Masti here is describing the characteristics of a new born baby. Going through the 3 things which he uses to describe:
milk stains on one side of her face and
This refers to the milk stains on the cheek caused due to either spilt milk on their cheeks while feeding or because the baby has pushed back the milk from their mouth causing it to spill over on the cheeks. This is quite characteristic of a new born baby who still hasn't learned the art of drinking milk.
wetness on the other
This can refer to
1. saliva: Babies drool starting from when they are born to when they are a few months old. This scene is descriptive of a new born kid drooling causing the saliva to spill on the other cheek.
2. tears: Babies do tend to cry a lot, there fore the scene is describing wet tears dropping on the other cheek. (However, given that very new born babies don't cry with tears, this might not be the case).
so young that she doesn't even know how to bite her fingers?"
Now coming to the crux of the question, not knowing how to bite her fingers is a depiction of babies who are less than 3 months old. At the age of 3 months, babies start to grow teeth, and the first thoughts are to suck the thumb, bite the fingers and so on. Therefore not being able to bite their own fingers is a depiction of a very small (neo-natal) baby.
(I guess this is common amongst babies in the entire world)
Therefore, by using those three adjectives, Masti has painted a beautiful picture, where you can imagine the character wedding a new born infant.
The depiction of small children sucking their thumbs or biting their thumbs to describe their innocence is quite common across the various cultures in India. (This is a question which I've asked on Hinduism Stack Exchange site about a related description). Similarly, the phrase like "Milk drinking child" is commonly used to describe infants who have not been consuming solid food. Both of these, when used against a grown up person, tends to talk about the innocence of that person if it is used in a positive manner, or the immaturity, if it is used in a negative manner. A couple of examples can be:
- "Look at her, she can't tell the difference between what is bad and what is good. She is still a milk drinking child" : this is talking about her being innocent.
- "Look at him, he can't tie his own shoelaces. He is still a milk drinking child" : this is talking about him being immature.
In this particular paragraph, Masti is talking about the innocence aspect.
Looking at the bigger picture, the character here (Rangappa) is refusing to marry someone who is very young compared to him. He does exaggerate a bit when he describes a younger girl as an infant, but the imagery used by the author is very appealing if you read it in the original language.
In the story, Rangappa also describes his feelings:
"I need to find the right girl. I know an officer who got married only six months ago. He is about thirty and his wife is twenty -five, I am told. They will be able to talk lovingly to each other. Let's say I married a very young girl. She may take my words spoken in love as words spoken in anger. Recently, a troupe in Bangalore staged the play Shakuntala. There is no question of Dushyantha falling in love with Shakuntala if she were young, like the present-day brides, is there? What would have happened to Kalidasa's play? If one gets married, it should be to a girl who is mature. Otherwise, one should remain a bachelor. That's why I am not marrying now."
You can grasp the primary aspect here. He is making it clear that a girl should get married only when she is able to understand the feelings of love. A young girl (the one who is not even able to bite her fingers) would certainly have no ability to comprehend the difference between love and anger. He cites an old mythological story as an example for how he feels that marriages should be.
The historical perspective is also important here. Masti was from the "Navodaya" age of Kannada literature, where the authors focused more on social aspects rather than discussions about rulers. Child marriages were common in the middle ages (especially during the Mughal rule and the subsequent Sultanates). It had extended into Colonial India as well, but there were a lot of reformers who were trying to advocate the evils of these. This short story by Masti, was one amongst the several in his book "Kelavu Sanna Kathegalu" which was trying to talk about the evils of child marriage, and how "mature" and people "with manners" (hinting about educating children here) should not be indulging in these.
