Per arctam viam Hercules incēdēbat; in quā cum aliquid malō simile humī positum vīdisset, omnī vī diffringere cōnābātur. Sed cum illud dūplō māius factum animadverteret, māiōrī nīsū īnstitit, et clāvā atterere studēbat. At mīrum, arbor illa repente in immānem magnitūdinem excrēvit, tōtamque viam obstruxit. Quapropter clāvā abiectā, mīrā reī novitāte perculsus ac stupefactus restitit. Sed Minerva illī appārēns, Dēsine, ait, mīrārī, frater; quod enim vidēs, contentio et līs est; quae quidem, sī quis sine pugnā relīquerit, nullīus mōmentī sunt, at contrā sī lacessīverit, magis magisque crescunt.
SOURCE: This comes from the Latin translation that accompanies De Furia's edition of the Greek Aesopic corpus, published in 1810 and available at GoogleBooks. This is fable 419 in De Furia; for other versions, see Perry 316.
READ OUT LOUD. Choose which marked text you prefer to practice with - macrons (above) or accent marks (below) - and read the text out loud until you feel comfortable and confident. Then, try reading the unmarked text at the very bottom. It should be easy for you after practicing with the marked texts. :-)
ACCENT MARKS. Here is the text with accent marks, plus some color-coding for the words of three or more syllables (blue: penultimate stress; red: antepenultimate stress):
Per arctam viam Hércules incedébat; in qua cum áliquid malo símile humi pósitum vidísset, omni vi diffríngere conabátur. Sed cum illud duplo maius factum animadvérteret, maióri nisu ínstitit, et clava attérere studébat. At mirum, arbor illa repénte in immánem magnitúdinem excrévit, totámque viam obstrúxit. Quaprópter clava abiécta, mira rei novitáte percúlsus ac stupefáctus réstitit. Sed Minérva illi appárens, Désine, ait, mirári, frater; quod enim vides, conténtio et lis est; quae quidem, si quis sine pugna relíquerit, nullíus moménti sunt, at contra si lacessíverit, magis magísque crescunt.
UNMARKED TEXT. Here is the unmarked text - after practicing with the marked text that you prefer, you should not have any trouble with the unmarked text:
Per arctam viam
Hercules incedebat;
in qua
cum aliquid
malo simile
humi positum vidisset,
omni vi
diffringere conabatur.
Sed cum illud
duplo maius factum
animadverteret,
maiori nisu institit,
et clava atterere studebat.
At mirum,
arbor illa
repente
in immanem magnitudinem
excrevit,
totamque viam obstruxit.
Quapropter
clava abiecta,
mira rei novitate
perculsus ac stupefactus
restitit.
Sed Minerva
illi apparens,
Desine, ait, mirari, frater;
quod enim vides,
contentio et lis est;
quae quidem,
si quis
sine pugna reliquerit,
nullius momenti sunt,
at contra
si lacessiverit,
magis magisque crescunt.
IMAGE. Here is an illustration for the story (image source); it's a Greek vase painting showing both Hercules and Minerva, a.k.a. Heracles and Athena:
