EXPERIMENTAL STUDY OF THE OYSTEB GILL 



plicae being visible to the naked eye. The neighboring filaments are connected by 

 an interfilameutal junction (int.fl.j.) formed by a band of connective tissue running 

 round the inner surface of the plicae. In every groove between the two adjacent 

 filaments there is a water pore (p.), through which the water enters into the inter- 

 filamental spaces. The two lamellae of each demibranch are, in turn, united by the 

 interlamellar junctions {int. Im. j.), having a form of septa and subdividing the 



-/mc. 

 -to. 



--A 



 l/ni J/ 



-Mv: 



A/.4li.lMV.yU' 



Fig. 1.— Cross section of the gill lamellae of the oyster. Semidiagramatic. U. p.— blood vessel; ^.—filament; /r. c— frontal 

 cilia; I. c— lateral cilia; int. hn. j,— inter lamellar Junction; int. ft. j.— inter fUamentar junction; sk. 6.— skeletal bar; 

 p.— water pores; »(.— water tubes. (SUghtly modified from Kellog) 



epibranchial chambers into canal-like compartments or "water tubes" {w. t.), vel*y 

 narrow at their distal ends but reaching several millimeters in diameter in the proxi- 

 mal portion of the gill. In an adult oyster there are about 30 tubes in each demi- 

 branch, or about 120 tubes altogether. Each filament of the gill has one blood 

 vessel (bl. v.), lined by a thin layer of connective tissue, and has two skeletal bars 

 (sic. h.). The surface of the filament is covered with a ciliated epithelium forming 

 93280—28 2 



