444 CHARLES It. STOCKARD AND E. M. VICARI 



this is also true of figure 4 in plate 85. Figure 3 (pi. 89) is 

 from F 2 1523 $ , which was closely dachshund in body type. 

 A photograph of this dog while alive is at the right in figure 

 9, plate 30. The animal had a long muzzled dachshund head 

 and short achondroplasic legs. As we shall find beyond, the 

 pituitary of this animal is typically normal (plate 89, fig. 1). 



Figure 1 in plate 86 shows a histologic pattern that might 

 be interpreted as somewhat between those of the two parent 

 stocks. The follicles are intermediate in size and of irregular 

 outline with active cuboidal epithelium. There are smaller 

 follicles and more abundant parafollicular cells than would 

 be characteristic of the dachshund thyroid. The animal from 

 which this gland was taken, 296 9 , is shown as figure 1 in 

 plate 39 (p. 236). This figure offers a fortunate profile view 

 of the intermediate Boston terrier-dachshund head and face 

 and should be compared with the more closely dachshund 

 profile of a sister, 294 9 (fig. 2). 



The photomicrograph in figure 2 (pi. 86) shows a rather 

 mixed histologic pattern differing from both parent types. 

 There are many tiny f olicles containing only a drop of colloid, 

 and other larger ones of irregular outline with active epithe- 

 lium. This section of thyroid is from F 2 352 $ , a dog not 

 shown from life in any of the illustrations. He was a long 

 legged animal with a wide, strong head of boxer type, not 

 closely resembling either parent stock. 



Figure 4 in plate 89 is from F 2 355 9 and approaches fairly 

 closely the histologic pattern of the Boston terrier. This 

 bitch possessed the head of a poor typed Boston terrier with 

 a protruding undershot mandible. The photomicrograph of 

 the thyroid section show r s small follicles and an abundance 



PLATE 86 



EXPLANATION OF FIGURES 



Boston terrier-dachshund cross. Thyroid histological patterns in second gen- 

 eration and backcross Boston terrier hybrids. 



1 F 2 296$. 



2 F 2 352 <f. 



3 Backcross Boston terrier 524 rf. 



4 Backcross Boston terrier 525 J. 



