VICTOR E. SHELFORD. 



M.ip II. shows the relations of the fii>t t\\enty-four of tlu>e ponds. 

 The recent changes of this smaller area are indicated <>n this map 

 by the dates of the building of the various road and railroad 

 grades. 



III. THE DATA. 



All methods <>t collecting have been employed. The dip net 

 has been found most elTecthe, but the drought of 1908 and drain- 

 ing b> sewers have yielded cruical results in Ponds i , the outlet . 

 Pond 5</, .v , i-|</ .ind ~h. 



\\'ith tin- exception of Anna caha, tin- records are for adults, 

 or for young where the pond is known to be isolated, and the 

 presence of adults is therefore necessarily implied. 



The record of Ameiurns melas in Pond 56 is based upon the 

 presence of young and adults; identification of the adults 

 depended upon identification of the young, because the adults 

 \\ere too badly macerated to make identification practicable. 



i. nistrihntion of the Species of Fish. The distribution of the 

 fish in the various isolated parts of the ponds is of much impor- 

 tance. Turning to Map II., we note that the extension of the 

 ponds to the east and west is not shown. Toward the east Ponds 

 i to 17 become shallow near the Gary Steel Plant and are not- 

 connected with other bodies of water. Parts of Ponds I to 7 

 have been directly connected with the lake by the outlet (Map 

 II.) until within the past few years. Excepting in the case of 

 pond 7, other connections with the lake, to the nort Invest of the 

 area shown on our map, have probably been closed for a much 

 longer period. \Ye may concern ourselves largely with the 

 parts of the ponds to the east of the outlet, \\hich have been 

 isolated by railroad grades, and with their relation to the outlet. 



Table I., taken with Map II., presents the exact data on the 

 distribution of the fish in the various parts of the ponds. All 

 fish nomenclature is after Forbes and Richardson, '08. 



In Table I. we note first that the large-mouthed black bass, 

 the suntishrx. the pumpkin seed, and tin- warmouth, are all con- 

 fined to the outermost pond, or Pond I. The pa^a.^e Irom pond 

 l to the outlet and to pond 5 was open until 1906. The study 

 began in 1907. In the autumn of n ( oS the drought reduced the 

 water in the outlet to a minimum, but none of the-r -pecie> \\a> 



