All the parts laid out and put together for the flex-trunk elephant.
Pull the tail and the trunk raises.
Small slot at the back through which the tail runs.
In the view from the underside you can see where the tail runs through the body and connects to the trunk tendon.
Here's a Vine animation of the assembled prototype. Standing, as it happens, on my copy of Origin of Species.
Colour next. I'm going with pink. Darwin would be proud.