Table 1.

P. vivax densities in continuous culture at 10–12 hr after the addition of reticulocytes

Cycle	Subcultures	Hours in culture	Dilution of monkey to human blood	Mean no. of parasites in 104 cells (n = 3)	SE
Culture 593
1	Primary	0	1:0	14.00	1.15
2	a	48	1:1	15.67	2.03
3	a*	97	1:2	28.00	2.52
4	b	145	1:4	42.00	3.61
	c*	145	1:4	33.00	1.53
5	b†	194	1:8	28.00	1.73
	d	194	1:8	28.00	1.73
	e	194	1:8	34.33	2.03
6	d*	242	1:16	34.67	4.91
	e‡	242	1:16	25.67	1.67
7	f	291	1:32	32.00	1.00
	g†	291	1:32	32.67	0.33
8	f†	339	1:64	33.00	0.58
Culture 194
1	Primary	0	1:0	21.67	1.20
2	a	51	1:1	43.00	3.00
3	a*	99	1:2	46.00	2.65
4	b	147	1:4	44.67	1.67
	c	147	1:4	54.67	2.03
5	b	195	1:8	56.67	1.86
	c†	195	1:8	50.33	0.88
6	b†	245	1:16	55.00	3.06

The primary cultures from an owl monkey were passaged to human reticulocytes beginning the first subculture (a) or the second generation of parasites. 

^*As reticulocytes were added and the volume of parasitized cells increased, subcultures were divided at the beginning of some cycles and were named alphabetically. 

^†Subculture was removed and cryopreserved. 

^‡Subculture was removed and injected into monkey.