From Hermann Otto   15 June 1879

Sir,

My joy at the beautiful present of

“The Descent of Man”

and my zeal for penetrating in it are so great that I almost had forgotten there-at to thank my benevolent author;¹ you will therefore kindly excuse my negligence and not take off me your high favour by which I am so inexpressibly happy.

With glad heart I thank you for your exceeding kindness to which I shall also show myself thankful and worthy for my all life.

I remain, Sir, | in all duty | your most obedient servant | Hermann Otto, stud. rer. nat.