302 



THE AMERICAN NATURALIST [Vol. XLI 



readily be forced up through the spiracles. But the larger frag- 

 ments of soft material (such as bits of sea-weed) are likely to be 

 caught on the gill-rakers, tending to clog the branchial passages, 

 and could best be dislodged and expelled by a reversal of the cur- 



The prompt, vigorous, and almost unfailing response to a touch 

 upon the cornea suggests that the fish regularly employs spouting 

 as a means of keeping the eyes unobstructed. The external 

 opening of the spiracle is so near the eye that a stream spurted 

 from the spiracle would readily wash away foreign objects which 

 settle upon the eye. 



Regarding the spiracle as one of a series of visceral clefts which 

 were primitively similar in structural relations and in function, it 

 is evident that, serving as it does such a diversity of uses, it has 

 come to differ from the more posterior visceral clefts quite as 

 markedly in its function as in its structural conditions. 



tup.ltoc;raptiy 



79 IliiMhlMi. 1>mM s 1)„ IimIh Uip/.g x\i+i2() pp , 



'99. ihf M.iMll.irv und Mandibular Breathing \alves of Telcost 

 !-i>h< s. Zool. P,ull., Vol. 2, pp. 117-124, 3 figs, in text. 



'65-70. Histoiro Naturolle dos Poissons. Paris. Tome 1, 720 pp., 



'74 On the Sk itcs (P ij r) of the 1 lutein Coast of the United utiles 

 Proc lio^tonboc .Nit IIi',t , ^ol 17, pp 170-181, 1 fig m text 

 ['Kendhtck, J. G. 



79 On the R<.piritor% Mcnemcnts of I i.he^ Joinn \n it tnd 

 Physiol., Vol. 14, pp. 461-466, pi. 28. 



