Generation of' the Lobular ia digitata. 109 



elegant forms, and the exquisite structure of all the parts. 

 When observed with a lens the ova were seen to be in con- 

 stant motion, and quite free within the bodies of the po- 

 lypi. They moved themselves backwards and forwards, and 

 frequently contracted their sides, as if irritated or capable 

 of feeling. I could observe none passing upwards between the 

 stomach and the sides of the polypi. They never assumed the 

 appearance of a string of beads inclosed in a narrow shut curved 

 tube, as represented by Spix,Jbut swam freely in the water which 

 distended the polypi, as figured by Ellis. Their motions in 

 the polypi, though circumscribed, were so incessant, that by 

 watching attentively I could observe them with the naked eye, 

 and they became more conspicuous as the ova advanced to the 

 open base of the stomach. From their restlessness, as they 

 approached that last passage which separates them from the 

 sea, they seemed to feel the impulse of a new element, which 

 they were impatient to enjoy, and by following the direction 

 of that impulse they appeared to find their way into the lower 

 open extremity of the stomach, without any organic arrange- 

 ment to lead them into that narrow canal. In their passage 

 through the stomach, which was effected very slowly, the 

 spontaneous motions of the ova were arrested, unless some im- 

 perceptible action of their ciliae, or some contractions of their 

 surface, might tend to irritate the sides of that canal, and 

 thus direct or hasten their escape. 



The clusters of ova found in autumn at the base of 

 the polypi of the Lobularia, have no relation to the ovaria 

 of higher animals. They are true gemmules or buds which 

 grow from the sides of the internal canals ; they are nourish- 

 ed by umbilical cords ; they fall off and escape when mature ; 

 and, as in other zoophytes, they leave no trace of their exist- 

 ence behind. Their spontaneous motion establishes the exist- 

 ence of this remarkable property in a tribe of zoophytes with 

 a fleshy axis, where it had not before been observed, and opens 

 to our contemplation a new and singular arrangement for 

 aiding and directing the passage of these delicate reproductive 

 globules, through the complicated bodies of animals where irri- 

 tability is nearly extinct. It would be highly interesting to 

 trace how far up in the scale of animals this simple arrange- 



