April 13, 1871] 

jacent. Each course occupies from 50 to 100 hours during a 
term of four months and a half. Some professors go with 
their students through a complete course of elementary 
instruction, whilst others leave this chiefly to private study, 
devoting the greater part of their time to inducting their 
pupils into the method of especial research. The atten- 
dance of students at the lectures is ensured by the cir- 
cumstance that the Natural Sciences form part of the 
objects in which medical men, chemists, and teachers, 
are examined before they are allowed to enter upon the 
exercise of their calling. We are informed that, at a 
University with nearly 7oo students (each remaining 
generally eight terms), some fifty would attend, within 
one term, the course of Natural Philosophy, or Botany ; 
about twenty-five that of Zoology, or Comparative 
Anatomy ; from fifteen to twenty that of Mineralogy, or 
Paleontology ; and about thirty-five that of Geology. 
These were the numbers usually seen in the lecture- 
rooms, but there were, of course, other students who 
were prevented from attendance by various causes. 
The majority of those students who are desirous of 
receiving a perfect scientific education, and have the 
means for it, take advantage of the great variety of col- 
lections and instructors by prosecuting their studies at 
two or more Universities, finishing them at those places 
which offer the largest collections, and, in natural com- 
bination, the best instruction. 
It may be mentioned here that the teaching of Science 
in German Universities is not entirely dependent on 
the public collections. Beside the staff of “ ordinary” 
professors, there are younger men attached to the 
University, who have the right to teach, but can make 
only such use of the collections as the ordinary pro- 
fessor is disposed to grant. Most of them select, for 
their course of lectures, branches in the teaching of 
which they can dispense with the collections of the 
Museum—as, physiology of plants, histology and micro- 
scopy, history of development, general biology. This 
institution of ‘‘ private docents,” as they are called, is 
valuable not only to the students, but also to the body of 
instructors, inasmuch as it forms a preparatory school for 
men who intend to undertake the duties of an ordinary 
University teacher. The presence of an able and popular 
“private docent” has also not rarely had the beneficial 
effect of exciting to fresh exertions the ordinary professor, 
who had gradually lapsed into a course of stereotyped 
lectures. Nevertheless this institution can be regarded 
only as supplementary to the system of scientific educa- 
tion which is principally carried out in connection with 
the Museums. 
We are not aware that there has ever been any lack of 
men combining an exact knowledge of some branch of 
Natural History with the aptitude for teaching it; nor 
have we ever heard of complaints that the duties of 
teaching seriously interfered with those of the curator- 
ship ; on the contrary, their union in one individual can 
have and has had only a beneficial effect. As teacher he 
knows best how to regulate the accessions and modify 
the arrangement of the collection, so as to meet the re- 
quirements of, and to be in accordance with, his system 
of teaching ; and as curator he takes care that those parts 
which are not in direct connection with the lectures are 
not neglected, or that valuable specimens are not sacri- 
NATURE 

463 

ficed for temporary purposes in the lecture-room or 
student’s laboratory. Work in the Museum is as neces- 
sary for the training of the students as attendance in the 
lecture-room ; and it is the duty of the teacher to devise 
suitable objects of research for his pupils. But if he had 
not the management of the collection, how could he be 
certain that the materials required are present, or will be 
made available? Would it be possible for him to super- 
intend the student’s work in a place where he is not the 
master? Were those duties assigned to two individuals, 
they would soon clash, to the injury of the service expected 
from the Institution. 
The existence of numerous large or well-adapted collec- 
tions, their utilisation for educational purposes, and the 
devotion of adequate time to instruction, are among the 
principal causes which have rendered the system of scien- 
tific education successful throughout Germany. But we 
must not forget that this success is due to the Universities 
only, and is limited to the classes receiving a University 
education. In the schools of lower degree, Science (with 
the exception of chemistry and natural philosophy) is only 
taught in the form of book-knowledge, in which the pupil 
takes but little interest, and therefore it has no great or 
lasting influence on the culture of his mind. 


THE DESCENT OF MAN 
The Descent of Man, and Selection in relation to Sex. 
By Charles Darwin, M.A., F.R.S., &c. In two volumes, 
Pp. 428, 475. (Murray, 1871.) 
Il, 
fl seals selection in relation to sex has been an impor- 
tant factor in the formation of the present breeds of 
animals was more than indicated in the “ Origin of Spe- 
cies,” and the theory has since been especially worked 
out by Professor Haeckel. It includes two distinct hypo- 
theses. One is that in contests between males, the weakest 
would go to the wall, and thus either be killed outright, or 
at least debarred more or less completely from trans- 
mitting their characters to another generation. This may 
be regarded asa particular case of Natural Selection, 
and may be compared with the theory of protection 
by mimicry, suggested by Mr. Bates, and carried out 
by him and by Mr. Wallace. But though in the 
lists of Love the battle is often to the strong, even 
more frequently it is to the beautiful. This introduces a 
new process, of which the effects are not nearly so obvious 
as those of Natural Selection, either in its simplest form 
or inthe more complicated cases of mimicry, and of sexual 
selection by battle. Many circumstances must combine 
in order that the most successful wooers shall have a larger 
and more vigorous progeny than the rest. In the first 
place, all hermaphrodite and all sessile animals may be 
excluded, and also those cases in which sexual differences 
depend on different habits of life. Mr. Darwin then 
shows that secondary sexual characters are eminently 
variable, and that males vary more than females from the 
standard of the species, a standard determined by the 
young, by allied forms, and sometimes by the character 
of the male himself when his peculiar functions are only 
periodical, or when they have been artificially prevented. 
Moreover it is the males who take the active part in pair- 
ing, and who not only fight for the possession of their 
mates, but display their colours, their voice, or whatever 
