44 MKMOIRS OF THE NUTTALL ORNITIIOLOCJICAL CLUR 



with earth taken from the meadow on the opposite side of the road when the ice- 

 pond known as the Glacialis was dug by the Tudors about 1S50. It was not 

 brought to its present smooth and level grade, however, until the Cambridge 

 Water Board took it in hand in 1884. Up to this time it remained, as Mr. Cabot 

 described it in 1869, a "bit of mangy pasture" where cows and goats were 

 tethered. The made land, easily distinguishal)le by its rough, hilJocky surface 

 and sufficiently elevated to be reasonably dry at all seasons, was separated from 

 the still higher and firmer ground at the eastern extremity of the Tudor estate 

 by a rather wide belt of wet and perfectly primitive marsh. This, evidently, 

 had once formed the western shores of the cove, and there were similar rem- 

 nants of a narrower strip of marshy land which had formerly intervened between 

 its northern shores and the Concord Turnpike. 



When the turnpike was built it crossed Alewife Brook only a few yards 

 below the outlet of the pond by means of a wooden bridge. The filling of the 

 cove resulted, of course, in the removal of the outlet to the new shore line, 

 about two hundred yards to the southward of the road. For more than twenty 

 years after this, however, the brook continued to flow directly out of the pond, 

 traversing the made land by an open but narrow ditch, antl ])assing under 

 Concord Avenue through a stone culvert. Just beyond this culvert the original 

 channel,^ broad, sinuous and overhung by large trees, skirted the western edge 

 of the Maple Swamp, but the brook filled it only at high stages of water, being 

 ordinarily confined to a straight, artificial trench which ran parallel to, and about 

 forty yards from, the eastern shore of the Glacialis. To the northward of the 

 Fitchburg Railroad embankment its course had also been narrowed and straight- 

 ened to the point where it united with Little River. Although no longer the 

 primitive and generous stream so charmingly described by Mr. Cabot, it still pos- 

 sessed a few reaches of great attractiveness, and carried, at least in early spring, 

 a considerable volume of sweet, undefiled water. Through it the migratory fish 

 from which it takes its name still passed and repassed on their way to and from 

 the sea. In April and May, when they were running up the brook, very many 

 of them were caught by the Irish (who had then only recently settled in the 

 neighlioihood) with dip nets or in rude weirs, and I have seen two or three hun- 

 dred taken at a single cast of a small seine. They spawned in F"resh Pond, 

 where their fry literally swarmed in autumn, attracting numbers of fish eating 

 birds and supplying abundant food for the numerous pickerel and other preda- 

 tory fishes. 



Whenever there was a course of exceptionally high tides the normally 

 sluggish but steady flow of the brook towards the sea was replaced by a rather 



' This channel may still be traced distinctly in several places. 



