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XVI Proceedings of the Association of American Anatomists 
mg 0.1% of phenylhydrazin hydrochloride and 3.27% of nitric acid 
produced no reaction with sections treated with pure molybdic acid or 
with Macallum’s nitric-molybdate reagent after three minutes’ treat- 
ment, although similar sections containing ammonium phosphomolybdate 
artificially introduced reduced to a maximum extent in the same solu- 
tion in less than one minute. Clearly, the sections treated with the nitric 
molybdate reagent contained no phosphomolybdate of ammonium. Other- 
wise the reduction would have been obtained in the presence of a high 
content of nitric acid. The experiments show that the reducing agent 
employed does not discriminate between ammonium phosphomolybdate 
formed at the expense of the phosphorus of the tissue and other molyb- 
denum compounds which are likely to be present, inasmuch as it produces 
like colored compounds with molybdic acid and ammonium molybdate. 
They show further that the phosphorus, if liberated as phosphoric acid, 
is not precipitated at the point of liberation as ammonium phosphomo- 
lybdate. Thus the essential conditions of a successful phosphorus reac- 
tion by this method are not fulfilled. 
ON THE STRUCTURE OF THE HARDERIAN GLANDS IN MAMMALS. By 
JOHN SUNDWALL. Hull Laboratory of Anatomy, University of Chicago. 
Presented by Robert R. Bensley. 
ON THE SO-CALLED TRANSITIONAL CELLS OF LEWASCHEW IN THE 
ISLETS OF LANGERHANS. By M. H. Lane. Hull Laboratory of 
Anatomy, University of Chicago. Presented by Robert R. Bensley. 
A report was made of observations on the structure of certain cells in 
the islets of Langerhans which may have been among those observed 
by Lewaschew and interpreted by him as transitional in nature between 
the islet cell and the acinus cell. Comparatively few references to these 
cells appear in the literature. Diamare described them as large deeply 
staining cells occurring on the borders of the islets of the rabbit and 
guinea-pig, and Schultze makes a similar brief reference to their occur- 
rence in the same animal. By means of Bensley’s neutral gentian tech- 
nique it has been possible to stain these cells distinctively and to deter- 
mine their characters. It has been found that they are much larger than 
the ordinary islet cells, and in preparations stained by the neutral gentian 
method, appear intensely blue, while the other cells of the islets are pale 
orange. Under high powers it is seen that the deeply stained cells owe 
their appearance to the fact that they contain innumerable minute gran- 
ules which are stained deeply with the violet component and stand out 
clearly on an orange stained background of the ordinary protoplasm of 
