AtJTHOR S ABSTRACTS OF THIS PAPER IS- 

 SUED BY THE BIBLIOGRAPHIC SERVICE 



STUDIES ON THE MAMMARY GLAND 



II. THE FETAL DEVELOPMENT OF THE MAMMARY GLAND IN THE 

 FEMALE ALBINO RAT 



J. A. MYERS 



Institute of Anatomy, University of Minnesota 



TWELVE FIGURES 



Henneberg ('00) made a careful study of the development of 

 the mammary glands in the albino rat from the earliest appear- 

 ance of the glands through the conditions found in sixteen day 

 fetuses. Also the postnatal (birth to ten weeks) development 

 of these glands has been investigated (Myers, '16). Heretofore 

 the developmental conditions between sixteen day fetuses and 

 newborn rats have presented a gap in our knowledge of the 

 mammary glands. The object of the present investigation is to 

 fill up this gap, thus completing the history of the mammary 

 glands in the albino rat (Mus norvegicus albinus) to ten weeks 

 after birth. An abstract of the results has already been pub- 

 lished (Myers, 17). 



LITERATURE 



No attempt is made to review all the literature pertaining 

 to the development of the mammary gland, which is thoroughly 

 discussed in the works of Bonnet ('97), Brouha ('05), Bresslau 

 ('10) and Schil ('12). Henneberg's work ('00) in the early de- 

 velopment of the mammary glands in the albino rat is here 

 briefly reviewed, however, since the earlier stages must be 

 kept in mind to make clear their relations wdth the later foetal 

 stages described in the present paper. 



Henneberg ('00) found in an albino rat embryo of eleven 

 days, in the region of the dorsal limiting furrow (on only one 

 side), some cubical cells in a single layer representing the anlage 

 of the mammary streak. In an embryo of twelve days a mam- 



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