36 CORA D. REEVES. 



to learn if possible whether any relation could be found between 

 the behavior and the color characters. The work was carried on 

 under the supervision of Professor Jacob Reighard to whom I 

 am indebted for many suggestions. 



The only published account that I have been able to find of 

 the breeding habits of the darters is a brief notice by Seal (1897) 

 who observed Boleosoma olmstedi and Etheostoma ccerideum in the 

 Washington Aquarium. The rainbow darters observed by Seal 

 were probably not kept under normal conditions for spawning, 

 for in an aquarium the water is usually too deep, there is no cur- 

 rent, and the available spawning area is small. My own obser- 

 vations were made in Mallet Creek about three miles east of Ann 

 Arbor, Mich., where the stream is three to six feet across and 

 forms a succession of shallow rapids and deep pools, varying in 

 depth from two inches to two feet. 



II. Usual Appearance, Habitat, and Behavior of the Fish. 



Etheostoma cderuleum seldom exceeds two and one half inches 

 in length, including the caudal fin. Among the fish examined 

 there was little difference in the size of the two sexes, although 

 a few males of three inches were found while no female reached 

 that length. The colors of both sexes are described by Jordan 

 and Everman (1896) and other systematic writers. 



The colors of the female only slightly change with age or season 

 and are like the sand or the gravel upon which the fish rests. 

 There is on the back and sides a background of tan or olive with 

 brown or blackish patches. On the anterior part of the body these 

 are small, indefinite, and irregularly placed, but along the lateral 

 line they are closer together elongated, and obliquely directed. 

 Near the front edge of the second dorsal they merge into transverse 

 bars which are more distinct below the caudal part of the lateral 

 line. There are usually five of these. The last bar has a pro- 

 jection backward which separates two light brown spots at the 

 base of the caudal fin. The pectoral, ventral, and anal fins are 

 nearly colorless or light yellow ; the second dorsal has fine 

 dashes of brown and yellow arranged in irregular longitudinal 

 rows. The first dorsal has more distinct colors in the breeding 

 season when the outer margin is of dull grey with an irregular 



