At the present state of our knowledge it is difficult to assign to the ductless glands their proper place in the animal economy, or to tell what part they play in the elaboration or neutralization of auto-toxins. There can be no doubt but that they are intimately concerned in the bio-chemistry of the body, for changes in their functional powers are followed by profound tissue changes. Their internal exhibition as medicine and experimental poisonings show that they contain powerful active principles producing phenomena of a constant nature.

Blum (54) considers that the prime function of the thyroid is to destroy the poisons which circulate in the blood and which are derived chiefly from the intestinal canal. These entero-toxins are arrested in their passage through the gland, are deposited there as thyreo-toxalbumin and are gradually rendered harmless. Now if the activity of the thyroid is in any way impaired, and the entero-toxins circulate unhindered, accumulation and consequently intoxication take place.

In a series of important experiments Breisacher (55) has shown that the extirpation of the thyroid in animals is not necessarily fatal, and that in animals so treated a milk diet is much more favorable to life than meat. This not only throws light on the dietary treatment of myxedema, but also suggests that the thyroids are of great importance in the oxidation of purins, of which milk contains none and meat 15 to 20, grains per pound.

That the thyroid has special power in neutralizing toxics is shown by the experiments of Remedi (56) who injected diphtheria toxin and bacteria nucleo-proteids into the substance of the thyroid, and, although the secretion of the gland was temporarily increased, there was no inflammation or necrosis such as inevitably follows the injection of these substances into other tissues.

The chief diseases into which intoxication resulting from diminished or excessive secretion of the ductless glands enters are exopthalmic goitre, myxedema, including cretinism, and Addison's Disease. In myxedema and exopthalmic goitre we have two states due to opposite conditions of the thyroid; the former due to decrease and the latter to increase in its functional activity. Horsley, Kocher and Riverdin produced conditions closely analagous to myxedema by the removal of the thyroids of animals, and the symptoms of goitre may be produced at will by the experimental administration of thyroid substance or its extracts. That lack of functionally active thyroids and parathyroids is the prime cause of myxedema and cretinism is apparent from the abundant testimony of relief of the disease when thyroids are given as medicine. And the aggravation of many cases of exopthalmic goitre when thyroids are administered shows that they only increase the amount of poison already in the system.

Mosse offers the theory that the Adrenals have two functions, one, the production of a physiological substance of a stimulating nature, the other, the neutralization of poisons formed in various parts of the body.

In this disease both of these functions are impaired by the atrophy or calcification of the adrenals, and the auto-toxins are appropriated by the spleen, extracts of which are toxic to mice, (57).

This secretion which is supposed to control and govern blood oxidation is called by Sajous adrenoxin and the general symptoms of any poison circulating in the blood is to be considered as due to the disordered function of the ductless gland system.

Poehl claims that the ferment which regulates oxidation processes is spermin, a base found in the pancreas, thyroid, testicles and the adrenals.

The function of the pituitary body is still sub judice, and experiments seem to show that it is in some way concerned in the phenomena of nutrition and toxemia. Its obliteration in dogs and cats is promptly followed by slowing of the respiration, acceleration of the pulse, mental depression and motor disturbances, arching of the back and spasticity of the gait without contractions of the limbs: progressive cachexia then occurs, followed by death in coma. This is interpreted as showing that the hypothesis is concerned in destroying or neutralizing auto-toxins. Cyon has corroborated these experiments and considers that disease of the pituitary is the cause of acromegaly. Lomonaco and Rymberk do not agree in these findings and claim that the results obtained are due to surgical shock, and infection or injury to tissues adjacent to the body and necessary to the operation itself.

In a case where fracture of the inferior maxilla produced jaundice, high temperature and blood disintegration, Wasdin (58) found the pituitary to be gangrenous, and from an investigation of the subject he concludes that this body acts through the cervico-sympathetic system upon the secretion of the adrenals, the normal function of which is to prevent hemolysis.