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SUMMARY OF CURRENT RESEARCHES RELATING TO 
does not send out fine pseudopodia ; in the place of these there is a long 
delicate, hyaline flagellum, by means of which the organism is capable 
of effecting lively swimming movements. The brownish-yellow colour 
by which living examples of D. speculum are distinguished, is due to 
numerous small rounded bodies which fill the protoplasm of the body ; 
after the death of the organism these become of a greenish hue, in con- 
sequence of chemical decomposition ; but it could not be satisfactorily 
determined whether one has to do with small symbiotic algar cells or 
with endogenous chromatophores. The nucleus, which lies in the 
middle of the body, is ellipsoidal and vesicular, and is surrounded by a 
delicate membrane ; it consists of a vacuolated cortical layer and a 
central chromatin-body, and has, consequently, a certain resemblance to 
the central capsule of a very small Badiolarian. 
The Dictyochidae are, however, sharply separated off from the 
Eadiolaria by the complete absence of pseudopodia, and by the 
possession of a flagellum. The appearance, also, of double individuals 
is a point of importance, as conjugation has never yet been observed in 
the Eadiolaria, while it is very common among the Flagellata. The 
possession of a siliceous skeleton is an important point of distinction, 
and it is necessary to make a special order of the Mastigophora for the 
Dictyochidae ; this may be appropriately called the Silicoflagellata. 
Colouring-Matter of the Peridiniese.* — Dr. F. Schiitt finds in the 
chromatophores of the Peridiniese three distinct pigments, viz. : — 
(1) Phycopyrrin ; obtained as a dark reddish-brown fluid by crushing 
the Peridinieae in a very small quantity of distilled water. The 
spectrum is nearly related to that of chlorophyll ; it exhibits the strong 
absorption-band I, as well as, with a certain concentration, the band II ; 
the end-absorption begins in the green. Phycopyrrin is readily soluble 
in alcohol, ether, carbon bisulphide, and benzol ; the solution in the 
last three solvents is yellow, but has essentially the same spectrum as 
the aqueous solution. Its chief distinction from chlorophyll is in its 
solubility in water ; its chemical properties seem to indicate that it is a 
connecting link between this substance and the phycoerythrin of the 
Florideae ; it is quite distinct from the diatomin of diatoms. In addi- 
tion to this a-phycopyrrin, the author describes a /^-phycopyrrin, differing 
from it in unimportant particulars, and probably a derivative from it. 
(2) Peridinin; obtained by digesting for a short time in alcohol 
the Peridiniese which have already been extracted with water ; a wine- 
red solution is thus obtained, presenting a very different spectrum from 
that of chlorophyll ; the band I is but faintly indicated, while a 
moderately sharp band appears between X 64 and 63. Peridinin is 
readily soluble in alcohol, ether, chloroform, benzol, carbon bisulphide, 
and glacial acetic acid ; it appears to represent in the Peridiniese the 
xanthophyllin of flowering plants. 
(3) A substance was further obtained identical with, or very nearly 
related to, the chlorophyll of plants. 
Foraminifera of Faroe Channel. f — Mr. F. G. Pearcey gives a 
revised list of the Foraminifera found in the Faroe Channel. He dis- 
* Ber. Deutsch. Bot. Gesell., viii. (1890) pp. 9-32 (2 pis.). 
f Proc. and Trans. Nat. Hist. Soc. Glasgow, ii. (1890) pp. 163-79 (1 pi.). 
