TABLE 3.

Distribution of [³H]Rna in Ribosomal Fractions of S. purpuratus late embryos^a

Expt	Stageb	Percentage inhibition with emetine	Number of transits in emetine	Percentage [3H]RNA
					Polyribosomes
				Monoribosomes	Small	Large
1.	HatchingBlc	Control (2)	-	42.5±0.3	26.4 ± 0.3	31.1 ± 0.6
	Hatching Blc	60	1.5	34.4	27.9	37.6
2	BlMy-1-2d	Control	-	49.3	20.7	30.0
	BlMy-1-2d	72	1.05	31.4	22.8	45.8
3.	BlMy-1e	Control (2)	-	54.2 ± 0.1	18.9 ± 0.2	26.9 ± 0.2
	BlMy-2/Ga-1f	Control	-	58.2 ± 0.6	18.5 ± 0.5	23.3 ± 0.1
	BlMy-2f	76	1.8	38.2	24.4	37.4
4.	Prismg	Control (4)	-	64.0 ± 1.7	20.6 ± 0.8	15.5 ± 1.5
	Prismg	77 (2)	0.86/1.72	37.3 ± 1.0	27.5 ± 2.2	35.2 ± 1.2

^aConditions as in Table 1.

^bFor nomenclature of stages see Whiteley and Baltzer (1958). The culture times at 14°C at which polyribosome profiles were measured are:

^c16–18 hr,

^d23–24 hr,

^e24.5 hr,

^f27.5 hr,

^g48–52 hr.