Universlty of Manitoba, ln Partîal Fulfiìlment - MSpace at the ...

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5.3 INVFSïIGATtON 0F THE TERAToGENTC EFFECT:0F t;/lNpor,ilNG
ln an attempt to define some of the factors leading to abnorrnal
development after windowing, several experiments were performed to
investigate varlous aspects of the windowi.ng technic, ln one group of
experiments eggs were trear:ed bv vîbration, of by the applicatíon of
parafî lm and a plasticine iing, wÌthout windowîng. ln other experiments
the ¡ntroduced air space was obl iterated at the time of windowing.
5.3.1 Vibf¡itiori óf UnoÞened Eggs,
,.m;ratÎonProducedbythedentalsandIngdiscusedto
cut the shell wlndows, unopened eggs were vlbrated for J0 seconds wlth a
carborundum ball mounted on the dr¡ll. Thls procedure was performed ât
0, 26 and 33 hours of încubatlon, and the eggs then relncubated to a total
of / days without belng turned.
Tables 10 and tt show the mortal ìty and malformation rates for the
three experîmental groups and the controls. Bêcause of the relatively
small numbers ín each group, values are not converted to percentages.
Desplte the small numbers ît is clear thðt V¡brat¡on by itself is not
responsîble for the teratogenic effect of the windowíng techníc. There
werè no open èord defects in any of the experimentêl or control groups.