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Part III. — Twenty -fifth Annual Report 



they were massed together or separate — probably glandular. The veins 

 were of a dark amber colour. 



The female mussel had a mantle of an uniform light-pink colour 

 Although it is fuller than in the mussels examined in June, it is not 

 completely filled. It was about gth of an inch in thickness. On cutting 

 into the mantle a pink or red-ochre fluid was obtained. It consisted of 

 eggs (most of which were partially or wholly emptied of their yolk 

 contents), reddish yolk corpuscles, and nuclei. All the eggs had a distinct 

 pore in the zona ; it varied in size, and had ragged edges in some cases as 

 if it had been torn away from some attachment (fig 12). The nuelei are 

 very ductile, as they pass out through an opening smaller than their own 

 diameter. They have a sharp outline, with a distinct hyaline outside 

 layer ; the contents are granular, and enclose sometimes a nucleolus. 

 In no case did the nucleus show a ruptured or crumpled 

 wall. In some cases the nucleus (n) plugs the pore (fig 35). 

 The eggs are arranged in a pouch which seems to be an 

 expansion of a large vessel. The egg would appear to be attached by its 

 outer layer to the inside wall of the pouch. When the egg is torn from 

 its attachment the yolk granules usually pour out, although it is not so 

 in every case ; vide fig. 12, where the inner layer of the zona is evidently 

 preventing the escape of the yolk. The inner layer appears to be very 

 delicate. The outside of the pouch was also supplied with what looked 

 like vessels. The mantle tissue on teazing is reduced to eggs and a 

 stringy material, probably vessels. There is no evident amount of fat. 

 In the abdominal process were found eggs, and some round cells with 

 granular contents and others with brown granules. The round cells are 

 in total size only about equal to the nucleus of the egg. Under a 

 high power the yolk granules are amber-coloured. 



These mussels were judged to be of good quality from the fishing point 

 of view. By one authority they were referred to as " fatty mussels " (figs. 

 93 and 95). 



Another of these mussels had a mantle which in general colour 

 resembled a peach. It had a cream-coloured ground, with an amber 

 mottling. The eggs were amber in colour. 



Sept. 2, 1907. — The mussels supplied at this date by the merchant 

 were, in respect to the mantle, coloured white in some cases, cream in 

 others, and in a proportion orange-cream. 



The white mantle had a slight cream tinge. It was not thick, only 

 ^g-inch. Under the lens it showed a close white network with translucent 

 amber-coloured spaces between. Owing to the great development of the 

 white branching in the inferior half of the mantle, the translucent parts 

 are merely dots there. In the superior portion, that next its attach- 

 ment to the organ of Bojanus, the branching is less close and the spaces 

 bigger. The white branching extends over the organ of Bojanus in close 

 connection with the surface vessels : it is along each side of the vessels 

 and their branches. The vessels in the mantle are translucent, and their 

 branching forms a translucent network. There are a few small patches 

 of amber-coloured corpuscles on the superior part of the mantle, near the 

 posterior adductor. On teazing a portion of the mantle, nothing was 

 made out except a mass of minute corpuscles bound with connective 

 tissue, and a few groups of amber-coloured bodies. In a portion from 

 the superior part of the mantle there was, in addition to the above, some 

 transparent bodies, certain of which showed part granular contents and 

 more or less irregular outline. 



Up till November 2, mussels containing ripe sperms and full-sized eggs 

 were obtained. On this date the ovaries could still be made out on the 



