Embryology," from the "Bull.

Mus.Comp.

Zool." Harvard, Volume III., 1872, wrote as follows (252/2.

Part of this letter was published in "Life and Letters," III., page 154.):--) October 10th, 1872.
I am very much obliged to you for your kindness in having sent me your valuable memoir on the embryology of the extinct cephalopods.

The work must have been one of immense labour, and the results are extremely interesting.