AuGusT 27, 1914] 
NATURE 
673 
wegian coast, and that each individual sample shows 
the same predominance of the 1904 class. It is also 
equally well shown in seven samples of ‘“‘large 
herring”’ taken during the winter of 1913-14. 
The next step in Dr. Hjort’s argument is based | 
on a study of the fishery statistics showing the fluc- 
tuations in the total yield of herrings of the different 
kinds. He is able to show that a marked increase 
of the yield occurred in those years in which the 1904 
class became prominent. 
The report then goes on to a study of the cod and 
haddock, and evidence is produced of a similar series 
of phenomena in the case of these fish. Again, the 
1904 year class is predominant for a number of years, 
and its abundance gives rise to a successful fishery. 
Summing up the whole matter, Dr. Hjort claims 
that the renewal of the stock of fish does not take 
place, as in any human population, by means of a 
more or less constant annual increment in the form 
of new individuals, but that, in the case of the species 
investigated, it is of a highly irregular character. 
‘At certains intervals, year classes arise which far 
exceed the average in point of numbers, and during 
their lifetime, this numerical superiority affects the 
general character of the stock, both as regards quan- 
tity and quality, thus again exerting a decisive in- 
fluence upon the yield of the fisheries in both respects.”’ 
These rich year classes make their presence felt when 
they are still quite young, and their influence on the 
yield of the fisheries extends through a number of 
years. It should, therefore, in future, by means of 
properly organised investigations, be possible to 
ascertain beforehand the probable general course of 
the fisheries over a series of years. Such predictions 
will, of course, be liable to be upset by special cir- 
cumstances, both of a general and of a local character. 
Nevertheless, there is now good reason to hope -that 
indications of great practical value may be given, if 
the methods of investigation advocated by Dr. Hjort 
are continued upon an adequate scale. Be Je As 
PawDIes OF TROPICAL: GDISEASES.1 
a report consists of the report of the committee 
(2 pp.) and six appendices, the first of which 
deals with anti-malarial measures in the Crown 
Colonies and protectorates, etc., the remainder with 
reports of the work done in various laboratories. To 
consider, first, Appendix I. The data in this appendix 
are mainly statistical. They seem to us to be deficient 
in two ways. (1) The figures are not scrupulously 
accurate, or at least differ from other official figures. 
(2) Information is lacking which seems to be essential 
to an appreciation of the meaning of the figures. Of 
want of accuracy, the following are examples. On 
p. 11 in the Mauritius report the number of deaths 
ascribed to fever (malaria included) is given as 4408, 
whereas in the annual report for Mauritius the deaths 
due to malaria only are given as 4619. Again, under 
the heading, ‘‘Government Hospitals,’ we find mala- 
rial fever: admissions 2321, deaths 30, whereas in 
the annual report for Mauritius we find 3063 cases of 
malaria, and 43 deaths. The discrepancy here may be 
due to the fact that in the latter case other than hos- 
pital cases are recorded, but if this is so, at any rate 
they find no place among the data in this report. 
Again, comparing the figures given in this report 
and in the annual medical report for the Straits Settle- 
ments, we find the figures for malarial admissions to 
be 9172 and 9474 respectively, a difference of 302. 
In the corresponding reports for Nyasaland we find 
the population given as 1,000,659 and 1,001,895 respec- 
1 Report of the Advisory Committee for the Tropical Diseases Research | 
t 
Fund for the Year 1913. 
NGws2330, VOL. 93] 
| 73 deaths, 5; admissions, 1; deaths, to. 
tively. In the Southern Nigerian report (p. 35) we 
find the following puzzling figures under malarial 
fever, viz. :—Admissions, 6; deaths, 10; admissions, 
And again, 
under ‘‘Government Hospitals,” we find the admis- 
sions given as 9687, and two lines further down as 
1365! Under “Blackwater Fever’’ four deaths are 
recorded, but no admissions are given, and it is only 
by referring to the annual medical report that we find 
that the number of cases in the colony was twenty- 
three. Not to pursue the subject further, we would 
only add that in our opinion the heading, ‘‘ Deaths 
Ascribed to Fever,’ is ambiguous, as apparently some 
medical officers have found it to be, for some change 
the heading to ‘t Malaria Fever,’’ others sav “ malaria 
included,’ whereas others again subdivide it into 
malaria, typhoid, and non-specified fevers. We think 
this heading should be changed to ‘‘ Diseases During 
the Year,’’ and divided into various sub-headings, e.g. 
malarial fever, blackwater fever, etc., with the addi- 
tion, if necessary, of unclassified fevers, and in each 
instance where possible cases as well as deaths re- 
corded, as is done under heading 6 ‘t Government 
Hospitals.” 
The second criticism we have to make is that in- 
formation is lacking which is necessary to give the 
figures their full value. While dreading to suggest 
any addition to the really burdensome labours of those 
who have to compile these reports, yet we cannot help 
feeling that a mere record of population and malarial 
deaths tells us less than we ought to know. In our 
opinion, for these figures to be really of value we 
should know, besides the total population, that of each 
race and the deaths in each race. For instance, we 
are given, on p. 14, the European, Chinese, ‘‘ other 
races,’ and Malay population of the Straits Settle- 
ments, but while we are told that the total births are 
more than 20,000, we are given no idea as to what 
races were responsible, and similarly we cannot tell 
among what populations the malarial deaths occurred. 
We have dwelt on these points because it seems to us 
that sooner or later the question of the compilation 
of the figures in reports of this kind and in the annual 
medical reports must be seriously considered. It is 
scarcely an exaggeration, we think, to say that at pre- 
sent no two annual medical reports are based on 
exactly the same plan, and we actually find that the 
official year is not identical in all. One point will not 
be disputed, viz., that absolute accuracy is necessary, 
and this is by no means an easy matter to attain, as 
everybody knows who has had to make up tables of 
figures. Whether these matters should not be in the 
hands of trained statistical officers, instead of being 
thrown on the shoulders of already overworked medical 
officers is a matter for consideration. 
It is impossible to give shortly an adequate notice of 
the various researches recorded in appendices ii.—vi., 
as the subjects differ widely. It is evident that much 
valuable research is being done and interesting results 
got, but it occurs to us whether practical results—and 
we think we may assume that this is the main object 
of most of these researches—could not be got more 
quickly if the forces now scattered in various directions 
were to some extent concentrated on certain problems. 
For instance, we consider that each of the reports on 
the use of salvarsan in yaws (three in number) is more 
valuable than it would have been if it had stood alone. 
On ankylostomiasis we have only one report. It 
would be a gain to check the results recorded in it by 
experience elsewhere. So while not wishing to limit 
in any way a man’s predilection, we think that 
coordination would be of advantage. The report is 
priced at 2s. 4d., but we hope that every medical 
officer receives a copy gratis. IW WE Ss 
