The total quantity of blood is raised. While increased in quantity, the blood appears on the whole to be somewhat depreciated in quality, though on this point there are considerable differences of opinion. Thus, as regards hæmoglobin, some investigators have found that the old idea as to the poverty of hæmoglobin in pregnancy is quite unfounded; a few have even found that the hæmoglobin is increased. Most authorities have found the red cells diminished, though some only slightly, while the white cells, and also the fibrin, are increased. But toward the end of pregnancy there is a tendency, perhaps due to the establishment of compensation, for the blood to revert to the normal condition.[177] It would appear probable, however, that the vascular phenomena of pregnancy are not altogether so simple as the above statement would imply. The activity of various glands at this time--well illustrated by the marked salivation which sometimes occurs--indicates that other modifying forces are at work, and it has been suggested that the changes in the maternal circulation during pregnancy may best be explained by the theory that there are two opposing kinds of secretion poured into the blood in unusual degree during pregnancy: one contracting the vessels, the other dilating them, one or the other sometimes gaining the upper hand. Suprarenal extract, when administered, has a vaso-constricting influence, and thyroid extract a vasodilating influence; it may be surmised that within the body these glands perform similar functions.[178] The important part played by the thyroid gland is indicated by its marked activity at the very beginning of pregnancy. We may probably associate the general tendency to vasodilatation during early pregnancy with the tendency to goitre; Freund found an increase of the thyroid in 45 per cent. of 50 cases. The thyroid belongs to the same class of ductless glands as the ovary, and, as Bland Sutton and others have insisted, the analogies between the thyroid and the ovary are very numerous and significant. It may be added that in recent years Armand Gautier has noted the importance of the thyroid in elaborating nucleo-proteids containing arsenic and iodine, which are poured into the circulation during menstruation and pregnancy. The whole metabolism of the body is indeed affected, and during the latter part of pregnancy study of the ingesta and egesta has shown that a storage of nitrogen and even of water is taking place.[179] The woman, as Pinard puts it, forms the child out of her own flesh, not merely out of her food; the individual is being sacrificed to the species.