How is the "'s" related to the death of a person or of an animal

Question

"Camel hair" is, among other things, the hair of a camel.

Since we talk about "sheep's wool" or "lamb's wool", why don't we use the "'s" after camel in the case above?

Perhaps some historical reason might exist, but, as a not native of English language I'm wondering if I have to learn all the cases in reference to any specific animal or if there exists some guidance, if not some rule, helping to understand this problem.

For example, if the separation of an animal's part implies its death, can I be sure that the "'s" has to be dropped, as in the case of "calf skin"?

If this is a real rule, could we extend it to human beings? For example, if one—a doctor, for example—talks about my heart, after my death, should s/he say "Carlo's heart" or "Carlo heart"?

Answer 1

You are assuming a relationship where none exists. This has nothing to do with the animal's death.

"Camel hair" is the name given to the textile fiber obtained from a camel. It's as simple as that. They could have come up with another name for that fiber — like angora from rabbits, cashmere from goats, etc — but they didn't. It's called "camel hair" as in "a camel hair jacket."

That doesn't preclude you from using the possessive form for a camel's hair (as in "the camel's hair was long and matted). You simply have to know that the material that comes from a camel is commonly called "camel hair."

Incidentally, a sheep's wool literally refers to the wool of a sheep. You can also get wool from goats (commonly called cashmere or mohair), rabbits (angora)… and, yes, even camel hair is a type of wool. Saying sheep's wool is simply used to disambiguate it — and there's nothing wrong with referring to the material as "sheep wool".

Answer 2

I'm not aware of a rule about “if the separation of an animal’s part implies its death [then] the “_’s” is dropped, as in the case of calf skin”. If such a rule exists, it is not used consistently. For example, ngrams for elephant tusk,elephant's tusk shows similar counts (in recent years) for both terms, and the linked book references show similar usage (similar meanings) for both. Ngrams for cow horn,cow's horn is weighted slightly more in favor of the proposition, but in recent years both terms have been used with similar frequency. Note, elephants are killed for their tusks in most cases, but cow horns are obtained without killing the cow, in most cases.

In short, there are many exceptions to the “rule”, and the exceptions go both ways ― ie, 's being used for fatally-obtained items, or not being used for nonfatally-obtained items.

Regarding “Carlo’s heart” or “Carlo heart”, the latter phrase would not be used to refer to your heart in any way I'm aware of.

Answer 3

No. In the case where the 's is dropped, we are referring to the animal in it's mass noun form as an adjective of the object, for example:

Before it was made illegal, piano keys were often made out of elephant tusks.

In this case, elephant is an adjective to tusks meaning that the tusk in order to distinguish it from any other particular type of tusk, such as a walrus tusk.

When the 's is employed, we are referring to the tusk in the possessive sense, for example:

We went to see Nelly the elephant at the zoo. We were very impressed at the size of the elephant's tusks.

In this case, elephant's tusks is merely the tusks belonging to the elephant - in this case Nelly the elephant at the zoo.

Note that this is in no way related to the death or otherwise of the subject:

When we went to the zoo we were impressed by Nelly's tusks.

In the classroom we learned that elephant tusk is a very durable material.

Later we learnt that one of Nelly's relatives called Joey the elephant had been killed for his elephant tusks.

The poacher had been captured and the elephant's tusks were on display.

Answer 4

I think of it this way...

elephant's tusk

is when the tusk is still attached to the elephant. We would assume it's still alive, but not necessarily so. Its a possessive form.

elephant tusk

is the tusk after removal from the elephant. It's a modified noun. Since it has been removed, it's technically dead, regardless of the state of the elephant it came from.