﻿Dec, 1857.] 



ELLIOTT SOCIETY. 



263 



searching my jars for Bolina embryos, I encountered some very 

 minute fragments of this sort, which, from a combination of favor- 

 able circumstances, underwent a portion of their changes under 

 my observation. Among the smallest and least developed of 

 these, was the specimen figured PI. 14, fig. 8. It was at first little 

 larger than the largest ova seen in the tubes of Bolina, and of an 

 avoidal or irregularly spherical form. On one side was a portion 

 a of the parenchyma of the original animal, which bore two par- 

 allel rows of cilia, four in each, c. These cilia appeared to be as 

 long as those of the smallest embryos described above. 



The opposite s.ide t, and the mass of the organism, were at first 

 perfectly transparent, but soon began to assume a granular ap- 

 pearance. This side t began to assume a somewhat conical form. 

 Next on each side of this cone indistinct points and projections 

 appeared, four or five on each side.* Under this form the animal 

 revolves very freely, stopping now and then for a few moments, as 

 if to rest. Soon the conical sides began to be separated from the 

 ciliated side by a constriction, w T hich gave it a bi-lobular appear- 

 ance. The points and projections t have shortly after this been 

 replaced by two more or less long tentacula, and the organism has 

 the form represented in fig. 13. These tentacula were extremely 

 like those of the embryos of Bolina, and were composed throughout 

 their length of nodes which may have represented contracted lateral 

 threads. The organism swam freely, extending or contracting its 

 tentacula at will, sometimes carrying one of them extended, and 

 the other contracted. After this the size increased, but so great 

 was the transparency of the organism, and the difficulty of defin- 

 ing its outlines, that great doubt remained on my mind of the 

 accuracy of the following details. Apparently, that portion which 

 supported the tentacula (fig. 13, e,) became greatly enlarged, and 

 began to protrude beyond them as in fig. 14, e, thus causing the 

 tentacula to appear relatively closer to the constriction which first 

 appeared, separating them from the ciliated lobe of the embryo. 

 Next this lobe e, fig. 14, enlarged and appeared to become divided 

 into two other lobes, (rf and e, fig. 10,) by a constriction p, in which 

 appeared to be situated the tentacula. And these tentacula now 

 appeared to be composed of two threads instead of one, as at first. 

 The lobe d, next appeared to be divided into two lesser lobes by a 

 constriction, whose plane was at right angels to the plane of the 



♦Compare this with Will's figure PI. 1st, fig. 7. 



