So endeth this chronicle.
chronicle
(記録)
[名]
a factual written account of important or historical events in the order of their occurrence
こうしてこの記録は終わる。
It being strictly a history of a boy, it must stop here;
strictly
(厳密に)
[副]
in a strict manner
stop
(終わる)
[動]
come to an end
これは厳密に少年の物語なので、ここで終わらなければならない。
the story could not go much further without becoming the history of a man.
go much further
(これ以上先に進む)
[動]
proceed or progress beyond a certain point
物語は、男の物語にならずにこれ以上先に進むことはできない。
When one writes a novel about grown people, he knows exactly where to stop—that is, with a marriage;
novel
(小説)
[名]
a fictitious prose narrative of book length, typically representing character and action with some degree of realism
grown people
(大人)
[名]
a person who is fully developed or mature
exactly
(正確に)
[副]
in a precise and accurate manner
stop
(終わらせる)
[動]
come to an end; cease to happen
marriage
(結婚)
[名]
the legally or formally recognized union of two people as partners in a personal relationship (historically and in some jurisdictions specifically a union between a man and a woman)
大人の小説を書く場合、どこで終わらせるか、つまり結婚で終わらせるかを正確に知っている。
but when he writes of juveniles, he must stop where he best can.
juvenile
(少年少女)
[名]
a young person
しかし、少年少女の小説を書く場合、できるだけ良いところで終わらせなければならない。