[link to original on tumblr]
---&---
The speaker/singer of "She's Coming Home" seems to be stationary, indicated by the line "She sent word to me" (which, admittedly, is in the chorus, rather than the bass-stationary verses), where the speaker/singer of "Care of Cell 44" is mobile, indicated by the line "Come up and fetch you, saved up for the train fare money." So he's actively involved in reuniting with his girl, where the speaker/singer of "She's Coming Home" is just sitting there, waiting for his girl to return to him. Both of these positions seem to be indicated by the fluidity - or lack thereof - of the accompanying bass parts.
The bass part in "Care of Cell 44" does just sit on a G note during the bridge ("We'll walk in a way we used to walk / And it could be so nice…"), but there it sort of mirrors the speaker/singer's wish to revive the frozen past. He's looking back nostalgically ("in a way we used to walk") and forward hypothetically, hence the future tense ("we'll walk") and the subjunctive case ("it could be so nice").
This nostalgia-accompanied-by-a-static-bass-note sort of appears (figuratively, of course) in the second verse of "She's Coming Home" too (the verse with chordal organ accompaniment). There's the nostalgia in the line "Our love was such a sweet and gentle thing," which is accompanied by the bass playing only E notes. Musically, the second verse isn't very different from the first - it has the same chords and bass part; it's just that the chords are played on organ and guitar rather than on piano, as in the first verse - so the nostalgia-accompanied-by-a-static-bass-note works better in "Care of Cell 44," where the static bass part occurs only during the part where the lyrics involve that nostalgia. That way, it's musically distinct.
After that part in "She's Coming Home," there's the line "I threw our love away without a thought," where the bass plays the recurring descending phrase in the song (E, D#, C#, B), sort of reflecting the throwing away mentioned in the line (it doesn't quite match up to the lyrics).
Most of the bass part in "Care of Cell 44" is also descending, but there are rapid ascending phrases after them (plus the recurring and mostly upward-moving phrase that - on piano - opens the song), almost to reflect the song as a whole: the sadness of the girl's going to prison and being separated from the speaker/singer followed by the joy of the anticipated reunion.
It's probably just that Rod Argent got better writing bass parts between the time of "She's Coming Home" and "Care of Cell 44" (they're two years apart - March 1965 & August 1967), but it has an interesting meaning when looked at without that real-world, behind-the-scenes factor.
Of course, there's also the (very likely) possibility that I'm just looking at this too closely and ascribing too much importance to certain musical elements.
Also, can I just draw attention to the line "Kiss and make up, and it will be so nice" in "Care of Cell 44"? I didn't pay much attention to it the first few hundred times I listened to the song (I usually pay attention to the music, not the lyrics), but it seems that the speaker/singer is in some way responsible for the girl's imprisonment.