AUTHOR'S ABSTRACT OF THIS PAPER ISSUED 
BY THE BIBLIOGRAPHIC SERVICE, JUNE 2 
STUDIES ON THE MAMMARY GLAND 
IV. THE HISTOLOGY OF THE MAMMARY GLAND IN MALE AND FEMALE 
ALBINO RATS FROM BIRTH TO TEN WEEKS OF AGE 
J. A. MYERS 
Institute of Anatomy, University of Minnesota, Minneapolis 
NINETEEN FIGURES (ELEVEN TEXT FIGURES, TWO PLATES) 
In earlier works (Myers, ’16 and ’17b) the growth and dis- 
tribution of the milk-ducts in male and female albino rats from 
birth to ten weeks of age were studied. Owing to the fact that 
the finer structure of the gland during these ages has not been 
carefully studied and that a knowledge of such structure is 
essential before proceeding with the changes in the gland during 
pregnancy, the present work was undertaken. An abstract of 
the results has already been published (Myers, ’18). 
MATERIAL AND TECHNIQUE 
In this work. approximately forty apparently healthy rats of 
about normal weight were used. The age ranged from birth to 
ten weeks. These individuals were fairly evenly distributed 
among the described stages. For general histological work the 
glands were fixed in Zenker’s fluid, paraffin sections cut 7 or 8 u 
and stained with iron-hematoxylin or Mallory’s anilin-blue con- 
nective-tissue stain. Other glands were stained with Dominici’s 
combination stain. For the study of elastic fibers, glands were 
fixed in 10 per cent formalin and stained in Weigert’s resorsin- 
fuchsin stain or Unna’s orcein stain. Mayer’s mucicarmine was 
also applied to some glands with the hope of determining more 
accurately the nature of the contents of the intraepidermal 
portion of the primary duct. 
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