chap, in.] vertebrae: recapitulation. 127 



vertebra presents a transverse process on the right side which is bifur- 

 cated at its extremity. 



The remaining vertebra, though slightly asymmetrical, present no 

 special peculiarity, except that the neural arch of the ninth vertebra is 

 feebly developed. Bourne, A. G., Quart. Jonrn. Micr. Sci., 1884, xxiv., 

 p. 86, Plate. 



There is here backward Homoeosis of the atlas, the only case 

 of the kind I have met with 1 . The reduplication of the transverse 

 processes of the third vertebra should be studied in connexion with 

 the cases of double vertebrae in Python (No. 7) and the cases of 

 bifid rib (in Man, No. 12), for they present a variation perhaps inter- 

 mediate between these two phenomena. 



Bombinator igneus. In this form there is a considerable range 

 of variation in the development of the transverse processes for the 

 attachment of the pelvic girdle. 

 59. Gotte figures a specimen in which the flat expanded transverse 

 processes have a similar extent on the two sides, but while that on 

 the right side is made up of the processes of the 9th and 10th vertebne 

 (in about the proportions of two to one), that on the left side is 

 entirely formed by the transverse process of the 10th vertebra. Gotte, 

 Entiv. d. Unke, Atlas, PI. xix., fig. 346. 

 *60. Sardinian specimen figured in which the processes for the attach- 

 ment of the pelvic girdle seem to be composed entirely by those 

 of the 10th vertebra while those of the 9th are not developed. Gene, J., 

 Mem. Reale Ac. cli Torino, S. 2, i., PI. v., fig. 4. 



61. Specimen figured in which both transverse processes of 9th and 

 of the 10th are almost equally developed to carry the pelvic girdle. 

 Camerano, L., Atti R.Ac. Sci. Torino, 1880, xv.,fg. 3. 



62. Specimen in which the left transverse process of the 9th bears 

 the pelvic girdle on the left side, and the right transverse process 

 of the 10th bears it on the right side, while the corresponding processes 

 of the opposite sides were not developed. Similar case recorded in 

 Alytes obstetricans by Lataste, Rev. int. des Sci., m., p. 49, 1879 

 [not seen, W.B.] ; ibid. Jig. 4. 



63. Specimen in which the transverse processes of the 9th alone 

 were developed to carry pelvic girdle, but the proximal end of the 

 urostyle was laterally expanded more than usual, ibid. p. 7, Jig. 3. 



[Case of hypertrophy of coccyx, ibid. Jig. 6; ad hoc v. Bedriaga. 

 Zool. Anz., 1879, il, p. 664; Camerano, Atti R. Ac. Sci. Torino, xv„ 

 p. 8.] 



Recapitulation of important features of Variation as seen in the 

 vertebral column. 



I. As regards fact. 



1. The magnitude of the variations. 



2. The rarity of imperfect vertebne. 



3. The phenomenon of imperfect Division of vertebras and 



ribs. 



Adolphi, I. c, p. 352, PI. xn. fig. 3 gives an account of a specimen of Bufo 

 variabilis in which the atlas bore a transverse process on the left side only. In 

 this specimen the first two vertebrae were united and their total length was reduced. 



