Bee > Mae 
the rush of new ideas excited by one after another of the 
wonders of civilisation, that she dies, like the Lady of Bur- 
leigh, overcome 
«* By the burthen of an honour unto which she was not born.” 
It is altogether a charming story, and is written in a 
style which we hope Mr. Reade will cultivate. 
In justice to the author, it must be stated that the 
present work is intended for family reading, and to popu- 
larise a knowledge of modern Africa. He promises a more 
serious book, treating of many subjects in connection 
with the native races, of great interest to students of 
man; and this will be looked forward to with interest, 
since few men are now better qualified than Mr. Reade, 
both by travel and study, to tell us the real truth about 
‘the Negro. ALFRED R. WALLACE 
LETTERS TO THE EDITOR 
[The Editor does not hold himself responsible for opinions expressed 
by his correspondents. No notice is taken of anonymous 
communications. ] : 
Tait and Tyndall 
[WE have received further communications from Professors 
Tyndall and Tait on the subject of the correspondence that has 
appeared in our columns. We feel that we are only consulting 
the true interests of Science in declining to print further com- 
munications on a subject which has assumed somewhat of a per™ 
sonal tone, and in this idea we are supported by many of the 
best friends of both parties, who, however, will approve of our 
giving the following brief extract from Dr. Tyndall’s communica- 
tion :—‘* My letter was rapidly written, and the proof of it 
reached me, not on the Tuesday evening, as I expected, but on 
the Wednesday moming when I was in the midst of my prepara- 
tions for Bradford. I had therefore little time to give it the calm 
thought which it ought to have received. On re-reading it I 
find two passages in it which I think it desirable to cancel. The 
first is that in which I speak of lowering inyself to the level of 
Prof. Tait ; the second that in which I reflect upon his manhood. 
These passages I wish to retract.” —Ed. NATURE. ] 
On the Males and Complemental Males of certain 
Cirripedes, and on Rudimentary Structures. 
I BEG permission to make a few remarks bearing on Prof. 
Wyville Thomson’s interesting account of the rudimentary males 
of Scalpellum regium, in your number of August 28th. Since I 
described in 1851, the males and complemental males of certain 
" cirripedes, I have been most anxious that some competent 
naturalist should re-examine them; more especially as a Ger- 
man, without apparently haying taken the trouble to look at 
any specimens, has spoken of my description as a fantastic 
Cream. That the males of an animal should be attached to the 
female, should be very much smaller than, and differ greatly in 
structure from her, is nothing new or strange. Nevertheless, the 
difference between the males and the kermaphrodites of Sca/- 
fellum vulgare is so great, that when I first roughly dissected the 
former, even the suspicion that they belonged to the class of 
cirripedes did not cross my mind. ~ These males are half as large 
as the head of a small pin; whereas the hermaphrodites are 
from an inch to an inch and a quarter in length. They consist 
of little more than a mere sack, containing the male reproductive 
organs, with rudiments of only four of the valves; there is no 
mouth or alimentary canal, but there exists arudimentary thorax 
with rudimentary cirri, and these apparently serve to protect the 
¢. 
NATURE 
Aa 
CN ft re a 
De ae Pe 'e 
431 
orifice of the sack from the intrusion of enemies. The males of 
Alcippe and Cryptophialus are even more rudimentary ; of the 
seventeen segments which ought to be fully developed, together 
with their appendages, only three remain, and these are imper- 
fectly developed ; the other fourteen segments are represented 
by a mere slight projection bearing the probosci-formed penis. 
This latter organ, on the other hand, is so enormously developed 
in Cryptophialus, that when fully extended it must have been. 
between eight and nine times the length of the animal! There is 
another curious point about these little males, viz., the great differ- 
ence between those belonging to the several species of the same 
genus Scalpellum: some are manifestly pedunculated citripedes, 
differing by characters which in an independent creature would 
be considered as of only generic value; whereas others do not 
offer a single character by which they can be recognised as 
cirripedes, with the exception of the cast-off prehensile, larval an- 
tennee, preserved by being buried in the natural cement at the point 
of attachment. But the fact which has interested me most is the 
existence of what I have called Complemental Males, from their 
being attached not to females, but to hermaphrodites ; the latter 
having male organs perfect, although not so largely developed 
as in ordinary cirripedes. We must] turn to the vegetable king- 
dom for anything analogous to this; for, as is well known, cer- 
tain plants present hermaphrodite and male individuals, the 
latter aiding in the cross-fertilisation of the former. The males 
and complemental males in some of the species of three out of 
the four very distinct genera in which I have described their 
occurrence, are, as already stated; extremely minute, and, as they 
cannot feed, are short-lived. They are developed like other 
cirripedes, from laryee, furnished with well-developed natatory 
legs, eyes of great size and complex prehensile antennz ; by 
these organs they are enabled to find, cling to, and ultimately 
to become cemented to the hermaphrodite or female. The male 
larvee, after casting their skins and being as fully developed 
as they ever will be, perform their masculine function, and then 
perish. At the next breeding season they are succeeded bya 
fresh crop of these annual males, In Sealpellum vulgare I 
have found as many as ten males attached to the crifice of the 
sack of a single hermaphrodite; and in Alcippe, fourteen 
males attached to a single female, 
He who admits the principle of evolution will naturally in- 
quire why and how these minute rudimentary males, and 
especially the complemental males, have been developed. It 
is of course impossible to give any definite answer, but a 
few remarks may be hazarded on this subject. In my ‘‘ Vas 
riation under Domestication,” I have given reasons for the 
belief that it is an extremely general, though apparently not 
quite universal law, that organisms occasionally intercross, and 
that great benefit is derived therefrom. I have been laboriously 
experimenting on this subject for the last six or seven years, and 
I may add, that with plants there cannot be the least doubt that 
great vigour is thus gained; and the results indicate that the 
good depends on the crossed individuals having been exposed 
to slightly different conditions of ‘life. Now as cirripedes ,are 
always attached to some object, and as they are commonly her- 
maphredites, their intercrossing appears, at first sight, impos- 
sible, except by the chance carriage of the spermatic fluid by the 
currents of the sea, like pollen by the wind; but it is not 
probable that this can often happen, as the act of impregnationt 
takes place within the well-enclosed sack. As, however, these 
animals possess a probosci-formed penis capable of great elonga- 
tion, two closely attached hermaphrodites could reciprocally 
fertilise each other This, as I have elsewhere proved, does some- 
times, perhaps often, actually occur. Hence perhaps it arises, that 
most cirripedes are attached in clusters. The curious Anelasma, 
which lives buried in the skin of sharks in the northern seas, is 
said always to live in pairs, } Whilst reflecting how far cirripedes 
