HIRUDO. 47 



About the 20th of May, a faint, dull, whitish patch appeared on the 

 under surface of a specimen which had been taken in the course of spring. 

 It seemed as if sunk in the flesh, and of indefinite form. But in a week 

 it was so far advanced as to exhibit about forty ova, rather irregularly 

 disposed. When viewed from below, they were much more distinct, and 

 in two days appeared globular, and of a fine yellow. 



Another prolific specimen was taken on June 5. Being committed 

 to a glass vessel it adhered to the bottom, and continued to do so while 

 the vessel was reversed. Now, a large portion of the belly was discover- 

 ed to be invested by a stratum of eighty-three spherical ova, like beautiful 

 minute pearls. They were arranged in six rows with tolerable regularity : 

 but I could not determine whether they were contained in a pouch, or 

 simply adhered to the belly of the parent. Fig. 9. Next morning it had 

 shifted its position. Twenty-seven of the ova having been detached, 

 they lay at the bottom of the vessel. 



More continued to separate, so that on the 19th, only three remain- 

 ed attached to the body of the parent. Many had also decayed. 



Those in preservation were of a fine vivid yellow colour. But they 

 were resolving into a different form, and becoming more plump and 

 yellow, but not extending over above a line in length. 



On the 21st a group of ova was delineated, the individuals appa- 

 rently contained in a transparent segment. Unluckily they did not 

 reach farther maturity ; nor were any of them divested of the involu- 

 crum. Fig. 11. 



On the same day, the 21st, the parent was entirely free of ova. 



I regretted the loss of the young, from the difficulty of finding spe- 

 cimens to complete my course of observations. 



However, another specimen exhibited brood on July 11, amounting, 

 as I conjectured, to seventy or eighty spherical and ovoidal yellow ova 

 or capsules. It may be here remarked, that the natui'al evolution of 

 spherical ova with a flexible integument, is necessarily into an ovoidal 

 form, as mere prolongation of two opposite parts must have this result. 



This new specimen was rather under size, for there is a great and 



