My understanding of Lamarkian evolution is that changes that occur to one animal's morphology are passed on to it's offspring. An example: A short necked giraffe stretchs for the tree tops. It's children can stretch further, and the next generation further still.
The experiment which disproves Larmark: Start breeding mice and cut off all their tails. You'd expect to, in short order, be raising new generations of mice which lack tails. Doesn't happen.
It sounds like, from the other posts, that Baldwin is talking more about "instinctual behavior". And here we get into tricky ground. Different species of birds make different shape and size nests. A bird raised away from it's parents will make the nest just the same (so it's not a learned behavior). Does this mean that the "program" for the nest resides in the genes of the bird?
Possibly, but I recall an interesting study about pregnant rats.
Pregnant rats build nests. If you raise a rat with it's mother in a nest, it will later go one to build a nest when it gets pregnant. Likewise, if you take the rat from it's mother and raise it without a nest, when it gets pregnant, it also builds a nest.
Now, here's the kicker. If you take either rat (nest raised and nestless) and keep them in a container with a warm bottom, when they get pregnant they don't build a nest.
Why? Well, when the female rat gets pregnant, her nipples swell and touch the ground. They get cold / irritated and the rat responses by building a nest to solve that problem. Illiminate the irritation, you illiminate the impulse and therefore no nest.
Now is nipple swelling programmed in the genes? Ya. Was it selected for because having a nest better ensures the survivability of the young? No idea.