THE DEVELOPMENT F FISHES
75
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,
the embryoïs rich supply of blood and food, the brain .—
(Cerebellum) and nervous system do not, it seems 'cannôt,
develop iri_the normal manner. The materials
but they are too crowd_ed together and the ,tissues:remainîi
an
elementary
in "a sense on‘e m'ay rca—ll" them
degenerate. ,“
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In the opposite extre‘ïne, plenty of Space andlite of1n'o
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yolk, the embryois com—
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lete
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and Appendiœlària ,the — '
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brain is not developed
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at all,
is there any;
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'head or denite vascular
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{Similarly in- the Tee-À —
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means rapid
but mçom,
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plete development,=as in
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-
the Clupeids ; a sufPf°
ciençy of yolk aä spaçe
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gives.more”ffullyeformed _Deag);,_i
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1‘àrVæ, as in… forms, :wîth ;ÿ‘p’ïînhaî” Bpdg“hä“
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blood,. gi113,zand
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Such
deg—fee isnot; reachedbyth€spfatlafvaf°1 Î
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