82 
clamours of the inshore fishermen against the purse-seine, 
a Committee of Senate was appointed, which was likely 
to result in additional regulative enactments. The rest 
of the essay contains an account of mackerel-canning, 
statistics of the fishery in 1880, the inspection laws, a 
chronology of the history of the fishing, a list of vessels 
engaged in the iudustry, and a table of the catch by 
American vessels in Canadian waters. 
A paper by Mr. Harrison Wright relates the history 
of the shad fishery in the Vale of Wyoming, on the north 
branch of the Susquehanna. The Indians caught shad there 
before white settlers came, about 100 yearsago. The white 
people used shad seines with great success until 1830, 
when the construction of dams for a canal put an end to the 
fishery altogether. There were about forty permanent 
fisheries, some of which had an annual catch of 10,000 
fish, weighing three to nine pounds each. It is suggested 
that the fishery might be restored by the construction of 
ladder-ways over the dams, and other improvements, 
_ together with a restocking of the river with young shad. 
A translation is given of a report on the Loffoden 
fishery in 1880 by Lieut. Niels Juel, the chief of the police 
administration, which has charge of public order, &c., at 
the fishery. This report is very interesting, but we have 
scarcely space to summarise it: we can only give a few 
of the prominent facts. The number of boats engaged 
varied from 1000 to 5000; the total number of fishermen 
was about 27,000, of whom about 13,000 fished with gill- 
nets, 10,000 with long lines, and 3000 with hand-lines. 
The author believes that the water-temperature most 
suitable for cod is between 35° C. and 44° C. The total 
yield of the fishery in 1879 was 25,000,000 fish, valued at 
5,000,000 crowns. In 1880 the yield was still greater, 
being only surpassed by that of 1877. 
Another paper in this appendix gives extracts from the 
official statistics of the Norwegian fisteries in general, 
and another is a transcript, from the London Quarterly 
Review, of an article on “ The Fish-Supply of London.” 
In the latter the opinion of very high authorities is quoted 
that the fisheries of the North Sea, small as its area is, 
are practically inexhaustible, and that trawling does not 
tend to exterminate any species of food-fish. 
Appendix D deals with the propagation of food-fishes. 
It contains twelve papers, which are, with one exception, 
reports on the work of the various stations of the Com- 
mission during the year. The exception is a paper on 
the “Repopulation of the Water-Courses of Belgium,” 
by Baron de Selys Longchamps. This essay shows how 
the waters of the Meuse and Scheldt have been rendered 
barren by the construction of dams and the pollution from 
factories ; and that it will be a matter of great difficulty 
to remedy this state of things by the construction of fish- 
ways and the purification of the rivers. 
The whole work of the Commission, from its institution 
in 1871 to 1880, is reviewed in a number of statistical tables 
prepared by Chas. W. Smiley. In the period in question 
43,000,000 shad were artificially hatched and released on 
the spot, 53,000,000 successfully transported ; 15,000,000 
of Californian salmon have been hatched and released on 
the Pacific coast, 31,000,000 transported to other States, 
and 4,000,000 sent abroad. Of the 31,000,000 transported, 
about 50 per cent. were successfully introduced into 
distant waters. In 1879 and 1880 61,000 carp were 
distributed. 
Then follow seven reports on the work of the various 
hatching-stations, in which occur, here and there, interest- 
ing accounts of experiments and inventions connected 
with the hatching apparatus. At Wood’s Holl experiments 
were made with a view to arranging an apparatus suitable 
for hatching cods’ eggs ; the experiments were only par- 
tially successful. It was at Wood’s Holl that Prof. Ryder 
carried on his researches into the embryology of the cod. 
Experiments on the artificial hatching of the Spanish 
mackerel were made at Cherrystone, Va. 
NATURE 
| 
a 
Lastly, we have to notice Appendix C, on Natural 
History and Biological Research. First, we have an 
account of the Annelida Chzetopoda collected on the 
Massachusetts coast by the summer expedition of Union 
College. Three genera and sixteen species are described 
here as new to science. Of these Thaumastoma is said 
not to belong apparently to any known family. As far 
as we can judge from the figure of the head given, the 
genus is allied to the Nereida ; but all the figures in the 
plates to this paper are rough and unsatisfactory. 
Mr. Coutance records some experiments on the effect of 
saline solutions of the same strength as sea-water, but of 
different composition, on marine molluscs. In all cases 
the solutions were ultimately fatal ; but it would be in- 
teresting to have these experiments repeated with some 
alterations: viz. the solution to be substituted for the sea- 
water gradually, instead of suddenly, and the natural 
conditions to be more nearly realised in all other respects 
save the composition of the medium. 
Prof. J. A. Ryder contributes a paper on ‘‘ The Import- 
ance of the Protozoa and Protophytes as the Primary Souree 
of the Food of Fishes.” He might have said simply Proto- 
phytes, since Protozoa are fed by these ; and it is obvious, 
since a small proportion only of marine animals feed on 
littoral algae, that marine life depends largely on pelagic 
Protophyta. The author reviews the evidence that most 
Entomostraca feed on Protozoa, and that these feed on 
diatoms, &c., while the Entomostraca constitute the food 
of vast numbers of fish. He gives evidence to show that 
the adult shad feeds while spawning, in fresh water, and 
that the newly hatched shad feed on exceedingly small 
and young Entomostraca. The paper is rather a popular 
essay than an original memoir. 
S. A. Forbes finds that the earliest food of the young 
of Coregonus albus in Lake Michigan consists almost 
entirely of Copepoda of the species Cyclops Thomasi and 
Diatomus sictlis. 5 
Prof. Ryder, in another paper, describes some success- 
ful experiments in retarding the development of shad ova. 
It was found impossible to develop them at 35° F. or at 
45° F. Ovakept moist on flannel trays at 52° F. were 
killed by fungus, but the development proceeded at the 
rate of nine days for the embryonic period. In an ex- 
periment in which glass McDonald jars were used with 
water from the Potomac when the river was at the tem- 
perature of 51° F..to 57° F., development took place 
normally, and hatching was retarded till the thirteenth to. 
the sixteenth day. The embryos were lost by accident, 
but the author thinks it would require about twenty-five 
days at this temperature to absorb the yolk, and thus, 
if the same success could be insured on board ship, there 
would be ample time to transport embryos to Europe. 
Prof. Ryder’s remarks at the end of this paper, on “ The 
Rationale of Retardation” somewhat neutralise the satis- 
faction experienced in reading the account of his practical 
work. In the present state of science it is scarcely allow- 
able to talk of the nucleus as a “ directive dynamic centre,” 
because the phrase has little definite meaning. It is not 
true that the division of a nucleus has been described 
by Flemming under the terms “ systole” and “ diastole” ; 
that author’s use of those words referred to certain alter- 
nating movements in a nucleus previous to its division. 
The division of the nucleus does not give us a complete 
explanation of the phenomena of retardation. It is a 
truism that retardation of development means diminution 
in the rapidity of the rate at which cell-divisions take 
place ; but to talk of the w/s essentialis of segmentation 
residing in the nucleus is about as instructive as an 
attempt to localise the horologity of a cloc’, the ws essem- 
tialis of a steam-engine, or the situponability of a chair. 
The Report for the year 1882 was published at the end 
of last year, only a few months after the issue of the 
volume for 1881. In some respects this, the most recent 
annual Report, is the most interesting of the whole series, 
[May 28, 1885, 
