12 Prot. 
PROTOZOA. 
Contractile Vacuole . 
From his researches on various Infusoria , Fabre-Domergue (1) con- 
cludes (1) The contractile vacuole is only the reservoir for a system of 
canals which perforate the ectoplasm. (2) It may be considered as a 
dilatation of a contractile channel. It may be single, or represented 
by a variable number of dilatations along the course of the channel. 
(3) It may be entirely absent, as in Opalina , but the system of con- 
tractile tubes always exists, and is the essential part of the arrangement. 
Reproduction. 
Giard (1) follows Maupas in finding homologues of the polar bodies of 
Metazoa in the reproductive processes of Infusorians. The homology is 
most marked in the group Ciliata, where the conjugating forms are 
frequently quite different. Maupas’ figures are used and his deductions 
extended. 
Pouchet (2) discusses the reproduction of Noctiluca. 
Gruber discusses the phenomena of conjugation among various Ciliate 
types, and criticises the views of Hertwig and Maupas. 
Yerworn discusses the structure and reproduction of Difflugia lobo- 
stoma. 
ThiSlohan (2) has studied the Myxosporidia , and arrives at the follow- 
ing results : — (1) Th6 nucleus divides by karyokinesis. (2) The polar 
capsules are formed at the expense of small masses of plasma which are 
differentiated in the sporoblast and possess a nucleus. (3) The plasmic 
mass of the spore is derived from another portion of the sporoblast. It 
contains tAvo nuclei, and often a vacuole whose contents are stained red- 
brown by iodine. 
See also Stummer. 
IV.— PHYSIOLOGY. 
Sciiutt obtained throe distinct pigments from the chromatophores of 
the Peridiniece. The first, which he names “ phycopyrrin,” differs from- 
chlorophyll chiefly in its solubility in water ; the second he terms “ peri- 
dinin” ; and the third is either identical with or closely related to 
chlorophyll. 
The pigment of Euglena sangainea is closely related to and is perhaps 
a derivative of chlorophyll. Its formation seems to be connected with 
the intensity of the sun’s rays. Cohn has named it “ hoematochromin.” 
Visart. 
Pouchet (2) discusses the effect of reagents on Noctiluca . 
Schurmayer has an exhaustive paper on the effect of reagents upon 
Protozoa. After discussing the influence of heat and cold upon these 
