MR. SIMON ON THE COMPARATIVE ANATOMY OF THE THYROID GLAND. 303 
intention of its vascular supply; as the latter is diverticular, so we may expect the 
former to be vicarious, or alternative. 
Such are the conclusions which Comparative Anatomy may warrant, and beyond 
these the proposed scope of the present paper does not permit me to advance. I 
would but in ending- remark, that the views here suggested seem to me to receive 
equal sanction when contemplated in the light of the other physiological sciences. 
The peculiarly occasional and intermitting character of the cerebral functions, — the 
morphology of the thyroid gland, and its evident adaptation (as I have elsewhere shown) 
for a merely temporary, and, as it were, alternative secretion, — the known ability of 
arteries to regulate and proportion the supply of blood transmitted through them, — 
the diseases of the gland, — its turgid throbbing in hysterical lipothymia, — the my- 
sterious relation of goitre and cretinism ; — these are topics on which it would be 
inconvenient now to dwell, but a glance at which is sufficient to show that compa- 
rative anatomy by no means exhausts the available arguments for the connexion 
suggested. 
2 R 
MDCCCXLIV. 
