134 VICTOR E. SHI I.I i >kl>. 



the distribution of tin- chub Mickt r in Pond- ~a and ~'< \^ \ ntircly 

 similar to the distribution of the perch in Ponds 50 and 6 and 5 . 



The chub sucker is not in tin- part of tin- Ion- Pond 7 which li. - 

 been recently connect. -d with tin- outlet. 



It will be noted al>o that tin.- tadpole cat and the -potted bull 

 head have not been taken in 5</. The yellow bullhead ha-dum 

 taken from ~a but once, but we may expect that ii i- a re-id, nt 

 of the locality. One would expect to tind it in Ponds 56 and 5c. 



With the exci ption of Pond- 14(1 and 14/1. there arc- no non-- 

 worthy peculiarities. The study was begun in 1411. Thi- was 

 partially drained in the winter of i<n>X <> and it was therefore 

 necessary to turn attention to i _}./;. This was probably partially 

 drained previous to i8<>2 by the East Chicago shin canal, but 

 again renewed through a dam made by the building of tin- YVaba-h 

 railroad grade between the point of draining and the part 

 pond studied about 1892. This probably accounts for the pres- 

 ence of only a single species in Pond 14/7. A single juvenile !>' 

 spotted sunfish was found in Pond 56 which is directly conm-cu d 

 with the Calumet River where it is common. 



2. Ecological Age of Ponds. The ecological age of the pond:* 

 is determined by an inspection of (a) the amount of bare bot torn. 

 (b) the amount and kind of vegetation, and (r) the amount of 

 humus. It is a well-established fact that an entirely new pond 

 (in the matter of recent separation from a lake, like Lake Michi- 

 gan) has little vegetation and very little or no humus. Both 

 vegetation and humus come only with ag< . Ag< -determination 

 is so simple that no difficulty usually is experienced by 

 trained in plant ecology, in arranging a l pond-, in the 



order of their ecological age. In the mailer of the kind of 

 vegetation we have had the advice of Dr. II. ('. ("owl 



Pond i is the youngest, because it has the- kind of vegetation 

 that grows in young ponds, more bai I bottom, h ,.-i humu>, 



and least vegetation. For similar n I'on-i- ->' and ,v -land 



second in the matter of age. Because of lnini.ui interfi rence, 

 which has kept the vegetation down in I'ond % v, ii i^ probabh- 

 ecologically >'ounger than 5/7. The oui! orobabK- inter- 



mediate between 5 aiul 7. Pond '..ml next, but with- 



out anv dilTei'ence as far as on< 



