ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
523 
Centropagidm. He begins with a discussion of their systematic posi- 
tion, and proceeds to the genus Diaptomus , the species of which are 
divided into three sets — the casfor-group, the salinus-gvoup, and the 
cseruleus- group. 
Male Gonads of Cyclops.* * * § — Herr A. Steuer follows Ishikawa in dis- 
tinguishing, in the testis of Cyclops, &c., three zones of formation, grow- 
ing, and ripening. These are readily observed in the proper season, but 
the first cold day of late autumn immediately stops all reproductive 
processes, and the organ begins to be reduced. The author describes 
the testis, a vas deferens, and spermatophores, and his results are, in the 
main, confirmatory of those reached by previous workers. 
Parasitic Copepoda of Fish from Plymouth, f — Mr. P. W. Bassett- 
Smith, surgeon B.N., at the suggestion of the editor of this Journal, took 
up when stationed at Plymouth the study of the Copepods found parasitic 
on fish there. A collector is quickly struck by the much greater sus- 
ceptibility of some fish over others, and the large number of parasites 
found on them individually. It is rare to find a fairly grown cod 
without a number of specimens of Anchorella uncinata attached to the 
folds about the lips, and in the gill-cavity. In its mouth and on the 
palate will be seen frequently half a dozen specimens of Caligus curtus ; 
on the gills, deeply imbedded, Lernsea branchialis ; and on the body sore 
places where numbers of Caligus muelleri have been fixed. Gurnards, 
too, are very prolific, both in variety and number of specimens. After 
examining a large number of fish harbouring parasites, the author was 
led to the conclusion that in the great majority of cases, their presence 
is not prejudicial to the life of the fish, for (1) the fish bearing them 
are generally mature ; (2) there were rarely any ulcerated surfaces 
found around or near their attachment; and (3) the individual fish 
are generally well nourished. To this, however, there are certain, 
exceptions : Lernsea branchialis and its allies must be a constant source 
of drain of nourishment and also cause great irritation. The author 
describes no less than seven new species. 
Histology of Muscles of Cirripedia.f — M. A. Gruvel has made a 
study of some points in the minute anatomy of the muscles of Cirripedia, 
the chief species of which he has examined. He recognises in them 
three forms of muscular tissue which he distinguishes as : (1) striated 
non-arborescent fibres ; (2) striated arborescent fibres ; (3) smooth non- 
arborescent fibres ; that kind of fibre which he and other authors have 
distinguished as smooth and arborescent, is not muscular at all, but is 
of the nature of connective tissue. A short description is given of each 
of the kinds of tissue which the author enumerates. 
Early Development of Lepas fascicularis.§— Mr. M. A. Bigelow has 
a preliminary notice of his studies on the development of this Cirriped, 
which were commenced before the observations of Groom were published. 
He finds that the ectoblast is separated from the mesentoblast by four 
divisions. The four blastomeres thus formed rapidly divide, and grow 
* Yerh. Zool. Bot. Ges. Wien, xlvi. (1896) pp. 242-54 (1 pi.), 
t Ann. and Mag. Nat. Hist., xviii. (1896) pp. 8-16 (4 pis.), 
t Comptes Rendus, cxxxiii. (1896) pp. 68-70. 
§ Anat. Auzeig., xii. (1S96) pp. 263-9 (9 figs.). 
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