TUYMVH AM) o'lHEIi DUCTLESS GLAyDS 617 



rotentioii results fidiii feeding' tliviiius, Iml the ri'sulls (|iintc(l ari' not at all in liar- 

 mony. It is certain, liowovcr, tiiat (h'lici(>n<-y in tlie tliynuis causes a defect in 

 ossification. Also llierc occurs a period of adiposity, followed hy cacliexia witli 

 liyperplasia of tiic lynijihatic tissues, thyroid, pancreas, ovaries and testicles 

 ( Klose and \'o','t ) . These authors attrilnite the defects in ossification to aii 

 acidosis, which liypothesis is, liowever. far from established. ( ludernatscli 27 

 found that the fecdin<r of tliymus to tadpoles causes a great increase in the rate 

 of growth, and decreases or suppresses the develoj)mental changes, liaving exactly 

 the opposite efTect from tliyroid feeding, and Abderhalden 2Ta liag found that this 

 property persists after digesti(m of tlie thymus tissue. As yet no substance has 

 been isolated which can be considered as a sjjccific internal secretion of the 

 thymus, altliougli the frc<|uent conciu-rence of abnornuil conditions in the thyroid 

 and thymus, in the adi^cnals and thymus, in the hypophysis and thymus, to- 

 gether with tlie frei|uency of ])olyglaii(lular conditions, leaves no (|ucstion that the 

 thymus is to be considered with tlic other members of this system, however differ- 

 ent its histological structure may be.^Tb Thymus administration by mouth does not 

 counteract the loss of the thymus. The enlargement of tlie thymus that occurs in 

 most cases of exophthalmic goiter is accompanied at times by symptoms that 

 suggest an intoxication from this source.27c 



The chemistry of tlio Pinfal Glaxd can be dismissed practically without con- 

 sideration, since no positive facts have lieen brouffht to light. Extracts from the 

 organ show no distinct physiological eflfects.^s Tumors of the pineal gland have 

 been found associated witli adiposity and witli precocious sexual devel<i])nient, but 

 whether from the action of the gland itself or from the pressure on the brain, 

 cannot be said. 29 Extirpation of the pineal seems to have no noticable effects of 

 any sort (Dandy 2na) although ^IcCord 29b reports increased growth and early 

 sexual maturity in animals fed pineal substance. 29c 



The Carotid Glaxd is more directly related to the adrenal medulla, in that it 

 contains chromaffin tissue. It should, presumably, contain a pressor principle, as 

 Moulon found, l>ut Gomez 30 obtained only lowering of blood pressure fi-om extracts 

 of this gland, and bilateral removal causes no characteristic effects.soa 



2T Arch. Entwicklgs., ini2 (35), 457: Amer. Jour. Anat., 1914 (15), 431. 



27a Arch. ges. Physiol., 1915 (162), 99. 



27b Literature given by Basch, Zeit. exp. Path., 1913 (12), 180. 



270 See review by Halsted, Bull. Johns Hopkins Hosp., 1914 (25), 223. 



28 Jordan and Eyster, Amer. Jour. Physiol., 1911 (29), 115: Dixon and Halli- 

 burton, Quart. Jour. Exper. Phvsiol., 1909 (2), 283. Dana and Berkelev. Med 

 Record, 1913 (S3), Xo. 19. 



29 See Pappenheimer, Virchow's Arch., 1910 (200), 122. 

 29a Jour. Exp. :Med., 1915 (22), 237. 



29b Jour. Amer. Med. Assoc, 1914 (63), 232 and 517. 



29c Concerning the composition of the pineal gland see Fenger, Jour. Amer. ^led 

 Assoc. 1916 (67), 1836. 



30 Amer. Jour. IVIed. Sci., Julv, 1908. 



30a Massaglia, Frankf. Zeit. Path., 1916 (18), 333. 



