68 THOUGHTS ON ANIMALCULES. 



In several individuals one or two enlarged ova were 

 perceived, and these were situated on the side of the 

 body, (pi. X, e, e). The first perceptible change was the 

 gradual appearance of a dark nucleus in the largest 

 ^&o' (pi. X, fig. 1, e\ which increased till it occupied 

 the whole of the cavity, except a narrow pellucid 

 border, (pi. xi, fig. 4, /). A slow semi-rotatory mo- 

 tion now became manifest in the inclosed embryo, 

 which in a few hours assumed a definite shape, appear- 

 ing like a soft, elongated, coiled up body, the head 

 being bent over the other extremity, (pi. xi, fig. 4, g). 

 The movements of the embryo soon became more 

 frequent and powerful, till at length the ^gg burst, and 

 the young animalcule escaped into the cavity of the 

 sheath, (pi. x, fig. 2, K), In this stage it was of an 

 elongated conical figure, having the largest extremity 

 fringed with cilia, and might readily have been mis- 

 taken for a Stentor, or similar polygastrian. The 

 young one, in the instance described, made its way to 

 the bottom of the sheath, from which, at the expiration 

 of three hours after its liberation from the ^gg^ it 

 escaped, and swam freely in the surrounding water*. 



* In another individual, according to the observation of Mr. Lee, 

 the young one (from the uppermost egg, pi. x, fig. 1, c) escaped 

 from the upper extremity of the sheath, near the base of the rotatory 

 organ. 



