![](/drem/stage21/labels/S25L.gif)
![artifact fracture(s), artifact space(s), cerebral aqueduct (longitudinal section), intermediate zone, marginal zone, osteogenic layer, subarachnoid space, ventricular zone](/drem/stage21/Z0/S25N.jpg)
![](/drem/rulerbg.png)
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Carnegie Embryo #4090 | Location: 2-9
Keywords: artifact fracture(s), artifact space(s), cerebral aqueduct (longitudinal section), intermediate zone, marginal zone, osteogenic layer, subarachnoid space, ventricular zone
Source: The Virtual Human Embryo.