A part only of the thickenings are filled with lime granules.
These occur as thickenings and down-growths of the epithelium into the corium.
The olfactory pits are barely indicated as thickenings of the nervous layer of the epiblast.
He saw these thickenings of the fog, he heard their voices, the tapping of their cautious sticks, their shuffling feet as well.
In the new wing, protected by these thickenings, are air-tubes, which divide and branch into all parts of the wing.
These thickenings are the first rudiments of the ventral nerve ganglia.
These thickenings appear to give origin to the lateral ciliated plates.
The supra-œsophageal ganglia are formed independently of the ventral cords as two thickenings of the procephalic lobes (fig. 205).
The supra-œsophageal ganglia originate as thickenings of the epiblast of the procephalic lobes.