CAUDAL ABNORMALITY IN LIZARDS. 687 



area that the tail-like growth arises. The assumption of caudal 

 scaling at a place so far removed from the tail by a growth so tail-like 

 in form is very noteworthy. Its internal structure has not been 

 examined, but it may perhaps resemble that of the two dwarf supernum- 

 erary tails of an Anolis graharni. Gray (Iguanidce), from Jamaica 

 which are illustrated in fig. 9„ From the cloaca the main tail is 2*5 cm. 

 in length, and at 1*8 cm. from the former there is a swelling 

 which serial sections show to be the starting point of a reproduced 

 extremity. From this swelling two short curled branches arise later- 

 ally, each being '3 cm. long, while the main axis of the reo-rowth 

 attains a length of "8 cm. beyond them. Internally the main axis has 

 all the usual characters of a reproduced tail, but the two branches are 

 merely free lateral prolongations of muscle bundles covered by skin 

 and small scales. They do not contain any endo-skeleton, and the 

 cartilage tube of the main axis shows no signs of sending branches 

 into them. As the latter become free they leave the cartilage tube 

 surrounded only by fascia, in which are scattered here and there some 

 small muscles. Towards the extremity of the main tail these muscles 

 gradually increase, and finally ensheath the cartilage tube in the usual 

 manner. This case presents obvious differences of structure from 

 those previously described. 



In conclusion, the main features of the several abnormal conditions 

 of reproduced tails described above and in my previous paper may 

 by summarised. 



(a) Condition bifid. — Main axis formed by the normal tail. A 



branch having the structure of a reproduced tail arises from 

 a possibly injured place on the main axis. 



(i) The forking is in the vertical plane. Lacerta agilis. 

 (Probably the case in the same species quoted from Giebel 

 should be placed here.) 



(ii) The forking is (nearly) in the horizontal plane. 

 ? Trogonopliis wiegmanni* 



(b) Condition bifid. — A structure entirely of the nature of a repro- 



duced tail, and completely bifid from its commencement arises 

 from the extremity of a broken normal tail The scaling 

 indicates that one of the branches has greater claim to be 



* Jour. Bombay Nat. Hist. Soc, loc. cit., p. 32. 



