REPRODUCIBLE PARTS IN REPTILES. 5G7 



I 



the young larvae of Rana temporaria and Bombinator igneus, Dr. 

 Giinther cut off the tail, and it was reproduced before the time 

 when its absorption normally commences : it was transparent and 

 colourless, a small quantity of pigment being deposited at its root 

 only. i Larva? from fourteen to twenty days old did not survive 

 the loss of the entire tail, probably because they are disabled from 

 obtaining the requisite food ; but if only a portion of the tail be 

 cut off, it is more or less completely reproduced until its growth 

 is arrested by the commencement of the last stage of metamor- 

 phosis. If a hind limb be cut off when the larva is about two 

 lines long it is reproduced. No part of an Anourous Batrachian 

 is reproducible after completion of the metamorphosis, not even 

 the interdigital Aveb.' 1 



In Reptilia the power of local reproduction has been exemplified 

 chiefly in respect of the tails of Lizards. Hunter's preparations, 

 nos. 2208 2223, are all from this order, and include species of 

 Ameiva, Gecko, and true Lacerta. No instance of the restored 

 tail shows ossified vertebras, and some exemplify the tendency to 

 greater abnormality in the reproduced part. A structure of the 

 normal caudal vertebra?, related apparently to this property, is 

 noticed at p. 59 : the caudal muscles, by their proportions and 

 interlocking arrangement, seem likewise to favour the rupture of 

 the tail. When it is cast off, it continues to writhe for some 

 time, and, when these motions have ceased, exemplifies the reflex 

 function on being pricked or otherwise irritated. 



The degree in which the reproduction of parts is exemplified 

 in Fishes awaits the results of experiments. Van der Hoeven 2 

 affirms that parts of the fins are restored after amputation, and 

 that the power is limited to this extent. Amputation of the 

 small adipose dorsal fin has, however, served to mark an individual 

 Salmon from its e parr ' state to that of the f grilse ; ' 3 and it appears 

 that only the peripheral (dermoneural or dermohsemal) rays are 

 reproducible, and to this the hard ones in Acanthopterans form 

 an exception. * The modified dermoneurals forming the cephalic 

 tentacles of Lophius and Antennarius are as frequently repro- 

 duced as they are injured, to meet the particular use which these 

 angling fishes make of them:. they may be observed in every 

 stage of growth. Lost parts of fins appear to be more easily 

 reproduced in young than in old fishes.' 4 



1 MS. Notes by Dr. A. Giinther. " cccv. vol. ii. p. 52. 



3 cccxxxiv. ' The wound caused by marking was covered with skin, and in some 

 a coating of scales had formed part.' Page 5. 4 MS Notes by Dr. A. Giinther. 



