Gatty Marine Laboratory^ St. Andrews. 179 



bristles is apparent. In many an opaque, dull whitish con- 

 dition occurs in the anterior feet, which are filled with the 

 large granular perivisceral corpuscles. Moreover, almost all 

 have a touch of white at the base of the dorsal cirrus — from 

 one end of the body to the other, a similar touch occurring 

 at the tip of the ceratophore of each tentacular cirrus. 



Mendthal* figures tw^o examples, one of tiie general 

 brownish-orange hue of the ordinary type, and the otlier of 

 this colour in the anterior fourth, whilst the rest is of a grass- 

 green tint. He considers that the latter (green) colour is 

 due to a diet of green algge, a condition which is not in 

 accordance with tlie observations at St. Andrews, where the 

 greenish hue appeared to be the result of the presence of 

 masses of more or less ripe ova. There is no reason, how- 

 ever, why a. diet of Ulva or other green alga should not tint 

 the digestive canal green. 



In the male the sperm-cells (PI, VITI. fig. 2) filled the 

 various cavities even to the bases of the dorsal cirri throuo-h- 

 out January, but though the body-wall was frequentl)^ 

 distended, no degeneration of the muscular bands could be 

 observed. In tlie females the size and abundance of the 

 ova in particular examples varied, but, as a rule, the granular 

 ova with a slightly stained nucleus and a more deeply stained 

 nucleolus were more or less advanced towards maturity. 

 Occasionally an example with few and small ova appeared. 

 In some of these the muscular walls of the body were con- 

 tracted, and very few ova, and these of small size, occurred 

 in the perivisceral space. More frequently they were found 

 in the feet. Masses of ovigerous tissue were attached to the 

 vessels near the bases of the latter ; and cellular masses (it 

 may be parts of the dorsal organ) with boldly stained nuclei 

 passed upward at the bases of the feet within, as well as 

 without, the lateral lobe of the dorsal longitudinal muscles, 

 and similar cells passed into all the spaces of the feet — in 

 specimens having a considerable number of large ova. These 

 loose ccelomic masses probably represented the cells alluded 

 to in the living forms. 



In February the increase in size and the division of the 

 sperm-cells formed the most noteworthy feature, but no free 

 sperms were seen. In the other sex the ova in many had 

 considerably increased in size, and from the ajipearance 

 of the annelids a large number of ova must have been 

 discharged. 



* Untersuch. u. d. Mollusken ii. Anneliden des frischen Ilafls, p. 0, 

 Taf. figs. 1 & -2 (Konigsberg, 1889j. 



