2 G. H. PARKER 



Suspended carmine is not carried into them or discharged from 

 them; in other words, there is no evidence of a ciliary current pas- 

 sing through the olfactory sacs such as is so easily demonstrated 

 in the catfish. If a head in which the respiratory movements of 

 the gills are still in progress is examined, well marked currents 

 can be demonstrated in the olfactor}^ organs. Suspended carmine 

 is taken in at the anterior aperture and discharged from the pos- 

 terior one. With each respiratory movement, the valve in the pos- 

 terior aperture opens, a small amount of water is discharged, and 

 it then closes. This passage of water through the olfactory ap- 

 paratus is apparently due to the changes of pressure produced by 

 the rythmic activity of the muscles of the gills probably acting 

 in conjunction with valves within the olfactory sacs. The move- 

 ment of the valve at the posterior aperture follows exactly that 

 of the respiratory apparatus and its automatic character is obvious 

 from the fact that if an anterior aperture in an active fish is closed 

 by having its walls stitched together so that no current of water 

 can enter the sac at that point, the posterior valve of the same side 

 ceases to pulse, though that of the other side continues in normal 

 activity. If, now, the closed aperture is reopened by removing 

 the stitches, the valve previously quiescent begins again to pulse. 

 Thus, though Fundulus has no continuous current through its 

 olfactory sacs, such as the catfish has, it does have a well-developed 

 intermittent current that is not inappropriately designated as res- 

 piratory, though this current is in no direct way concerned with 

 the respiratory function. Apparently, as long as the gill muscles 

 of Fundulus carry out respiratory movements, currents of water 

 run through the olfactory sacs. 



As a preliminary test to ascertain whether Fundulus could 

 discover hidden food or not, packets of cotton cloth containing 

 dogfish meat wrapped so as not to be visible, and packets made 

 of nothing but cotton cloth were hung in an aquarium in which 

 there were a number of hungry Fundulus. After the packets had 

 been thoroughly soaked in the seawater, the reactions of the 

 •fishes to them were watched. The packets without meat were 

 occasionally approached and siezed, but soon dropped. Those 

 that contained meat were sooner or later surrounded by most of 



