Subject: Why is there no wavelength associated with a 1s2s-1s2 in He I para spectrum

I was looking at the spectrum of neutral Helium. Apparently Helium has two 
atomic states, which give rise to two non-mixable spectrums called the ortho 
and the para. In the para spectrum there is a sequence of transitions that 
involve the transition of electrons from the 1snp orbitals to the 1s2 ground 
state, which begins with the wavelength 584A. There is another which involves 
the transition of electrons from the 1snp orbitals to the 1s2s, n=2,3,4...- 
which begins with 20586A. The problem I have is that there is no wavelength 
associated with a 1s2s to 1s2 transition. I would assume that the shape of 
each is spherical, with the 2s being larger. 

  The reason I am looking at this in detail is because I am interested in the 
accepted electron configuration model, and how it explains Helium. I find the 
idea that excited electron states involving the p orbitals have a choice of 
which state to 'fall' into. It is disconcerting that these two should be 
disconnected, where in theory an electron which makes a transition to a 2s 
needs to go back up before it can fall to the ground state.

Perhaps,  I am confused between the concepts presented in Bohrian terms, and 
those that are now generally accepted. Your insight would be appreciated.

Thank you, Sean

Re: Why is there no wavelength associated with a 1s2s-1s2 in He I para spectrum