SPLITTING FRONDS ON DRYOPTERIS FILIX-MAS 'EUCHINENSIS'

While mooching around my little garden this morning I noticed something odd.  The Dryopteris filix-mas 'Euchinensis' has many fronds which are splitting at the ends in a fan-like way.  Looking at old photos, I see it has done it before but not so noticeably.  I have no idea why it is doing this but the plant seems to be very healthy.  Perhaps it is healthy and happy. 
Dryopteris filix-mas 'Euxinensis' with ends of fronds splitting
The fascinating sex life of ferns


Dryopteris filix-mas 'Euxinensis' with ends of fronds splitting
Looking at the photographs below, you can see that not only the very tips of the fronds are splitting but this is also happening at the end of each blade. 


Dryopteris filix-mas 'Euxinensis' with ends of fronds splitting


Dryopteris filix-mas 'Euxinensis' with ends of fronds splitting
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