NATURAL HISTORY OF AMIA CALVA LINNAEUS. 73 



ably, like many teleosts, he then sweeps the underlying rootlets clean of bottom 

 ooze by the fanning movements of his pectoral and caudal fins. Where he excavates 

 into sand or gravel the work is probably done largely, as in teleosts, by fanning with 

 the caudal and paired fins. This much may be inferred from the fragmentary obser- 

 vations here recorded. 



F. LOCATION. The nests are located in the most diverse places. Often 

 they are in the midst of bushes or beneath overhanging branches; again under 

 fallen tree-trunks, beneath the horizontally projecting roots of stumps, or at the 

 sides of logs or stumps. In such cases they are often difficult to find and would 

 almost certainly be overlooked by one not experienced in such matters. Again, 

 and not infrequently, they are located in quite open water. In such cases a round 

 patch of the bottom is thoroughly cleaned, leaving the brown fibrous roots exposed. 

 Nests of this sort, when freshly filled with the yellow-white eggs, are most conspic- 

 uous and readily seen, even by the inexperienced, at a distance of six metres or 

 more. In general, where nests are sheltered, they are so placed as to be protected 

 from above and on one side, and at the same time so that the fish has free access 

 to deep water on the opposite side. But even nests built in open water may be 

 wholly concealed by last year's floating vegetation, especially by the floating leaves 

 of cattails. Nests thus concealed may, when fresh, be detected by the cuttings 

 over them or searched for by parting here and there the mantle of cattails and 

 peering beneath. In the season of 1899 I found very few nests during the early part 

 of the season, and was about to give up the search when I discovered that nearly all the 

 nests were concealed under floating cattails. The next year I had all this removed 

 with a rake before the season opened. 



The conspicuousness of the nest depends not merely on the openness of the 

 water in which it is, but upon the extent to which the aquatic plants have grown 

 up and upon the number of eggs in the nest. If the aquatic plants are well grown 

 when the nest is made, the nest forms a conspicuous round hole in the midst of them. 

 If there is only a low growth of aquatics when the nest is made, it is correspondingly 

 less conspicuous. Nests with only twenty-five or fifty eggs are of course much less 

 easily seen than those lined with several thousand. The conspicuousness of the 

 nests rapidly decreases as the eggs in their development become darker and as the 

 newly cleaned, light-brown rootlets of the nest bottom darken through exposure 

 to the light. That Whitman and Eycleshymer ('97) found the nests inconspicuous, 

 while Dean ('96, '98 a ) found them at times conspicuous, is probably due to the location, 

 character, and age of the nests seen by these investigators, as well as to the differ- 

 ence in the color of eggs and nest bottom in different localities. 



