194 



section of it was not thought advisable. In 

 this the heads were more widely separated than 

 in the preceding one, each head being sup- 

 ported by a distinct neck. The tail was also 

 double for about an inch. The most remark- 

 able deviation was found near the middle of 

 the body. In this region the size is considera- 

 bly increased, and the transverse dark bands 

 of the skin are interrupted in the middle, the 

 lateral portions remaining. On the middle 

 line passing between these is a longitudinal 

 zig-zag line, which extends the whole length 

 of the enlarged portion. In this region the 

 vertebral column is double, and provided with 

 a double set of ribs, but is single before and 

 behind it. The doubling of the vertebral 

 column in its central portion in the manner 

 above described is of very rare occurrence, 

 and does not appear to have been noticed 

 in the various works treating of monstrosity. 



Monstrosities of serpents in which the 

 head is double have been often noticed. 

 Aristotle mentions such. Redi found one 

 alive sunning himself on the banks of the 

 Arno, near Pisa, which was two palms in 

 length, and as large as the little finger. The 

 heads were of equal size, and each supported 

 by a neck of two fingers breadth in length. 

 Redi preserved it alive for several weeks, and 

 tried experiments with it ; he noticed that 

 the right head died seven hours before the 

 left. In this case the brain and spinal mar 

 row were double as far as the middle of the 

 back, beyond which the spinal cord wag 

 single. The oesophagus and stomach were 

 double, but the stomachs connected with a 

 single intestine. There were two hearts and 

 two livers, but only one set of genital or- 

 gans. 



References. — Dumeril and Bibron. Her- 

 pet. Gen. T. vi. p. 210. 

 Redi. Osservazioni intorno agli Animali Viventi. Firenze, 1684, p. 1. 

 Lacepede. (Euvres. Paris, 1840. T. ii. p. 309. 



