ECOLOGICAL SUCCESSION. 



lit where the study was first begun, before the draining took 

 place. 



Had Pond 140 not been disturbed by man, it would have 

 ontinued to fill with humus. Its center would have o>me to be 

 occupied by the cat tail-, bulrushes, Proserpinaca, and Equisetum, 



all of which invade trom the sides. \Yhen -ueh a Mage wa- reached 

 ii \\oiild le >ubject i.. almost complete drying in extreme droughts 



and the li-h \\oiild be eliminated in the order of their ability 

 10 \\ith-tand draught, and in relation to accidents of distribution 

 in part> of t : 1 drving t<. various 



In ^cpicinber. Ioo>. \\ able to obtain e\ ideiice on this 



point from some of the older pond-. A u'iip of black bullhead-, 



! and mud minnow- were found in the lowest part 



ne of th, ms of p..nd 5*. The pickerel Were dead and 



badl\ ed. The bill! land jll-l bcgiimilK 



but ihe mudmimio\\-. fully a 1-u-hcl of them, were -till 

 ali\e ahliough \\ithoul v I hi- lot included -mne of the 



large-t indi\ idlial- o.|i< 



\\'h : I ' -nd I ) -h content Would 



becom( probl. : ent upon the distribution of 



the dilten-iH .;iid shalloue;- parl- 



o| the |)ond. and tin - relat* d lo the 



the d: I \ j.lence for this i- seen in 



Polid I j . v i- the onl\ -111 



since a pmbabli 1 df\ili^ of the |)ond. 



Indeed. Ue II I he |iredictio|| one -tep farther. \Yllell 



-in h a pond become- of tin- -or! the plant- that take hold of 

 it are i \*< \\ liich till the -oil \\ iih ro. 



and form hummock-. I: i'ole to them, -uch pond- be- 



rome the breeding place of tl ii-h. During the drought i 



i MO- I found a -chool .f half ^ro\\ n dog li-h in -uch a pond, which 

 an-\\ered the description of the la\oHtc breeding place of the 

 do^ ti-h ,. a 1>\ Kei^hard [*O2 , >uch - thi- \\ill 



be folloued b\- the inv.i-ioii of -hrub> and ilu- final de-tructioii 

 of the pond a- an aquatic habitat. 



\\ e ha\e in |ioiid- a p- : \> change in the <-onditioii- and 



a p- jive change in the co-logical and |)h\>i< -logical character 



of the ti-h comimmitie-. and a succession or evolution of fi^h 



