them in the dermal or the incurrent canalar membrane, nor in 

 the entire inner trabecular system. If they occur at all in these 

 parts, it must be exceedingly seldom. On the wide-stretched 

 trabeculte running in the wider incurrent spaces, they are found 

 only here and there sparingly and at irregular intervals. They 

 are seen attached to the trabecule mostly singly, at times two 

 or three in close succe.ssion. In proximity to the chambers they 

 become more common and are usually quite abundant on the 

 outer surface of, as well as in the narrow incurrent interspaces 

 between, the chamber- walls (PI. V, figs. 30, 37, 43 ; arch.). Here 

 they occur either solitarily or in irregular groups of two, three, 

 and so on, up to tens and in certain positions even to hundreds or 

 tliousands. But the usual size of the cell-groups, as it presents 

 itself fairly constantly on all chambers in irregularly scattered 

 distriijution, is small, consisting of, say, not more than about 

 twenty or thirty cells. In PI. IV, fig. 28, I have indicated such 

 small groups of archteocytes by irregular dots on the chambers 

 (see also PI. VIII, fig. 29). In these small groups the cells 

 are usually, though not always, found arranged side by side 

 in a single layer, lying fiat upon the chamber-wall. It is also 

 the rule that we meet with the archceocytes, whether lying 

 singly or in patch-like groups, in greater abundance where the 

 opposite walls of any two contiguous chambers approach nearest 



