26 E. V. COWDRY 
position by all investigators (Negri, ’00; v. Bergen, ’04, p. 533; 
Bensley, ’11, p. 364; Kolster, 713; Cajal, 714, p. 169, and others). 
The same generalization also holds for the salivary glands and, 
to the best of my knowledge, for all glands in which the secretion 
invariably passes in the same direction, at any rate under normal 
conditions. 
By means of a new method, Bensley (16, p. 48) has shown 
that the thyroid is peculiar in another respect by confirming the 
suspicion, which physiologists have for some time entertained, 
that the secretion may change its direction and pass immediately 
into the peripheral blood vessels without first being stored in 
the follicular cavity. The technique consists of staining with 
Brasilin in phosphotungstic acid after formalin-Zenker fixation 
and of counterstaining with wasserblau in phosphomolybdic 
acid. ‘This brings to light the true secretion antecedents in the 
form of tiny vacuoles which contain a dilute solution similar in 
its properties to the colloid of the follicular lumen, but less con- 
centrated. Since the droplets always occur in the outer poles 
of the cells, he concludes that the secretion ‘‘is destined to direct 
transport into the vascular channels, and that the thyroid cell 
presents a true reversal of polarity in accord with its endocrine 
function.”’ He believes that only when ‘‘the rate of secretion is 
in excess of body needs, the indirect mode of secretion comes in, 
and the product of secretion is condensed and stored in the intra- 
follicular cavity.”’ By way of further evidence, he calls to mind 
the fact that in exocrine glands fat droplets ‘‘ practically always 
make their appearance in the anti-secretory pole of the cell.” 
In the thyroid they are confined to the end of the cell next to the 
lumen, which would indicate that the secretion is discharged from 
the opposite pole, remote from the lumen, in accordance with 
his hypothesis. Still other evidence may be cited. 
Norris’s (18, p. 462) suggestion that Bensley’s hypothesis of a 
reversal is unnecessary because the interfollicular spaces may 
represent the primitive lumina, so that the secretion has always 
passed in this direction, is not substantiated. The presence of 
the reticular material in so many cells between the nucleus and 
the follicular lumen, as I have described it in the guinea-pig or 
