370 J. A. MYERS 



mens show a very slight increase in development over the two- 

 weeks and three-weeks stages. The ducts of the third thoracic 

 glands show a much greater development than has been observed 

 in any of the earlier stages. The ramifications are so numerous 

 that some are seen to pass superficially while others take a deep 

 course. This arrangement necessarily takes them out of the 

 plane of the main ducts. Thus from this stage the ducts become 

 so crowded that it is impossible for them all to occupy a single 

 plane, as found at birth in all except the last inguinal glands. 

 Large numbers of branches from the ducts in the third thoracic 

 gland also take a cephalic course, which is so extensive on the 

 right side that they very nearly come in contact with the ducts 

 of the second thoracic gland. On the left side the interval be- 

 tween the ducts of the two glands is greater. Figure 10 shows 

 that the abdominal and inguinal glands present much richer 

 arborizations than corresponding glands of earlier stages. Some 

 lateral buds are developed on the secondary ducts yet they are 

 not so numerous as in the first thoracic gland of the same stage. 

 The general course taken by the ducts is the same as that given 

 in previous descriptions. A well defined interval exists between 

 the ducts of the abdominal and the first inguinal glands. There 

 is also a considerable space existing between the ducts of the 

 first and second inguinal glands. However, the second inguinal 

 has sent numerous ramifications in the direction of the first in- 

 guinal gland. 



Five weeks. During the fifth week the ducts increase very 

 rapidly in length. Also a great many new branches spring from 

 the more distal ducts of the glands. The first thoracic gland is 

 much more complicated than in any of the previous stages studied. 

 Between the ducts of this and those of the second thoracic gland 

 a wide interval still exists. The interval between the ducts of 

 the second and those of the third thoracic glands has largely 

 disappeared on both sides, there being a slight overlapping of a 

 few of the ducts from each gland. In the specimens observed, 

 however, there are no anastomoses present between the ducts of 

 the two glands. 



