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POPULAR SCIENCE REVIEW. 
It is quite certain that the Yolvox does not remain as Volvox 
through the winter. You may search for it assiduously, but you 
will not find it ; therefore we may fairly assume that it takes 
on some quiet condition, possibly more than one, perhaps so 
unlike its summer shape, as to have deceived the most careful 
observer. It would not be difficult for a great number to be 
collected and placed in a large body of pure water, covered 
with muslin to keep out other bodies, and exposed to the sun 
and air, at the end of summer, and the whole to be closely 
watched : some new points will I am confident be obtained. 
DESCRIPTION OF PLATE. 
Fig. 1. Ordinary appearance of Yolvox Globator. — a a, Zoospores ; b, 
Gemmae, or young Yolvoces. 
„ 2. Zoospores magnified. — a a , Zoospore ; b, Cilia ; c, Membrane of the 
sphere ; d , Yacuole ; e, so-called Eye-spot. 
„ 3. Stellate shape of Zoospores. 
„ 4. Zoospores of the Algae. 
„ 5. Enlarged Zoospore before dividing. 
„ 6, 7, 8, 9. Different stages of division. 
„ 10, 11. Ultimate division. — a, Enveloping mucus ; 6, Cilia. 
„ 12, 13. Stato-spores, or quiet spores. 
„ 14. Young Yolvox producing Antherozoids. — a a, Antherozoid still 
retained in the mucus envelope ; b b, Zoospores of parent. 
„ 15. Shows the Amoeboid change. — a, Commencement ; b, Moving- 
Zoospore. 
„ 16. Ciliated group of cells in autumn. 
„ 17. Winter-spores. 
