It can be a little difficult to keep track of Croll's papers on climate change spread out over the years from 1864 to 1867 in Philosophical Magazine. A list might prove useful.
Aug 1864, p. 121, On the Physical Cause of the Change of Climate during Geological Epochs
Jan 1866, p. 26, On the Excentricity of the Earth's Orbit
Apr 1866, p. 301, On the Physical Cause of the Submergence and Emergence of the Land during the Glacial Epoch
Feb 1867, p. 119, On the Excentricity of the Earth's Orbit, and its Physical Relations to the Glacial Epoch
Jun 1867, p. 426, On the Change in the Obliquity of the Ecliptic, its Influence on the Climate of the Polar Regions and on the Level of the Sea
These papers can be found elsewhere and much of the content is reproduced in Croll's first book.