1877. ] Evolution in the Netherlands. 297 
Harmonie van het. dierlijk leven, de Openbaring van Wetten ” 
(The Harmony of Animal Life, the Revelation of Laws), expressed 
his opinion that in the gradual change of form consequent upon 
change of circumstances, may lie the cause of the origin of differ- 
ences which we are now wont to designate as specific. The lat- 
ter, in the winter of 1856, delivered a series of lectures, before a 
mixed audience, on The History of Creation, which he published 
the following year under the title of ‘* Voorwereldlijke Scheppin- 
gen” (Antemundane Creations), with a diffuse supplement de- 
voted to a critical consideration of the theory of development. 
Though herein he came to a stand-still with a “ non liquet,” yet 
it cannot be denied that there gleamed through it his preposses- 
sion in favor of a theory which several years later his famed and - 
learned colleague, J. van der Hoeven, professor at Leyden, mak- 
ing a well-known French writer’s words his own, was accustomed 
to signalize as an explanation, “ De l’inconnu par l’impossible.” 
In 1858 your illustrious countryman, Sir Charles Lyell, was 
staying for a few days in Utrecht. In the course of conversa- 
tions with this distinguished savant on the theory of develop- 
ment, for which Lyell himself, at least in his writings, had shown 
himself no pleader, the learned of this country were first made 
observant of what had been and what was being done in that di- 
rection in England. He attracted attention to the treatise of 
Wallace in the Journal of the Linnean Society, and related how 
his friend Darwin had been occupied for years in an earnest 
study of this subject, and that ere long a work would appear 
from his pen, which, in his opinion, would make a considerable 
impression. From these conversations it was evident that Lyell 
himself was wavering. In the following edition of his Principles 
of Geology, he declared himself, as we know, a partisan of the 
hypothesis of development, and Professor Harting speedily fol- 
lowed in the same track. In his “ Algemeene Dierkunde ” (Gen- 
eral Zodlogy), published in 1862, he was able to declare himself 
_With full conviction a partisan of this hypothesis. Also another 
famous savant, Miquel, professor of botany at Utrecht, who had 
previously declared himself an opponent of the theory of devel- 
opment, became a convert to it in his later years, for although 
this is not expressed in his published writings, it was clearly 
manifest in his private conversation and in his lectures. To what 
must this conversion be attributed? With Harting and Miquel, 
as well as with Lyell and so many others in every country of Eu- 
rope, this was the fruit produced by the study of your Origin of 
