604 J. E. DUERDEN. 
would be slowly drawn down the stomodzeum, instead of being 
driven away. ‘This movement, however, was never carried 
out with the same readiness as described below for nutritive 
substances, and in some instances the indrawal would cease 
altogether, and after a short interval the shreds be rejected 
and wafted away over the disc. 
When a clear solution of meat extract is poured over a 
colony of Favia, with the polyps fully expanded, the 
following reactions take place :—(1) The tentacles twist and 
turn mouthwards, and the individual polyps partly retract ; (2) 
the polyps recover and the tentacles are fully extended out- 
wards; (3) while 1 and 2 are in progress the mouth of each 
polyp opens very widely, the peristome protrudes somewhat, 
Fic. 5.—Nutritive particles dropped upon a colony of Favia and 
flowing in a mucous stream down tle stomodeum. 
and several streams of mucus are seen passing down the 
stomodeeum (figs. 5, 6); (4) after the ingestion of the mucous 
streams the mouth closes and the polyps recover their normal 
condition. 
If the nutritive solution be rendered conspicuous by mixture 
with finely powdered carmine or sepia, the polypal reactions 
are the same as with the extract alone. The particles of 
carmine or sepia fall in a uniform manner over the surface of 
the disc and tentacles, and later are arranged in mucous 
streams. The streams are seen to form first upon the peri- 
stome, and then to extend over the entire discal and tentacular 
areas. Moreover, towards the close of the indrawal, the 
streams entering the mouth of any one polyp are found to be 
continuous in a radiating manner with those entering the 
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