60 



BULLETIN 34, UNITED STATES NATIONAL MUSEUM. 



was inclosed. At this time it is about half an inch in length, and con- 

 sists simply of head, body and tail, the latter with a well-developed fin, 

 extending from the head and anus to the extremity of the body. Ees- 

 piration is performed by means of three gills projecting from each side 

 of the neck, of very simi)le construction, however, and with but few 

 branches. The absence of limbs is compensated by the existence of a 

 club shaped appendage on each side of the head, proceeding from the 

 angle of the mouth, and representing the cirri observed in some adult 

 salamanders. By means of these appendages the young salamanders 

 are enabled to anchor themselves securely to objects in the water. In 

 the course of a few days a tubercle is seen to form on each side, just 

 behind the head and under the gills, which elongates, and finally forks 

 at each end, first into two, then three, and at last into four branches, 

 thus exhibiting the anterior extremities, with the four fingers, which 

 latter, in the larva, are very long. Before the fore-legs become com- 

 pletely formed those behind sprout out in a similar manner, with first 

 three, then four, and finally five toes. During this time the gills have 

 increased in the number of branches, and finally exhibit a beautiful 

 arborescent appearance, in which the circulation of the blood can be 

 distinctly seen by means of a simple lens. (See plate 16.) 



5 "7 



Fig. 'i.—Amblystoma pivnctatum.. Hampton, Va. 



k 



