The Compendium of Caraka 6.2.4.4

6.2.4.4

dehasattvabalāpekṣī harṣaḥ śaktiśca harṣajā//
rasa ikṣau yathā dadhni sarpistailaṃ tile yathā/
sarvatrānugataṃ dehe śukraṃ saṃsparśane tathā//
tat strīpuruṣasaṃyoge ceṣṭāsaṃkalpapīḍanāt/
śukraṃ pracyavate sthānājjalamārdrāt paṭādiva//
harṣāttarṣāt saratvācca paicchilyādgauravādapi/
aṇupravaṇabhāvācca drutatvānmārutasya ca//
aṣṭābhya ebhyo hetubhyaḥ śukraṃ dehāt prasicyate/
carato viśvarūpasya rūpadravyaṃ yaducyate//
bahalaṃ madhuraṃ snigdhamavisraṃ guru picchilam/
śuklaṃ bahu ca yacchukraṃ phalavattadasaṃśayam//
yena nārīṣu sāmarthyaṃ &vājīvallabhate naraḥ/
vrajeccābhyadhikaṃ yena vājīkaraṇameva tat//
&`vājīva labhate' iti pā-.
yadā na sevyāḥ pramadāḥ kṛtsnaḥ śukraviniścayaḥ/
niruktaṃ ceha nirdiṣṭaṃ pumāñjātabalādike//

Excitement depends on the strength of the body and the mind, and capacity is born of excitement. / Just as juice is present throughout sugarcane, ghee in curds, and oil in sesamum, / so semen is present throughout the entire body in the sense of touch. / In the union of woman and man, through movement, intention, and pressure, / that semen slips from its place, like water from a wet cloth. / Through excitement, through yearning, through mobility, through sliminess, and through heaviness, / through subtle fluidity, and through the speed of the wind— / from these eight causes, semen is poured out from the body. / What is called the substance of form of that manifold [semen] as it moves: / thick, sweet, unctuous, not foul-smelling, heavy, slimy, / white, and abundant—that semen is fruitful beyond doubt. / That by which a man attains capability with women like a stallion, / and by which he approaches them with great vigor, is indeed virilisation. / When women are not to be approached, the entire determination of semen, / and its definition are set forth here in [the section] beginning with "When a Man Has Gained Strength".