;3r>(t The xin HI' lean Geologist. Dweini)('r, is»2 
Aveclge of till was bfiiig auuissi'd. Siil)sequ«'iilly tlu' ufcuimila- 
tion of till hi'giiu again over all the dome of sand and gravel, and 
vontinucd thenceforward until the formation of the hill was eom- 
pleted and the overlying ice disappeared. 
In addition to the evidence in the structural features of the 
drnmlins, indicating that they were accumulated rapidly during 
the closing stage of the Ghicial period, a strong argument toward 
the same conclusion is afforded by the prevailing east-southeast 
trend of the longer axes of these hills about Boston, while the 
striation on the lied-rocks is mostl}' south-southeast, the difference 
between the two courses being forty-five degrees. Recent exam- 
ination of the glacial stria? in the cit}- of Somerville. however, 
lying next northwest of Boston, shows that, besides their com- 
mon south-southeast courses, they are in many localities deflected 
to the east-southeast and even sometimes to due east. Elsewhere 
in all the districts characterized by al)undant drumlins in this 
country and the British Isles, their longer axes and the strise are 
parallel: and it seems sure that both were determined by the cur- 
rents of the ice-sheet. Their difference in direction in the neigh- 
borhood of Boston I Ijelieve to l)e due to a deflection of the mo- 
tion of the ice there during its final melting. Through the time 
of its maximum thickness and extent the ice-sheet moved south- 
southeastward across this area, and reached to the terminal mo 
raine of Long Island, Block Island. Martha's Vineyard, and Nan- 
tucket; and onward the course of its border was probabh' east- 
northeast along the submarine plateaus of the Fishing Banks. 
But when a mild climate began to cause the glacial boundary to 
recede northward, the melting proliably advanced faster upon the 
area of the gulf of Maine than upon southern New England, so 
that the ice-front became indented by a deep embayment east of 
3Iassachusetts. toward which the latest currents along the coast 
were deflected. The formation of the drumlins about Boston 
seems to have taken place wholly during the time of deflected 
glacial movements, the ground moraine being massed in these 
hills on account of inequalities in the force and direction of the 
overriding ice-sheet, when its receding l)order was probably only 
a few miles distant. Farther inland throughout Massachusetts, 
Mr. Barton finds the trends of the drumlins prevailingh' parallel 
with the striation, but with occasional exceptions where the longer 
axes of drumlins vary much from this course, probably because 
