THE EVIDENCE OF THE THYROID GLAND 



203 



ou each side of the operculum, and do not combine to form a 

 uterus ; I have examined them and was unable to find any glandular 

 structure at all resembling that of the thyroid gland of Ammoccetes. 

 I then turned my attention to the organs of the scorpion, in which 

 the two ducts have fused to form a single uterus. 



I there found that both in the male and in the female the genital 



Fig. 86. — Section through the Terminal Chamber or Uterus of the Male 



Scorpion. 



C, cavity of chamber. A portion of the epithelial lining of the channels of emission 

 is drawn above the section of the uterus. 



ducts on each side terminate in a common chamber or uterus, which 

 underlies the whole length of the operculum, and opens to the 

 exterior in the middle line, as shown in Fig. 76. In transverse 

 section, this uterus has the appearance shown in Fig. 86, i.e. it is 

 a large tube, evidently expansible, lined with a chitinous layer and 

 epithelial cells belonging to the chitinogenous layer, except in two 

 symmetrical places, where the uniformity of the uterine wall is 



