302 Sir Everard Home on the formation of fat 
■ ’ 
ovum in the spawn of the English frog.* The jelly of which. 
• ^’e ova are composed, I have upon a former occasion given 
an account of to the Society. The ova themselves differ from 
those of snakes and lacertas in general, in having no yelks. 
tadpole is once formed, it appears to feed upon 
the jelly, which although not absolutely albumen, is a near 
•moo vi&fii9iX9 n99c 9i9w gaol bnirl oiif .vlul 1o rb , 
approach to it. 
T ,1 * 
In this stage, each ovum is pressed into the form of an 
j . 
hexagonal prism with flattened ends, so as to form the whole 
• s liv 
one com 
mass. 
orn 
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tadpole, affe^ft leaves thWW 3 &i, r fes on each side ten 
filament Purpose of aera- 
tion of the blood ; such filaments must be considered as tem- 
te^x^|i9b n mb9J09jpiq srft !o awed/.. 
n9 ^he xa<?ji^l 9 o?^ tfiff? or eft, in its 
larva state, has the same projecting filaments, which drop off 
When the gills are formed ; they are more complex in their 
afM bnly three in number, on each side. This cir- 
j •». 
cumstance shows, that the larva of an eft is a species of tad- 
pole, and that the eft itself does not belong to the tribe of 
is a nearer approach to that of frogs. In the tad- 
as the abdomen begins to enlarge, these exter- 
^^t^we n ty^^RS\fr s ^Siilar filaments are 
met with in the foetus of the shark while contained in the egg, 
whiBfftfrS^^SSPbifo^e the a fe^^^ shell. 
The spawn of the English frog was collected on the istof 
April, 181b. On the 15th, the tadpole left the egg, but the 
filamlents or external gills were not visible, only a deep notch 
,8'g.oilv9J9iqm'O0~9moc^d oris io e-moa 0 vm ;pur 
* The tadpoles having become frogs since this Paper was read, I have been enabled 
* * 45 : s\ 
T,as 
C 9 ',?} it ii GG ; Y 
to complete the senes. 
r . :. s\ . 
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