CORRESPONDENCE. 
EXPERIMENTAL EVOLUTION. 
In the last number or NATURAL SCIENCE, P, C. M. delivers some criticism o 
my lectures on Experimental Evolution. He is quite right in criticising me when he 
says that ‘‘ While royal food may ripen the latent sex of a worker (re bees) a dif- 
ferent factor has to do with the distinction between male and female.’”’ I should 
have said that sexuality, i.e., the development of sex, or the possession of sex, may be 
determined by food; sev is not determined thus, as while unfertilised eggs develop 
only into drones, fertilised eggs, according to circumstances—and food—develop 
into queens oy workers. 
But when P. C M. says, concerning the statement that ‘‘ we possess in the facts 
of domestication and inheritance a large number of cases of variation, which occurs 
in every part, due to environment, and transmitted in various degrees,”’ that ‘‘ if the 
statement were true there would be no controversy,” this is a rather sweeping 
criticism. There are five distinct propositions in this statement. Does P. C. M. 
object to all, cr only to part of them? Does he deny variation due to cultivation 
and domestication? does he deny the occurrence of variation in every part of 
organisms? does he deny only the fact that variation is due to environment? or does 
he object to its hereditary transmission? I grant that, in ascribing variation to 
environment only, I would be saying more than I am prepared to assert, as, in fact, 
the cause or causes of variation are unknown; but environment in its broad sense 
seems to have something to do with variation, as many facts go toshow. P.C. M. 
may certainly object to part of my statement, but it would be fair, if only towards 
his readers, 1f he stated which part he considers as most heretical. 
The same critic informs me that Professor Le Conte’s classification of the 
factors of evolution is ‘‘curiously inept,’’ and charges me with approval thereof, 
which surely cannot improve my situation. However, I must decidedly object toa 
method (?) of criticism (??) which consists in quoting part of a statement and 
leaving out the remainder. I have merely given Le Conte’s list of ‘‘what the 
factors of evolution are, or are supposed to be”’ (p. 229: there is not much approval 
in this), and if P. C. M. had taken the trouble to go on with the quotation, and to 
quote what I say of this list (which, in fact, is a mere enumeration of the principal 
factors of evolution proposed on different sides, a mere catalogue), he would have 
seen that I state that ‘‘ the five factors are not all recognised by the same group of 
evolutionists,”’ the two first being especially Lamarckian, and that, in my opinion, no 
definite view concerning the real value of these different factors can be entertained 
as long as all have not been subjected to the test of experiment. 
If I have ‘‘approved”’ of the list, Ido not see that I can be considered as 
having approved of the scientific soundness of the views expressed in it, inasmuch 
as no one does adhere simultaneously to each of the five views expressed, and I 
should be the last todo so, since I ask for proofs of each and ail. 
P. C. M. ends with a very virtuous and mighty sentence, which, abridged, might 
be of high moral use in a copy-book ; but I fail to see how it applies to myself. I 
have not the slightest wish to confound anybody, nor am I familiar with the devices 
of political controversy—which, I perceive, are exceedingly wicked—and while 
advocating, from the first to the last page, the necessity of submitting theories to 
the test of experiment, in order to ascertain the exact situation of that swift-footed 
fugitive, truth, I certainly did not expect to be charged with resorting to methods 
which are not only unscientific, but, strictly speaking, unfair. 
Paris, November, 1892. HENRY DE VARIGNY. 
