. "In composition, the b remains unchanged before vowels and before b , d , j , l , n , s , t , v. Before m and r it is frequently, and before the remaining consonants, c , f , g , p , it is regularly assimilated. Yet here the MSS. vary, as in ob , ad , in , etc. Before some words commencing with c. p , t , it assumes the form sus , by the rejection of the b from a collateral form subs (analog. to abs); e. g. suscipio, suscito, suspendo, sustineo, sustuli, sustollo. Before s , with a following consonant, there remains merely su" . "In composition, the b remains unchanged before vowels and before b , d , j , l , n , s , t , v. Before m and r it is frequently, and before the remaining consonants, c , f , g , p , it is regularly assimilated. Yet here the MSS. vary, as in ob , ad , in , etc. Before some words commencing with c. p , t , it assumes the form sus , by the rejection of the b from a collateral form subs (analog. to abs); e. g. suscipio, suscito, suspendo, sustineo, sustuli, sustollo. Before s , with a following consonant, there remains merely su" . .