The growth in the seedling stage of Raphanus sativus L. var. raphanistroides Makino, variety "Minowase", which is highly sensitive to vernalization, was studied. The changes in external form and dry matter weight of the seedling under a heterotrophic and a autotrophic conditions were investigated. Under a heterotrophic condition, the plant grew larger, but there was little change in dry matter weight of the plant a week after germination. This stage is termed the seedling stage and it marks the course of eight days after germination. The seedling stage is divided into three stages. The first stage is from 1 to 2 days after germination, in which stage no considerable changes arise, but it is conceivable that the catabolism is proceeding in cotyledons providing for the movement of nutritions substances. The second stage is from 3 to 5 days after germination, and at this stage dry matter of cotyledon decreases strikingly, on the contrary that of hypocotyl increases suddenly. The third stage is from 6 to 8 days after germination, and at this stage the decreasing of dry matter of hypocotyl decreases and the increasing of that of cotyledon petiole begins. Under a heterotrophic condition, only dry matter weight of cotyledon which is the reserve organ decrease, while those of all the other organs of the seedling increase. Under a autotrophic condition, as under the heterotrophic condition, dry matter weight of cotyledon decreases, while that of the seedling increases gradually, till about the middle of the second stage. However, dry matter weight of cotyledon does not decrease suddenly as under the heterotrophic condition. Under a autotrophic condition as well as under a heterotrophic condition, the remarkable change of the variation of dry matter weight in each mutual organ was observed in the second stage, and from the middle of this stage plumule began to grow. Under this condition, the change of dry matter weight in each organ became different from that under the heterotrophic condition in the second stage in which remarkable changes were observed. It is thought that the plant began to grow on the autotrophic pattern in this stage. As compared with the changes of dry matter weight under weight under the heterotrophic condition, the increasing of dry matter weight was observed in all the organ under the autotrophic condition, and it was most remarkable in cotyledon, second in cotyledon petiole, but it was little in radicle. The rate of increasing of dry matter weight in each organ which arose with the change of nutritive type in the seedling stage is striking in cotyledon, and it is thought that the remarkable feature brought by the change of nutritive type in the seedling stage is the increase of dry matter weight in cotyledon. It is thought that remarkable difference in the two nutritive types consist in the action of cotyledon in which catabolism is predominant as reserve organ under the heterotrophic condition, but anabolism is predominant as synthetic organ under the autotrophic condition.