RELATIONS OF KIDNEYS IN HALIOTIS TUBERCTTLATA. /9 



cardial opening stray ova might even make their way through 

 it. It therefore seemed to me advisable to examine specimens 

 of Haliotis taken during the breeding season, 



Haliotis tuberculata may be obtained in fair numbers 

 round the coasts of the Channel Islands, more especially on 

 the rock-strewn shores of Guernsey and Sark, where it passes 

 its sluggish life attached to the under-side of large boulders. 

 It therefore lives with ventral surface uppermost, and is said 

 by the fishermen often to die if removed from its attachment 

 and left in the reverse position. It frequents the upper part 

 of the Laminarian zone, and seems to feed largely on small 

 algae. The breeding season in this locality I have found to 

 extend from about the end of December to the middle 

 of February, and the specimens used for this investigation 

 were collected in Guernsey during the spring tides of that 

 period. They were soaked in 5 per cent, formalin, and 

 mostly examined within a few days of their capture. The 

 specimens were carefully taken out of their shells, and before 

 they were placed in water or dissected at all their pericardia 

 were opened on the left side well away from the kidney wall. 

 The contents of the pericardial fluid wei-e then examined, 

 and found to consist mostly of corpuscles, a few epithelial 

 cells, and sundries. One specimen, however, yielded a 

 pinkish fluid, in which floated several ova; while two or three 

 others also yielded each a few ova in the same way. The 

 ova are very different in appearance from the other peri- 

 cardial contents, and from the components of the various 

 tissues abutting on the pericardium. They seem to retain 

 their ovarian covering and a short stalk for a considerable 

 time, very few having been found without them. The 

 nucleus is prominent, and there is a small granular accumula- 

 tion usually near the short stalk (see fig. 4, h). 



An interesting feature in the female at the breeding time 

 is a characteristic pink coloration more or less diffused over 

 the whole body, but most noticeable on the covering of the 

 hepatic ctecum, on the pericardial wall, on the head above 

 the tentacles, and on the floor of the mantle cavity. 



