This is what Hassan says, "The three sub-castes, Deshasthas, Konkanasthas and 
Karhadas, were formerly strictly endogamous  but with the spread 
of western education this rigidity of the caste bond is being slackened, 
and instances of intermarriages between their members are of frequent 
occurrence at the present day". When he says present day, he is talking about 1920 or thereabout when the book was published!

Obviously, you are not looking hard, are you ? If you want to stop the edit war on this, keep checking. You have access to the book. 74.9.96.122