Editorial Comment. 2s\ 
tions, photographs, models, ripple marks experimentally made, 
and theses. The natural advantages of Cambridge as a geo- 
logical center were shown by a map of the vicinity of Boston. 
with numbered localities explained by a descriptive list, and 
illustrated by photographs. Among the subjects shown were 
sea-shore features, such as cliffs in hard rock and in glacial 
deposits, beaches of different kinds, sea-shore chasms, wave- 
built spit and wave-cut beach above the present shore level. 
and tidal marshes with meandering streams: noteworthy 
among the glacial subjects were a cross section of an esker, 
cuttings showing contorted gravels and faulted sands, and 
roche moutonee forms: of the bedded rock views those show- 
ing numerous complex relations between sedimentary and 
metamorphic rocks and igneous intrusives of different kinds, 
as well as between the intrusives themselves, were of greatest 
interest, for in one view could lie seen granite including di- 
orite breccia cur by a diabase dike which has been much 
raulted. 
The naturaj adjuncts of the general geological course were 
represented in a similar manner. To illustrate the element- 
ary course in physical geography were shown selected maps 
of land and sea areas and sets of paper models with explana- 
tory cards. It was noteworthy that some of the foreign maps 
here shown as parts of the laboratory equipment were also 
shown among the foreign .exhibits as samples of line work. 
One set of models selected showed the development of river 
drainage. Tin- first conditions represented were of a land 
mass well elevated, the main streams flowing along valley- 
having narrow bottoms and with rather steep sides: the side 
streams, beginning in but few branches on the upland, had cut 
no considerable valleys : the stage of development is that of 
youth. A second model indicated the result of further growth 
headwards of the various streams. The main stream valleys 
have been filled with sediments, and the streams have begun 
to meander on their rloodplains : the side stream- have difS 
culty in reaching the main stream, some wander considerable 
distances down the floodplain before getting into the master 
stream, some have been lakes, and into the lakes are growing 
deltas fed by the little branches. The whole is typical of ad- 
olescence. The stage of maturity was manifest in the iievi 
