These cases are presented primarily because of the rarity of the same anomaly affecting all children of a family.
The method by which we have arrived at an approximate diagnosis of the nature of the causative factor is presented as a preliminary report.
The three boys, Albert, 11, Theodor, 10, and David, 6 years of age, will in what follows be referred to as Cases 1, 2 and 3, respectively.
These boys, who came under observation two and one-half years ago, during an attack of whooping cough, and who have been under observation ever since, all show an excellent mental development and the two younger ones good physical development. The cyanosis of the skin and mucous membranes is constant and the latter is especially evident in the conjunctival and buccal mucous membranes and in the lips. Their cyanosis increases under various conditions, more especially during periods of excitement following physical