Fan. 18, 1883] 
NATURE 
279 
(126 x 420) about 53,000 times that of a candle-flame. This is 
more than three times the value found by Arago for the intensity 
‘of the light from the sun’s disc as compared with that from a 
candle-flame ; so much for a Gla‘gow December sun! 
The ‘og cm. diameter of the pin-hole, of the Glasgow obser- 
vation, subtends, at 230 centimetres distance, an angle of 1/2556 
of a radian; which is 23°7 times the sun’s diameter (1/108 of a 
radian). But at 230 cm. distance the sunlight through the pin- 
hole amounted to 126 times the York moonlight (which was I 
candle at 230 cm. distance). Hence the Glasgow sunlight was 
[(23°7)? x 126 times or] 71,000 times the York moonlight. We 
cannot therefore be very far wrong in estimating the light of fu'l 
moon as about one-seventy-thousandth of the sunlight, anywhere 
oa the earth. This, however, is a compari-on which, because 
of the probably close agreement of the tints of the two lights, 
cin probably be made with minute accuracy: and we ust 
therefore not be satisfied with so very rough an approximation 
to the ratio as this 70,000. A lime light, or magnesium light, 
or electric are-light, carefully made and remade with very exactly 
equal brilliance, for each separate observation of sunlight and 
moonlight, might be used for intermediary. 
THE HYPOTHESIS OF ACCELERATED DE- 
VELOPMENT BY PRIMOGENITURE, AND 
ITS PLACE IN THE THEORY OF EVOLU- 
TION * 
[NX our days the student of the biological sciences may look 
forward towards his life-task with sincere gratitude. Grati- 
tude not only for what has already been achieved, and for the 
ends that have been attained in this domain, but more especially 
for all that which the future promi-es, since the sage whose 
mortal remains were lately deposited in Westminster Abbey has 
thrown the light of his genius over regions which hitherto were 
shrouded in deepest obscurity and has opened new vistas on old 
problems, of which man has been seeking the solution for many 
thousands of years. 
It is to him we have to give thanks that the dawn of a new 
life has commenced for those sciences; to him, moreover, we 
owe it that the twilight has only lasted a short time, and that the 
full light of day has shone so soon upon an extensive field, 
And if by this light we perceive numerous new problems, the 
existence of which was not even dreamt of before, and which 
cover the field of our work as far as the horizon reaches, still 
we notice that their shapes have obtained definite outlines. In 
future they may serve as milestones on our way onwards, before, 
when we were still groping in the dark, they wer2 as many 
stumbling-blocks which prevented us from advancing. 
If to-day I call before your mind the inage of this great re- 
former, it is not to give you an eulogy of Darwin, whose sudden 
death some months ago has filled with grief the whole civi- 
lised world. He is before my mind, becau e I belong to the 
generation whose youth coincides with that of the ‘‘ Origin of 
Species ;’’ a generation deeply filled with gratitude towards this 
great master. A gratitude bursting forth witb doubled intensity 
in him who enters upon a career in which he will have ample 
opportunity to continue work in that field of science to which 
he has become more and more attached through the inspirinz 
influence of Darwin. 
It is not only by the contents of his work that Darwin tikes 
hold of us, it is also his personal character which leaves such a 
forcible impression. The history of his life, his method of 
work, his amiable individuality, have excited our enthusiasm 
over and again, and always in an increasing measure. Simi- 
lar to other grand figures in the history of the world, who 
by their life and their example have perhaps wrought more than 
by their teaching—which at the hands of less eminent adepts 
soon took a dozmatic, z.e, a degenerate shape—this reformer of 
biological science has left behind him a remembrance which will 
be kept and transmitted by his followers with quite as much care 
and piety as the writings he has left. 
What strikes us most and all at first in everything emanating 
from him is his passionate honesty,” which has already become 
proverbial. Never did he pass over in silence, in the interest of 
his argument, a point which might eventually appear to be in 
favour of the oppo ite plea, In the enumeration and refutation 
of such points he was always quite as careful as in the collection 
* By Prof. A. A. W. Hubrecht. Inaugural Address delivered in the 
University of Utrecht. September, 1882. 
2 Cf. Huxley, Nature, May, 1882, 
of positive proofs. He was never biassed, unless biassed in the 
good sence of the term, z.c. enabled, when once he was of opi- 
nion that it was necessary to choose a decided side with respect 
to any dubious point, to devote to the careful consideration of 
this point not only hours, but if necessary months and years of 
his life,—months and years of daily returning observations con- 
cerning what appeared to be unimportant facts, which, however, 
when they were afterwards brought together, permitted him to 
draw highly important conclusions. 
Unlimited veracity and undaunted patience, two principal 
requirements of the true naturalist, thus found their most perfect 
incarnation in Darwin, and with these two for his guides, he 
brought together, from fur and near, building stones for the com- 
pletion of the grand structure which his mind had conceived. 
The quarries from whence he excavated those building stones 
were very different from those to which the scribes in biological 
science habitually resorted. It must be understood that since 
the appearance of Cuvier’s ‘‘ Le Régne Animal distribué d’apres 
son Organisation,” a reaction had sprung up against descriptive 
zoology which in many cases went further than Cuvier himcelf 
would ever have acknowledged. The numerous volumes of his 
excellent ‘‘ Histoire naturelle des Poissons ” furnish ample proof 
that Cuvier had always endeavoured to combine careful descrip- 
tion of the species and conscientious sifting of all the material 
concerning its life history, its geographical distribution, and its 
synonymy with the study of the comparative anatomy of the 
group to which it belonged. Several of his followers have, 
however, concluded that since researches upon the internal 
organisation of so many classes of animals allowed him to make 
most important deductions, it was from similar researches only 
that anything could be expected for the future. Their ambitious 
aspirations could not manage to forget that a combined investiga- 
tion by Cuvier and Geoffroy St. Hilaire was once described by 
one of the two in the following words :—‘‘ Nous ne dejéunions 
jamais sans avoir fait uae découverte.” __ 
And so 2 period was opened up in which our knowledge of 
the internal organisation of animals was not only increased on 
all sides and firmly based upon f cts by zealous workers, but in 
which this knowledge was gradually pu-hed into the foreground 
as the pre-eminent, as the only'true zoology. ‘The careful study 
of the species and its life history was left with a smile and a 
shrug of the shoulders to dilettanti and museum zoologists. In 
order further, to indicate how the results of researches of these 
men were looked upon as popular and unimportant, this new 
school invented the well-sounding name of ‘‘ scientific z»ology.” 
The eminent researches of von Siebold on parthenogenesis and 
on the freshwater fishes of Germany; Kolliker’s important 
monograph of the Pennatulids, &c., show that even its founders 
were subject to impul-es which drove them back into this very 
field, or rather that it was not they, but their less gifted 
followers from whom the c ntemptuous meaning which that 
combinati n of words gradually attained has emanated. 
Thus for a certain lapse of time the wind blew from a different 
quarter, and attempts have repeatedly been made to call into life 
classifications which were based upon certain points in the 
internal organi ation, points which were considered to be of the 
more importance the le-s they were visible. Fortunately the 
great masters to whom we owe comparative anatomy, and who 
have made it such as we know it in the pre-ent day, have not 
joined in this movement. Johannes Miiller’s “System der 
Plagiostomen” stands side by side with his ‘* Comparative 
Anatomy of the Myxinoids,” showing that this one-sided exagge- 
ration would never have been encouraged by himself. Gegen- 
baur, Huxley, &c., have similarly kept aloof from the ‘‘scien- 
tific zoologists” in the stricter sense, whose narrow-minded 
doctrines are still pullula’ing, be it in a somewhat modified form. 
At the present day it is not so much the internal o-ganisation 
which forms the shibboleth by which entrance is obtained to the 
holy circle of self-styled orthodox zoologists, but now it is the 
history of development, embryology, that gives the pass-word, 
Th's important branch of biological science has made gigantic 
strides of late ; it counted in its foremost ranks, among the most 
promising and large-minded, the man whom a cruel fate had 
doomed to find his deat: in the Alps of Switzerland, the talented 
Balfour. He never overvalued in a petty way the labours of 
the select batallion of which he was one of the leaders. In 
the rear of this army, however, voices are heard claiming infalli- 
bility for embryology, and the splendid generalisation: ‘the 
development of the individual is a repetition on a reduced scale 
of the development of the race,” must often serve to hide unripe 
