Abstract
Following recent studies of the sphincters occurring in the arteries of the thyroid glands of some rodents, the author made some additional observations on those of the guinea pig, im comparison with other peculiar structures reported as the intima thickening and arterial bud.
The author obtained a result almost similar to S u g i y am a's and reached the same conclusion concerning its significance. The author wishes to express his appreciation to Prof. H. Nag ama tsu for his kind and continued guidance and criticism during this study, to Prof. Ch. Togari for his kind advice and for supplying some of the materials used in this study, and to Prof. S. Sugiya ma, Nagoya City University Medical School, for his helpful suggestions in the preparation of the manuscript.
