The thing I found most curious about this picture is that back in the 40's, 
people usually only took pictures of their pets for one of 2 reasons:
1) Because the pet was something really special to their heart
2) To finish a roll of film so they could take it for developing

I'm betting that Dad took this picture of Jack because he really was 
a good dog.  Jack is in several of the pictures with our kin.

I thought it was pretty neat to discover that Dad's favorite dog's face has a slightly curious
resemblance to a polka-dotted 'boston terrier, beagle & fiest mix' 
that moved into my home and took over our life.

I wish that Dad could be here to teach me how to train my Penny Puppy
to be as well mannered as his dogs always were...
Dad had that 'gift' with animals and it was remarkable how he won them over 
and had them literally trained without ever raising a hand against them.
I think Dad would have had a interesting time trying to train Penny Puppy...