THE THYROID AND PARATHYROIDS 



267 



the external body of the cat and dog. McCarrison states that 

 there is sometimes an internal parathyroid in the rat. 



(i) In the Wolf and Badger there are four parathyroids 

 whose precise location does not call for any description. 











FIG. 67. 



FIG. 68. 



FIG. 69. 



FIG. 70. 



FIG. 71. 



FIGS. 67 to 71 are semi -diagrammatic, and show the relationship of the 

 thyroid, external parathyroids, and trachea in a series of rabbits. The 

 " internal " parathyroid is not shown, since it was found only oil micro- 

 scopical examination. 



The general arrangement conforms fairly closely with that 

 in the dog and cat. 



(j) In the Pig the internal parathyroid is stated to be 

 absent. In this animal and in Ruminants the external para- 

 thyroid is not close to the thyroid, but is in connection with 



