109 
Structure of the Aquatic Salamander , Sc. 
bute the confusion in which this genus of vertebral oviparous 
animals is found in our zoological systems, even those the most 
recent. Their structure has not yet been sufficiently studied ; 
the mode in which their eggs are laid and fecundated has been 
only imperfectly observed ; the development of the young ani- 
mal has not been followed with accuracy, nor through all its 
stages ; and, lastly, their species has not hitherto been deter- 
mined with precision. The object of the author in this publi- 
cation, is to till up some of these gaps, which, but for the reason 
above stated, w ould have been sooner accomplished ; for all the 
designs given in this work were made, and the notes on the na- 
tural history of the animal written, before the publication of his 
work on the proteus in 1819. 
Having thus made known the reason of the delay, the author 
proceeds now to inform the reader of the circumstances which 
determined him to undertake this branch of the inquiry. 
Whilst he was occupied in studying the organization of the sala- 
mander, and comparing it with that of the proteus, the idea 
came into his mind of following the development of the sala- 
mander from the egg up to the perfect animal. He had learned 
from the inquiries of Spallanzani, that, in these animals, fecun- 
dation w r as effected exterior to the body of the female ; and 
that, nevertheless, the action of the prolific fluid was propagated 
Within her * and Blumenbach had instructed him, that some sa- 
lamanders, which were kept in a vessel filled with water, had laid 
eggs, which were there hatched, and afforded him an opportu- 
nity of seeing and examining the gills of the young animal. To 
satisfy his curiosity on these points, the author believed that no- 
thing more was necessary than to procure females at the time of 
laying. In the month of May, therefore, he procured several 
of these reptiles, which he put into a large tub, and three days 
afterwards he found, at the bottom of the tub, about 30 eggs 
glued together endwise, three to three, and four to four, so as 
to resemble portions of a string of beads. These eggs he ga- 
thered up with the necessary care and precaution, and placed 
them in a vessel filled with a portion of the water from the tub. 
Observing them for two days, he saw them enlarge and become 
irregular on the surface, which he regarded as a prelude to the 
evolution of the germ. These appearances increased to the fifth 
