PI PA. 169 



this extraordinary animal were produced in the 

 dorsal cells, without having been first excluded 

 in the form of spawn ; but later observations have 

 proved that a still more extraordinary process 

 takes place ; and that the spawn after exclusion, 

 is received into the open cells of the back, and 

 there concealed till the young have arrived at 

 maturity. This discovery was made by Dr. Fer- 

 min, who had an opportunity, during his resid- 

 ence at Surinam, to investigate the natural his- 

 tory of the Pipa in a more accurate manner than 

 had before been practicable. His account is, that 

 the female Pipa deposits her eggs or spawn at the 

 brinks of some stagnant water; and that the male 

 collects or amasses the heap of ova, and deposits 

 them with great care on the back of the female, 

 where, after impregnation, they are pressed into 

 the cellules, which are at that period open for their 

 reception, and afterwards close over them ; thus 

 retaining them till the period of their second 

 birth ; which happens in somewhat less than three 

 months, when they emerge from the back of the 

 parent in their complete state. During the time 

 of the j" concealment, however, they undergo the 

 usual change of the rest of this genus, being first 

 hatched from the egg in the form of a tadpole ; 

 and gradually acquire their complete shape, some 

 time before their exclusion. This latter circum- 

 stance, which does not appear to have been 

 known to Fermin, is confirmed by the united tes- 

 timonies of Camper, Blumenbach, and Spallan- 

 zani, who have all had an opportunity of inspect- 



