[The content of the DNA, the RNA and the wet weight and the RNA:DNA and the wet weight:DNA ratio in different tissues during the growth of chickens. 2. Analysis of the kidney, the spleen, the gizzard and the M. pectoralis superficialis].

At chicken of the race "White Leghorn" the content of nuclei in the kidney was highest (14.60 x 10(9)) on the 203rd, in the spleen on the 112th (14.85 x 10(9)), in the gizzard on the 112th (18,24 x 10(9)) and in the M. pectoralis superficialis on the 168th day (36.42 x 10(9)) after hatching. The biggest fresh weight:DNA-ratio was determined in the kidney on the 203rd (285), in the spleen on the 28th (92) and in the gizzard (694) and in the M. pectoralis superficialis (1984) on the 203rd day. The DNA-concentration on the 2nd day after hatching in the kidney was 4,56 +/- 0,36, in the spleen 11.49 +/- 0.84, in the gizzard 1.85 +/- 0.13 and in the M. pectoralis superficialis 2.96 +/- 0.18 mg/g wet weight respectively the RNA:DNA-ratio in these tissues 1.00, 0.88, 1.70 and 0.85. The growth of tissues by the increase of the number of cells (hyperplasia) and of the volume of cells (hypertrophy) is described.