ZOOLOGY AND BOTANY, MICROSCOPY, ETC. 
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conjugation the amount of glycogen in the cell is reduced to a minimum. 
After the reconstruction of the macronucleus and the re-establishment 
of the oxydation-function, there is a marked increase in the amount of 
reserve-material, and the amount reached lasts for five to six months 
after conjugation. It appears that the individuals that conjugate differ 
markedly in their glycogen-content. After conjugation the fat is 
mainly represented by neutral fats. There is little in the way of 
cholesterin esters. Before conjugation the large drops of neutral fat 
disappear; numerous fat droplets of another kind appear, and among 
these small, but increased, amounts of cholesterin esters and large 
quantities of what are probably fatty acids. After conjugation the 
neutral fats are restored. Continued metabolism paralyses the 
macronucleus ; conjugation frees the macronucleus from toxic 
inhabitants. J. A. T. 
Function of Contractile Vacuole. — Adolf Herfs (Archiv.f. Pro- 
tistenkunde , 1922, 44, 227-60). An interesting series of observations 
on Parametrium , Gastrostyla, and Nyctotherus, which go to show that 
a function or the chief function of the contractile vacuole is to pump 
out water from the cell and thus protect the cytoplasm from dilution. 
J. A. T. 
Study of Opalina. — Stefan Konsuloff (Archiv. f. Protistenkimde , 
1922, 44, 286-345, 2 pis., 6 figs.). The pellicle in Opalina is provided 
with myonemes which bend the margin in the flat species and produce 
longitudinal ridges in the cylindrical forms. The bendings and ridgings 
help in steering. There is an internal framework of supporting fibrils 
in a network, strained by the functioning of the myonemes. The body- 
form tends to downward movement (geotaxis). The ectoplasm may 
pass from a homogeneous to a vacuolated state. What have been called 
“ disc-like corpuscles ” are true macronuclei which divide amitotically. 
They disappear in the reproductive phase. What have been called 
“ nuclei” are the micronuclei. The chromidia which pass out from the 
nuclei disintegrate. In Opalina ranarum there are excretory vacuoles 
(non-contractile) and a network of canals. Waste-bodies, often minute 
crystals, are common in the endoplasm. Cysts may be formed when 
the conditions are unpropitious or in some other cases. There are 
macro- and micro-gametes in 0 . ranarum and anisogamous conjugation, 
resulting in cystozygotes. There is nutritive osmosis and some evidence 
of extra-cellular digestion of adjacent particles. The genus should be 
placed in the Ciliata near Anoplophrya , Hoplitophrya , Discophrya, and 
Opalinopsis. J. A. T. 
Structure and Habits of Spathidium spatula. — Lorande Loss 
Woodruff and Hope Spencer (Journ. Exper. Zool., 1922, 35, 189-202, 
1 pi., 8 figs.). This ciliated Infusorian does not possess trichocysts, 
and consequently cannot paralyse its prey by this method. It "has 
trichites in the oral region, like a supporting paling, but there is no 
conclusive evidence that they are the locus of the poison. There are 
clearly defined micronuclei. The food is limited to small ciliates, but 
not to members of the genus Colpidium. It seems to come in contact 
