lO ANDREWS. [Vol. II. 



in Flemming's fluid and not stained, were kindly placed at my 

 disposal by Professor T. H. Morgan. Both those mounted in 

 balsam and those studied in alcohol showed undoubted filaments 

 connecting the blastomeres in various cleavage stages. From 

 the resemblance of these filaments to those found in preserved 

 echinoderm material there seemed little doubt that this was 

 probably another case of filose intercellular connections, but 

 there must remain some doubt till the live Q.g% is studied. In 

 living material we may expect to find filose displays as remark- 

 able as those in the echinoderms, and, in part at least, more 

 readily observed. 



In four, eight, and sixteen-cell stages, many eggs showed 

 such marked intercellular connections as the one represented 

 in Fig. 4. These filaments are of clear material that arises 

 from the clear ectosarc of one cell and becomes continuous 

 with that of another cell. Only a few cases of branching were 

 seen, apparently only the main trunks and grosser threads 

 being preserved. 



Fig. 4 shows an eight-cell stage in Amphioxus, with a definite 

 abruptly curved filament passing from one cell to an opposite 

 one at the bottom of an open cleavage cavity. This is from a 

 camera sketch with oc. 2 and obj. D, not reduced. One cell 

 showed a marked elongation toward another, but no connecting 

 filaments were seen, though they may well have existed there 

 in the live state. Besides the filaments seen connecting cells, 

 as in the above figure, there were other signs of filose activity 

 in these eggs; groups of minute spherules and filaments pro- 

 truded from the ectosarc as if remnants of filose processes. 

 There were also large ectosarcal outflows near cleavage planes, 

 suggesting the amoeboid elevations described for the eggs of 

 certain nematodes by Erlanger.^ 



When more highly magnified these intercellular filaments in 

 Amphioxus appear as in Fig. 5, which represents part of another 

 eight-cell stage, drawn with camera, oc. 8 and obj. yV ini- Here 

 a filament arose from the ectosarc of one cell, and, after mak- 

 ing a complex bend, difficult to understand, gradually dwindled 

 in diameter till it became continuous with the surface of another 



'^ Biol. Ceiitrhlt. Bd. xvii. 1897 



