Thomas E. Billings passed on another tid-bit in the long saga of why
plants devote energy to producing *fruit*, i.e., a seed hidden in a
yummy gift such that the plant gains widespread seed distribution when
an animal hauls the package away and later discards the hard part:

> a short excerpt (fair use under copyright law) from the article,
> "Berry Time", by Steve Howe

[...]

> It is obvious to a blackberry-picking biologist that this berry plant
> wants no mammal to eat its fruit and distribute its seed.

Here's a slightly different, but perhaps equally obvious viewpoint
from...

http://www.appbears.org/drbear.html

"...As the summer goes on and the plants grow, the bear's diet changes a
little and he begins to eat as many berries as possible. These include
blackberries, blueberries, strawberries, serviceberries, you name the
berry and he usually eats it."

I've picked enough wild blackberries, safely, comfortably, and joyously,
to be somewhat doubtful that Steve's "thorny attitude" is anything more
than a means to keep *grazing* mammals at bay.

Regards,
Rex Harrill