Charles Darwin an Ernst Haeckel, Down, 15. Juli 1879
DOWN, | BECKENHAM, KENT. | (RAILWAY STATION | ORPINGTON. S. E. R.)
July 15. 1879
My dear Häckel
On August 1st we all go for a month to the Lakes in Cumberland, as I want a little rest. I your return home is delayed till September & you can possibly spare the time, I hope that you will pay us a visit, as it would || be a great pleasure to me to see you.
I am astonished to hear what a gigantic undertaking the description of the Radiolarians collected during the Challenger expedition proves to be.
I am glad to hear || that your labours on the Medusa are drawing to close.
For Heaven sake do not overwork your brain, & always remember what e tender organ it is.
My dear Häckel
Yours truly sincerely
Charles Darwin