On the first sonnet, Boswell pointed out,
See Venus and Adonis:
 Upon the earth's increase, why should'st thou feed,
Unless the earth with thy increase be fed,
By lay (sic) of nature thou art bound to breed,
That thine may live when thou thyself art dead;
And so in spite of death thou dost survive,
In that thy likeness still is left alive.'1
If the first nineteen Sonnets be attentively examined, they will be found only to expand the argument of that stanza. I have been tempted frequently to consider those, and many more of the collection, as parts of the design to treat the subject of Adonis in the sonnet form; relinquished by the poet for the present more manageable stanza.2
It seems clear, however, that this series of seventeen sonnets-- or nineteen if one prefers--or more correctly still, twenty--was written later than the passage in Venus and Adonis. As we have seen, these arguments in Venus and Adonis are an interpretation of the source story in Ovid. It is likely, therefore, that they are the original. Besides, as Boaden indicates, the sonnets are an expansion of the argument in Venus and Adonis. We should add to the stanza quoted, however, the two preceding stanzas of Venus and Adonis.
 Is thine own heart to thine own face affected?
Can thy right hand seize love upon thy left?
Then woo thyself, be of thyself rejected,
Steal thine own freedom and complain on theft.
Narcissus so himself himself forsook,
And died to kiss his shadow in the brook.