ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
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division (Noctiluca and many Metazoa). The intranuclear body of 
Euglenci and other allied forms is equivalent to the attraction-sphere 
and not to the centrosome of the Metazoa. Chromosome-formation is 
first seen in the Flagellates in the form of rods whicli arise by the union 
of the previously scattered chromatin granules. They form in typical 
though primitive Metazoan manner in Noctiluca and Euglypha, and all 
Metazoa pass through these stages in preparing for mitosis. 
Minute Organisms in Sea-water.* — Dr. H. H. Dixon and Dr. J. Joly 
carried on last summer an extensive series of tow-nettings in Dublin 
and Killiney Bays in the hope of finding coccoliths. They obtained not 
only a very large number of these, but numerous other interesting minute 
forms. The coccoliths were first obtained attached, along with grains 
of sand, to the test of a Protozoan resembling Difflugia ; but later, by 
the use of a centrifugal apparatus or by straining sea-wator through 
fine silk, they found enormous numbers of free coccoliths. Calculation 
showed indeed that 200 were present in 1 ccm. of a sample of water 
taken on a clear day. Among these a few coecospheres were present. 
The authors’ observations on the coccoliths lead them to believe that 
these remarkable structures contain some organic matter between the 
two constituent valves. With the coccoliths occurred numbers of an 
apparently new Protozoan of the genus Difflugia, to which they give the 
name of D. thalassia. In a few cases chains of this form were found 
resembling the catena already known in Geratium tripos. Among other 
interesting forms were species of Tintinnus, one new, numerous members 
of the Peridineae, and certain peculiar new structures of spherical shape 
furnished with T-shaped spicules or peltate scales, to which the names 
of Echinosphere and Peltasphere respectively have been given. Other 
structures closely resembling Ehrenberg’s Xanthidia and Pyxidicula 
were found. These were described by Ehrenberg from the chalk, and 
the latter, at least, were hitherto not known to be recent. They are 
probably encysted Protozoa. The paper is of great interest and im- 
portance. 
Parasitic Infusoria in Domestic Ruminants. f — Herr Adolf Gunther 
has made a series of observations on the Infusoria of the stomach in 
sheep, goats, and cattle, and on the methods of infection. He finds that 
the parasites are confined to the two first chambers of the stomach where 
the reaction is alkaline, and are speedily destroyed by the acid of the 
omasum and abomasum. The Infusoria can be destroyed without injury 
to the host by doses of hydrochloric acid administered in capsules, or 
less effectually by citric acid. A series of experiments showed that in 
lambs on milk diet the first two chambers of the stomach had an acid 
reaction and Infusoria were absent, while a diet of hay and water resulted 
in the production of an alkaline reaction and the appearance of the para- 
sites. A diet of oil-cake and water did not result in infection. By 
prolonged boiling it was found that hay could be sterilised, and sheep 
fed with this did not show Infusoria. There is thus reason to believe 
that hay is the ordinary cause of infection, but infusions of hay failed 
to yield the characteristic parasitic forms, and the encysted stages of 
these are unknown. 
* Sci. Proc. Roy. Dublin Soc., viii. (1898) pp. 741-52 (2 pis. and 6 figs.). 
t Zeitschr. f. wiss. Zool., lxvi. (1899) pp. 529-72 (2 pis. anti 2 figs.). 
