REACTIONS OF FISHES TO ATMOSPHERIC GASES 219 



Gas escapes in bubbles through the tee and bubbles are not 

 introduced into the apparatus, where they interfere with the 

 experiment. 



III. MATERIAL 



The material used in these experiments consisted of the fol- 

 lowing: Young of the common sucker (Catostomus^ commersonii 

 Lac, 8-11 cm. long, adult length 45 cm.); adults and young of 

 the golden shiner (Abramis crysoleucas Mit., 6-15 cm. long., 

 adult length 15-20 cm.) ; a few adults and many young of the 

 common shiner (Notropis cornutus Mit., 5-9 cm. long, adult 

 length 12-20 cm.); young of the river chub (Hj^bopsis kentuck- 

 iensis Raf., 7-10 cm. long, adult length 15-20 cm.); young of 

 the black bull-head (Ameiurus melas Raf., 13-15 cm. long, adult 

 length 30 cm. of more) ; adults of the mud minnow (Umbra limi 

 Kirt., adult length 10-13 cm.); young of the rock bass (Amblo- 

 phtes rupestris Raf., 4-10 cm. long, adult length 20-35 cm.) ; 

 young and adults of the blue spotted sunfish (Lepomis cyanellus 

 Raf., 4-6 cm. long, adult length 10-18 cm.) ; young of the small- 

 mouthed black bass (Micropterus dolomieu Lac, 8-9 cm. long, 

 adult length 30-38 cm.); and adults of the rainbow darter (Ethe- 

 ostoma coeruleum Stor., adult length 5 cm.). The stock also 

 included one or two adults of Ameiurus nebulosis LeSur., 

 Schilbeodes exiUs Nel., Boleosoma nigrum Raf., Hadropterus 

 aspro C. and J., and one or two young of Campostoma anomalum 

 Raf. and Notropis atherinoides Raf. On some occasions noted 

 in the text, one or two of these were included in experiments 

 with other closely related species. Others were used for pre- 

 liminary' experiments which are barely mentioned. 



1. STOCK OF FISH 



The Ambloplites, Hybopsis, Micropterus, Notropis, Ethe- 

 ostoma and Schilbeodes used in these experiments, were collected 

 from Hickory Creek, New Lennox, Illinois, October 30, 1911. 

 The Boleosoma, Lepomis, and Catostomus were taken at Floos- 

 moor, Illinois, from Butterfield Creek, November 13. One or 



- In the body of the paper the fishes are sometimes referred to by the generic 

 names only, when it is to be understood that the species listed above are meant. 



