Though assent must be expressed in order to be legally effective, it need not be expressed in words. In the early law of assumpsit stress was laid on the necessity of a promise in terms, but the modern law rightly construes both acts and words as having the meaning which a reasonable person present would put upon them in view of the surrounding circumstances.3 Even where words are used "a contract includes not only what the parties said, but also what is necessarily to be implied from what they said." 4 And it may be said broadly that any conduct of one party, from which the other may reasonably draw the inference of a promise, is effective in law as such. Thus if A steps into his grocer's, and takes a package of goods from the counter, hands it to a clerk, and walks out, his conduct may mean, "if you will send that package to my house I will pay for it;" and the subsequent act of the clerk in sending the package, though no words have been spoken, amounts to an acceptance.