APRIL 16, 1914] 
fifteen years of age, who will afterwards be engaged 
in trade, represent roughly the type of school in which 
continuation classes can best be carried on. 
It is useless to make continued education of primary- 
school pupils compulsory without the provision and 
adequate equipment of schools for practical instruction 
in close relationship with the occupations of the pupils. 
The schools should thus do something to relieve the 
monotony and extend the outlook of the young work- 
man who, on account of the minute subdivision of 
manual labour, may spend his life upon one small 
detail of some product or process, and learn nothing 
beyond it. Industrial advance demands the produc- 
tion of intelligent and adaptable types of workmen ; 
and practical continuation classes offer a means of 
training them which is impossible under modern con- 
ditions of manual work. Mr. J. C. Smail, organiser 
of trades schools for boys under the London County 
Council Education Committee, has recently studied 
in Germany the compulsory system of continued edu- 
cation for boys from fourteen to eighteen years of 
age; and we may appropriately give here a statement 
of the conclusions arrived at by him with regard to 
such schools, as they have a direct bearing upon the 
foregoing remarks, which were written before the 
report was published :— 
(1) There has been, broadly speaking, a difference 
in ideals between Germany and Britain in the organisa- 
tion of technical courses. Germany is aiming at 
benefiting the nation by training properly all the 
workers through definitely specialised courses. Britain 
has organised so that individuals may secure what 
they think best for their own advancement. 
(2) The fundamental basis of any course of study for 
technical students must be their trade or employment. 
If this is recognised and acted on in the preliminary 
years from fourteen to eighteen there is little danger 
of work at more advanced stages, even if irregularly 
organised, being ineffective. 
(3) Germany is aiming at making good citizens and 
has realised that a gocd citizen must be a good 
workman. 
(4) Germany has come to believe that workshop 
training alone is insufficient to make a sound indus- 
trial nation; that it must be reinforced by adequate 
education specialised to trades. 
(5) This specialised education must include 
specialised calculations, technology, drawing, and 
citizenship. Munich also believes in trade work in 
the compulsory schools, Berlin does not. 
(6) Citizenship must be taught to enable the worker 
to recognise his individual position in the State, his 
position with respect to his employer and his fellow- 
workmen, his family and social duties, the relative 
position of his trade in his own country, and in the 
world’s commerce and industry. 
R. A. GREGORY. 
CYTOLOGICAL ASPECTS OF HEREDITY. 
— current number of the Quarterly Journal of 
Microscopical Science (vol. lix., part 4) will be 
of exceptional interest to students of heredity from the 
cytological point of view. Dr. L. Doncaster contri- 
butes a very useful review of the present state of the 
evidence with regard to the material basis of here- 
ditary transmission and sex-determination, under the 
title, ‘‘Chromosomes, Heredity and Sex.’’ He con- 
cludes that the arguments in favour of the view that 
Mendelian characters are determined by chromosomes, 
though very strong indirectly, are lacking in direct 
evidence. The direct evidence of a relation between 
chromosomes and sex-determination is much stronger, 
and various cases are discussed. The phenomena of 
sex-limited inheritance, now known to occur in various 
NO. 2320, VOL. 93| 
NATURE 
175 
groups of the animal kingdom, taken in conjunction 
with this relation, afford strong support to the view 
that the chromosomes play a very important part in 
the transmission of Mendelian characters, although the 
part played by the cytoplasm must also be taken into 
account. With regard to sex-determination difficulties. 
arise in connection with the fact that this has been 
shown in certain cases to be modifiable by environ- 
mental conditions, and it therefore seems probable that 
the sex chromosome is associated with a particular 
type of cell-metabolism, which in turn is responsible 
for sex-determination. 
A very important contribution to the discussion is 
made by Dr. R. R. Gates and Miss Nesta Thomas in 
“A Cytological Study of Q£nothera mut. lata and 
GE. mut. semilata in Relation to Mutation.’’ These 
authors find that in the ‘‘mutants”’ of the evening 
primrose known as ‘‘lata” and ‘‘semilata,” fifteen 
chromosomes always occur instead of the normal four- 
teen. The peculiar characters of these mutants are 
thus shown to be associated with the presence of an 
extra chromosome, which they are believed to have 
acquired by the abnormal distribution of both chromo- 
somes of one pair to the same daughter-nucleus in the 
reduction division, the actual occurrence of such 
abnormal distribution having previously been demon- 
strated by Dr. Gates. The authors maintain that 
mutations and Mendelian hybrids are not of the same 
nature but must be contrasted with one another, the 
former owing their origin to germinal changes (e.g. 
the presence of an extra chromosome), and the latter 
to recombinations of the parental characters. Dr. 
Gates adds a useful note on the meaning of the term 
‘‘mutation,” and the difference between ‘“mutations ” 
and “ fluctuations.” 
THE CURRENDS IN, BELLE ISLE S@iRATI 
i behaviour of tidal streams and currents in 
Belle Isle Strait, described by Dr. Dawson, 
Superintendent of Tidal Surveys to the Canadian 
Government, in a number of reports. the latest of 
which are before us, affords an example of the manner 
in which the various elements in a complex current 
may be distinguished one from the other. As the 
same may apply to other straits where the conditions 
are similar it should, therefore, be of more than local 
interest. The current in the strait is primarily tidal 
in character, and under normal conditions it will turn 
regularly; the flood running westward, and the ebb 
eastward with equal velocity. When, however, the 
moon is in high declination the resulting diurnal 
inequality causes one flood and one ebb in the day to 
be twice as strong as the other; the difference being 
much greater than that between ordinary or average 
springs and neaps. 
In addition to the tidal fluctuations, the water has 
a tendency to make through the strait in one direction 
more than the other, thus causing a continuous gain 
to eastward or westward, as the case may be. The 
overbalance in one direction which is superimposed 
upon the usual tide elements to which the term element 
of dominant flow is given, introduces complications, 
because larger in relation to the strength of the tidal 
streams, especially at neaps when weak. It may, in 
fact, be so strong as to reverse the ordinary tidal 
streams or prevent them from turning, although the 
fluctuation in velocity be well marked. 
The dominant flow, it is stated, cannot be attributed 
to local wind, because wind would produce merely a 
surface drift, whereas the dominant flow is that of the 
whole body of the water. It is, however, apparently 
1 The Currents in the Gulf of S!. Lawrence. By Dr. W. Bell Dawson. 
(Ottawa: Government Printing Bureau, 1913.) 
