What's the difference between hereunto and whereinto?

Hereunto

Definition:

• (adv.) Unto this; up to this time; hereto.

Example Sentences:

• (1) In token whereof I have hereunto set my hand this tenth day of December, 1936, in the presence of the witnesses whose signatures are subscribed.

Whereinto

Definition:

• (adv.) Into which; -- used relatively.
• (adv.) Into what; -- used interrogatively.

Example Sentences: