_a„. 



F'iff. .") A duct and its branches of a mammary gland of a rabbit in the early 

 stages oi pregnancy, prepared as described imder figure 2. The smaller blood 

 vessels are not shown; length of longest duct 15 mm. Magn. 8 diam. 



Fig. 6 Cross-section through a duct and its branches of a mammary gland of 

 a rabbit during lactation. Magn. 17 diam. 



523 



