1877.] Evolution in the Netherlands. 299 
of such a demonstration of our homage. The execution, how- 
-ever, devolved upon the directors of the “ Netherland Zodlogical 
Society,” who reasoned that, with the presentation of this unpre- 
tending mark of esteem, a few words on the history of the the- 
ory of development in the Netherlands would not be entirely un- 
acceptable, the more so, since this historic sketch clearly shows 
that, albeit some ideas in that direction had already bedn sug- 
gested here, yet to you alone reverts the honor of having formed 
by your writings a school of zealous and convinced partisans of 
the theory of development. 
Among the names in the accompanying list you will observe 
several professors of natural history, anatomy, and physiology at 
the three Dutch universities, the “ Atheneum Illustre” of Am- 
sterdam, and the Polytechnical Academy of Delft, the conserva- 
tors of the zodlogical museums, the directors of the zoélogical 
gardens, and several lecturers on zodlogy and botany at the high 
burghal schools. 
Accept, then, sir, on your sixty-ninth birthday, this testimony 
of regard and esteem, not for any value it can have for you, but 
as a proof, which we are persuaded cannot but afford you some 
satisfaction, that the seeds by you so liberally strewn have also 
fallen on fertile soil in the Netherlands. We are, sir, etc., the 
directors of the Netherlands Zodlogical Society, 
(Signed) President, A. A. VAN BEMMELEN, 
Secretary, H. T. VETH. 
The following is Mr. Darwin’s reply : — 
Down, BECKENHAM, February 12. . 
Str, — I received yesterday the magnificent present of the 
album, together with your letter. I hope that you will endeavor 
to find some means to express to the two hundred and seventeen 
distinguished observers and lovers of natural science who have 
sent me their photographs, my gratitude for their extreme kind- 
ness. I feel deeply gratified by this gift, and I do not think that 
any testimonial more honorable to me could have been imagined. 
I am well aware that my books could never have been written, 
and would not have made any impression on the publie mind, had 
not an immense amount of material been collected by a long se- 
= of admirable observers, and it is to them that honor is chiefly 
ue, 
I suppose that every worker at science occasionally feels de- 
pressed, and doubts whether what he has published has been 
worth the labor which it has cost him; but for the remaining 
