> An extensive network of veins called a venous plexus are located on both sides of each of the lateral cartilages and in the sensitive structures of the hoof. The compression of these veins by the plantar cushion against the lateral cartilages or the coffin bone against the hoof acts as a “pump” to force the blood up the leg and back to the heart.

A horse is an extremely sophisticated biological machine, but it has no idea what makes itself tick. It has some limited mental model of the world around it and that's about it. Humans fare little better, but at least can make inch-by-inch progress through scientific study.

Such a creature that knew and felt itself perfectly, could at any point inquire the status of its own glycogen stores in its liver, could diagnose and micromanage its immune responses, could introspect accurately and with infinite recursion upon its own thoughts, seems hard to imagine, because if one were to set out to design such a creature, naturally its complexity would have to scale with the complexity it is attempting to self-model. Perhaps there is some sort of upper limit to the consciousness:complexity ratio that makes closing this gap impossible. (Or perhaps there isn't, and that would be just as fascinating.)

If nothing else, I would like to read a Borges story on the subject. Such a creature might inevitably be doomed to the same fate as Funes the Memorious.

Giraffes are at the very edge of physical adaption. In the fantastic Channel-4 TV series Inside Nature's Giants (https://en.wikipedia.org/wiki/Inside_Nature%27s_Giants) they dissect a giraffe and show how their anatomy/physiology is adapted to handle extreme blood pressure (because their heart needs to pump blood to the brain through the long neck against gravity). But that same pressure when sent down to the legs will burst their blood vessels. So how does cardiovascular adaptation work in this case?

Read these to find out;

1) How giraffes deal with sky-high blood pressure - https://www.bbc.com/future/article/20210803-how-giraffes-dea...

2) The Remarkable Cardiovascular System of Giraffes - https://www.annualreviews.org/content/journals/10.1146/annur...

3) How long limbs reduce the energetic burden on the heart of the giraffe - https://journals.biologists.com/jeb/article/228/20/jeb251092...

4) Giraffe dissection episode (must watch!) - https://www.youtube.com/watch?v=pkhztOqKYIc

PS: Inside Nature's Giants is one of the best scientific series which everybody should watch, particularly students. This is how evolution should be taught; all episodes on Youtube - https://www.youtube.com/results?search_query=inside+nature%2...