384 
NATURE 
[ August 26, 1886 
test against Herbert Spencer’s application of the principles 
of evolution to the solution of vital, social, and mental 
problems. The author then proceeds to set up a ghost 
founded on the statement made some years ago, that 
“there is no evolution without spontaneous generation.” 
To refute the theory of spontaneous generation will be, 
he says, to give a direct blow to the theory of evolution. 
This, he maintains, has been amply done by Pasteur and 
others, and a number of the most important experiments 
are here referred to. 
The author proceeds to argue that, since evolution has 
failed to explain the first beginnings of life, there must 
have been a God who created matter, a living germ, and 
an intelligent mind, and that the three creations were 
distinct. 
He gives a clear account of many of the vital as 
distinct from the non-vital processes, and draws especial 
attention to the fact that solutions of many of the 
higher organised products polarise light, and that the 
only organic bodies which have been formed synthetically 
are the lower organised products which do not polarise 
light. It is doubtful, however, whether the distinction 
is one which will hold much longer, as chemical methods 
are constantly improving. 
The author adduces no new facts, but he has the merit 
of bringing together in a very readable form, statements 
more or less scattered about in several books and 
periodicals. 
History of the Royal College of Surgeons in Ireland, 
By Sir Chas. A. Cameron. (Dublin: Fannin 
and Co., 1886.) 
THIs volume, which is published at the expense and by 
the authority of the College of Surgeons, collects to- 
gether the charters and histories of the various Irish 
Medical Schools and Colleges, and supplies biographies 
of the leading members of the medical profession in Ire- 
land, together with a list of their works. 
Many curious ana are given of the old physicians ; 
among others, of Joseph Rogers (1734), one of the first to 
Gis 
oe. 
feed fevers, who gave a patient daily for a month four to | 
six quarts of sack-whey and two quarts of mulled canary, 
which was certainly vigorous treatment. 
The first Society for the regulation of medicine in Ireland 
dates back to 1446, when Henry VI. established a Guild 
of Barbers in Dublin; and later on, in 1572, Queen 
Elizabeth granted a new charter by which women were 
admissible to the guild; and in those days a barber 
was equivalent to our surgeon. This Society lingered on 
until the foundation of the College of Surgeons in 1784. 
This book will be of great use as a work of reference | 
with regard to the state of medicine at any period in Ire- 
land, and its compilation must have been a_ laborious 
labour of love on the part of the author. The biographies, 
which are very numerous, form the most interesting part 
of the work, and include a large number of world- 
renowned names, the greatest of which are probably 
Graves and Stokes. 
LETTERS TO THE EDITOR 
{The Editor does not hold himself responsible for opinions ex- 
pressed by his correspondents. Neither can he undertake to 
return, or to correspond with the writers of, rejected manu- 
scripts. No notice is taken of anonymous communications. 
[The Editor urgently requests correspondents to keep their letters 
as short as possible. The pressure on his space ts so great 
that it is impossible otherwise to insure the appearance even 
of communications containing interesting and novel facts.] 
Physiological Selection and the Origin of Species 
As I was unable to be present at the Linnean Society when 
Mr. Romanes read his paper on the above subject, I may take 
‘he opportunity furnished by the publication of the abstract in 
these columns to put forward certain views which I have long 
held with reference to the points raised by the author. I may 
remark that I am writing under the disadvantage of distance 
from notes or books of reference, and that I have not yet seen 
the complete paper. Moreover, my work of late years has run 
off biological tracks, and I can but regret that my remarks must, 
under the present circumstances, be of a more or less general 
character ; but at any rate they may be of use as a contribution 
to the discussion which Mr. Romanes’ carefully considered 
paper well merits at the hands of biologists. 
In the first place, I should like to point out that evolution by 
what Mr. Romanes calls ‘‘independent variation,” or the pre- 
vention of crossing with parent forms, is very ably discussed by 
Weismann in one of his earlier works, ‘‘ Ueber den Einfluss 
der Isolirung auf der Artbildung” (1872), which essay I can 
commend to the notice of all interested in the subject. Weis- 
mann termed this principle ‘‘ Amzzxie,” and for want of a better 
word I have rendered this ‘‘Amixia” in my edition of the 
“* Studies in the Theory of Descent,” in which work the prin- 
ciple is also frequently alluded to. 
All evolutionists will agree with Mr. Romanes that natural 
selection Zev se is incompetent to account for the origin of species. 
This has long been admitted by naturalists, and Darwin himself 
in later life frankly acknowledged that in the early editions of 
the ‘‘ Origin of Species” he over-estimated the power of this 
agency. Nevertheless, Darwin to the last considered natural 
selection as the chief agency in the evolution of species, and no 
one saw more clearly than he did the difficulties which sur- 
rounded the formation of incipient species, owing to the ob- 
literation of new characters by intercrossing with the parent 
form. The sterility of natural species as compared with the 
fertility of domesticated races is also a difficulty which Darwin 
fully recognised and did much towards meeting. The results of 
his investigations in this direction have been to break down the 
supposed fixity of the rule, although it must be admitted that 
the broad fact still remains, and we cannot but be grateful to 
Mr. Romanes for once more emphasising this difficulty with his 
characteristic clearness. It is chiefly—if not entirely—with the 
object of meeting this difficulty that ‘ physiological selection” 
has been conceived, because, as it appears to me, the other diffi- 
culties referred to by Mr. Romanes, viz. those connected with 
the prevention of intercrossing and the inutility of trivial charac- 
ters, are quite subordinate to this main difficulty, and need not 
be further considered until the admissibility (or otherwise) of 
physiological selection has been settled. The questions now to 
be decided are whether natural selection + sexual selection + 
correlated variability + amixia + use and disuse, &c., is really 
a theory of the origin of sfecées, or whether these factors have 
been only made to ‘‘ pose” as such? Is ‘‘ physiological selec- 
tion ” competent to account for the origin of species ? 
If I interpret Mr. Romanes correctly, his theory is equivalent 
to the admission that amixia may become inter-racial, z.e. that it 
may arise among the individuals of a species without the inter- 
vention of physical barriers by the spontaneous origination of 
a physiological barrier, ze. by variation in the reproductive 
capacity. That such a form of variation may exist I have long 
been willing to admit, and I do so now with all the more readi- 
ness in face of the arguments so skilfully marshalled by the 
author of the new theory. But, since Mr. Romanes admits the 
efficiency of natural selection, the question séems to resolve 
itself into this: Can physiological selection work independently 
of natural selection? If not, natural selection must still be 
regarded as a prime factor, and if physiological selection cannot 
originate a species independently of the control of natural selec- 
| tion, surely the latter, with its subordinate factors (of which 
physiological selection say de one), is still ¢he chief element in 
the theory of the origin of species. 
Let us suppose, for the sake of argument, that among the 
individuals of a species there arise certain varieties which are 
fertile zfer se, but sterile with the parent form. There would 
thus arise a new race which could not be swamped by inter- 
crossing with the predominant form, and the one species would 
practically be resolved into two—the parent form being still in 
the ascendency as regards numbers. But the competition is 
always most severe between the most closely related forms, and 
unless the new form (arising by inter-racial aimixia) possessed 
some distinct advantage over the old one, it would as surely be 
exterminated by the overwhelming majority of the parent type 
as it would be by intercrossing in the absence of amixia. Physio- 
logical selection thus appears to me to be as subordinate to 
