A centrifuge for selectively concentrating and collecting constituents of a biologic liquid mixture, said constituents having differing specific gravities and being stratifiable in a centrifugal field produced by said centrifuge, said centrifuge comprising: a. a chamber arranged to contain a liquid mixture and having a central longitudinal axis about which said chamber is arranged to be rotated to produce said centrifugal field, said chamber comprising: i. an assembly comprising a tubular barrel and an end wall, each comprising a common central longitudinal axis, said tubular barrel comprising a side wall tapering radially inward toward said central longitudinal axis from said end wall; ii. an inlet for adding the liquid mixture to said chamber; iii. a first port in fluid communication with said chamber and located in said assembly at a first radial distance from said central longitudinal axis; and iv. a circumferential channel extending from the interior of said barrel to said first port, said circumferential channel comprises a restricted portion and a non-restricted portion, said restricted portion comprising a restriction in a least a portion of said circumferential channel; and b. a motor to rotate said chamber about said central longitudinal axis to produce said centrifugal field, whereupon said constituents of said biologic liquid mixture in said chamber stratify into at least two concentric stratified constituent layers as a function of the differing specific gravities of said constituents, wherein a first of said at least two concentric stratified constituent layers is present at said first port, said first port being selectively openable to enable at least a portion of said first of said at least two concentric stratified constituent layers in said chamber to be automatically ejected from said chamber through said first port as a result of pressure built up by said centrifugal field, said circumferential channel being adapted to reduce the velocity of the flow of said at least a portion of said first of said at least two concentric stratified constituent layers at the point of entry into said circumferential channel relative to the velocity of said at least a portion of said first of said at least two concentric stratified constituent layers ejected through said first port, with said restricted portion of said circumferential channel being adapted to at least partially restrict the flow of at least a portion of said first of said at least two concentric stratified constituent layers in said circumferential channel. a. a chamber arranged to contain a liquid mixture and having a central longitudinal axis about which said chamber is arranged to be rotated to produce said centrifugal field, said chamber comprising: i. an assembly comprising a tubular barrel and an end wall, each comprising a common central longitudinal axis, said tubular barrel comprising a side wall tapering radially inward toward said central longitudinal axis from said end wall; ii. an inlet for adding the liquid mixture to said chamber; iii. a first port in fluid communication with said chamber and located in said assembly at a first radial distance from said central longitudinal axis; and iv. a circumferential channel extending from the interior of said barrel to said first port, said circumferential channel comprises a restricted portion and a non-restricted portion, said restricted portion comprising a restriction in a least a portion of said circumferential channel; and i. an assembly comprising a tubular barrel and an end wall, each comprising a common central longitudinal axis, said tubular barrel comprising a side wall tapering radially inward toward said central longitudinal axis from said end wall; ii. an inlet for adding the liquid mixture to said chamber; iii. a first port in fluid communication with said chamber and located in said assembly at a first radial distance from said central longitudinal axis; and iv. a circumferential channel extending from the interior of said barrel to said first port, said circumferential channel comprises a restricted portion and a non-restricted portion, said restricted portion comprising a restriction in a least a portion of said circumferential channel; and b. a motor to rotate said chamber about said central longitudinal axis to produce said centrifugal field, whereupon said constituents of said biologic liquid mixture in said chamber stratify into at least two concentric stratified constituent layers as a function of the differing specific gravities of said constituents, wherein a first of said at least two concentric stratified constituent layers is present at said first port, said first port being selectively openable to enable at least a portion of said first of said at least two concentric stratified constituent layers in said chamber to be automatically ejected from said chamber through said first port as a result of pressure built up by said centrifugal field, said circumferential channel being adapted to reduce the velocity of the flow of said at least a portion of said first of said at least two concentric stratified constituent layers at the point of entry into said circumferential channel relative to the velocity of said at least a portion of said first of said at least two concentric stratified constituent layers ejected through said first port, with said restricted portion of said circumferential channel being adapted to at least partially restrict the flow of at least a portion of said first of said at least two concentric stratified constituent layers in said circumferential channel.