Letters of Asa Gray, edited by Jane Loring Gray ... .

2

The life and letters of Charles Darwin, including an autobiographical chapter. Edited by his son, Francis Darwin.

2

Letters of Asa Gray, edited by Jane Loring Gray ... .

1

More letters of Charles Darwin. A record of his work in a series of hitherto unpublished letters, ed. by Francis Darwin ... and A.C. Seward ...

2

Emma Darwin, a century of family letters, 1792-1896, ed. by her daughter Henrietta Litchfield ...

2

More letters of Charles Darwin. A record of his work in a series of hitherto unpublished letters, ed. by Francis Darwin ... and A.C. Seward ...

1

Emma Darwin, a century of family letters, 1792-1896, ed. by her daughter Henrietta Litchfield ...

1

The life and letters of Charles Darwin, including an autobiographical chapter, ed. by his son Francis Darwin ...

2

Life, letters, and works of Louis Agassiz, by Jules Marcou.

1

Life, letters, and works of Louis Agassiz, by Jules Marcou.

2

The life and letters of Charles Darwin, including an autobiographical chapter. Edited by his son, Francis Darwin.

3