It has been assumed that the sea-rockets, Cakile Mill., are adapted to life on the beach. It is here suggested that the habit of the plants, their annual cycle, the structure of the fruit and the consequent distribution by the sea cannot be regarded as typical, special adaptations to the sandy beach. In view of the only moderate resistance to salinity, the rather large requirements of nitrogen, fresh water and light the sea-rockets should be regarded as plants of the more nutritive parts of open, sandy habitats with sparse vegetation and sufficient supply of fresh water. These conditions are offered by the beach, whereby the plants can grow there, using capacities more commonly encountered among their prairie and desert relatives, while making use of the sea for its distribution through structures that have not been especially developed for this purpose.