524 Surface Geology of the Merrimack Valley. [September, 
one or more of them come in contact with the upper portion of 
the female cell they blend with it and their contents are absorbed 
and fertilization is effected. Soon a rapid growth of filaments 
and cells takes place at the base of the female organ as a result 
of this fertilization. In fact there is formed a naked cluster of 
spores (c) from these filaments, all fertilized by the single sexual 
act upon the central female cell. 
In these few pages the endeavor has only been to point out a 
few of the leading methods of asexual and sexual reproduction 
_ among fresh-water alge, and we feel in closing that the vast sub- 
ject has been but here and there touched upon. But enough has 
been said to show that eyen in these lowly forms the too often 
supposed sameness of reproduction loses itself in variety of meth- 
ods and multiplicity of changes. 
MENA E A 
SURFACE GEOLOGY OF THE MERRIMACK VALLEY. 
BY WARREN UPHAM. 
pos highest fountains of Merrimack River are Eagle Lakes, on 
Mt. Lafayette, 1090 feet below its summit and 4170 above 
the sea. The source of the straight river is a lake which lies in 
the deep Franconia Notch, beneath the jutting rocks of the Pro- 
file. This stream is at first inclosed by high mountain ranges, 
and descends more than 1200 feet in its first nine miles. Dis- 
tances and heights along this river are as follows : Profile Lake, 
about 1950 feet above the sea; mouth of East Branch, 9 miles, 
710; at Plymouth, 28 miles, 468 ; at New Hampton, 39 miles, 
438; mouth of Smith’s River, two miles below Bristol, 45 miles, 
320; mouth of Winnipiseogee River at Franklin, 55 miles, 269 ; 
mouth of Contoocook River at Fisherville, 66 miles, 249; mouth 
of Soucook River, 76 miles, 199; Amoskeag Falls at Manchester, 
89 miles, 179 to 123 ; at line between New Hampshire and Mas- 
sachusetts, 108 miles, 90; Pawtucket Falls dam, Lowell, 117 
miles, 87; Essex Company’s dam, Lawrence, 128 miles, 39. The 
entire length of this river is about 155 miles, and its last twenty 
miles are affected by the tide. 2 ; 
The Merrimack Valley in New Hampshire is comparatively 
straight, and forms a continuous line of depression which 18 @ 
principal feature in the topography of the State. Its course w 
1 This essay is principally- based upon explorations made for the Geological agi 
of New Hampshire, and will be more fully presented in vol. iii. of the report on Eae. 
survey. 
