ORDER BATRACHIA. 419 



we find the branches which support this apparatus grow 

 longer and longer and narrower and narrower, until they 

 finish by changing into those two long cartilaginous threads, 

 which attach the hyoid bone to the cranium, a little below 

 the fenestra ovalis. The angle which their anterior extre- 

 mity forms in front, becomes a little crotchet or hook of this 

 thread. 



At the same time the odd piece and the two rhomboidal 

 pieces become united by synostosis, extend, grow slender, 

 lose by little and little the branchial arches which were 

 attached to them, and which are re-absorbed ; and finally 

 become a large disk or buckler, the anterior angles of which 

 are widened like a hatchet, the posterior often retain in an 

 emargination which divides them, the trace of the branchial 

 arches which proceeded from them, and the posterior edge 

 has two osseous horns, which are found in the posterior angles 

 of the even pieces, and which may well correspond to the 

 lower pharyngian bones of fishes. 



The eggs of the batracians are not fecundated by the males 

 until the moment in which they are deposited by the female, 

 or in a little time after. In the deposition the male often assists 

 the female ; and then the eggs are placed in succession like 

 a chaplet, and retained either by a glutinous matter which 

 pastes and unites them into a packet, or by a substance 

 which dries up, becomes elastic, and thus retains the embry- 

 ones twisted on the thighs of the males ; or otherwise these 

 eggs are placed by the male on the back of the female, 

 whose skin swells, and forms around each of them a sort of 

 alveolus, within which the little tadpole undergoes all its 

 metamorphoses as in a matrix. Sometimes the eggs are laid 

 separately, and the male fecundates them in succession. 



At the period of generation, which usually takes place but 

 once a year, and in the spring, the males undergo a change 

 of form. Some exhibit membranous crests upon the back, 



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