Our story of "Juan and his Adventures" belongs to the "Animal Brothers-in-Law" cycle, a formula for which Von Hahn (1 : 53) enumerates the following incidents:--
A Three princes who have been transformed into animals marry the sisters of the hero.
B The hero visits his three brothers-in-law.
As Crane says (p. 60), this formula varies, of course. Sometimes there are but two sisters (cf. our variant), and the brothers-in-law are freed from their enchantment in some other way than by the hero. For a bibliography of this group, see Crane, 342-343, note 23, to No. 13.
Perhaps the best version of this story is that found in Basile, 4 : 3, the argument of which, as given in Burton's translation (2 : 372), runs thus:--
Ciancola, son of the King of Verde-colle, fareth to seek his three sisters, married one with a falcon, another with a stag, and the other with a dolphin; after long journeying he findeth them, and on his return homewards he cometh upon the daughter of a king, who is held prisoner by a dragon within a tower, and calling by signs which had been given him by the falcon, stag, and dolphin, all three came before him ready to help him, and with their aid he slayeth the dragon, and setteth free the princess, whom he weddeth, and together they return to his realm.
This argument does not quite do justice to the similarities between Basile's story and ours. For instance, in the Italian story, when the daughters leave, they give their mother three identical rings as tokens. Then a son is born to the queen. When he is fifteen years old, he sets out to look for his sisters, taking the rings with him. Nor, again, does this argument mention the fact that in the end the animal brothers-in-law are transformed into men,--a feature which is found in Basile, but not in our story. In the main, however, it will be seen that the two are very close. In Von Hahn, No. 25, the brothers-in-law are a lion, a tiger, and an eagle.
The opening of our story, so far as I know, is not found in any of the other members of this cycle. Usually the sisters are married to the animals in consequence of a king's decision to give his daughters to the first three persons who pass by his palace after a certain hour (Crane, No. XIII); or else the animals present themselves as suitors after the death of the king, who has charged his sons to see that their sisters are married (Von Hahn, No. 25; compare the opening of Wratislaw No. XLI = Wuk, No. 17). In our story, however, Pedro is deprived of his daughters in consequence of his greed. With this situation compare the "Maha-vanija-jataka," No. 493, which tells how some merchants find a magic banyan-tree. From this tree the merchants receive wonderful gifts; but they are insatiable, and finally plan to cut it down to see if there is not large treasure at the roots. The guardian-spirit of the tree, the serpent-king, punishes them. It is not impossible that some such parable as this lies behind the introduction to our story. There is abundant testimony from early travellers in the Islands that the natives in certain sections regarded trees as sacred, and could not be hired to cut them down for fear of offending the resident-spirit. The three handkerchiefs which the sisters leave with their mother as mementos are to be compared with the three rings in Basile's version. In a Serbian story belonging to this cycle (Wuk, No. 5), the three sisters are blown away by a strong wind (cf. our story of "Alberto and the Monsters," No. 39), and fall into the power of three dragons. When the brother, yet unborn at the time of their disappearance, reaches his eighteenth year, he sets out to seek his sisters, taking with him a handkerchief of each.