244 Prof. M'Intosh's Notes from the 



The jolk had considerably diminished. At the sides of the 

 embryo were groups of minute granules, the result in all 

 probability of abnormal conditions. 



Next day- — that is, on the 7th May, the fifth day after 

 fertilization — the ova were unhealthy and the development 

 irregular. The lenses were now visible, and a prominence 

 indicated the heart. The otocysts have two otoliths. The 

 notochord is cellular, and the segmental tubes had formed. 

 Posteriorly several large vesicles were at the seat of Kupffer's, 

 and the tail seemed to be deformed. The black pigment- 

 corpuscles were stellate in front of the otocysts. 



On the 8th May one of the embryos had escajied from the 

 capsule, the latter apparently being somewhat delicate ; but 

 whether this was due to the abnormal conditions, viz. the 

 long journey and the great heat, is unknown. In this example 

 the heart pulsated and an 0])ercular aperture appeared behind 

 it. The otocysts had moved forward, the pectoral folds 

 were more distinct, and the muscle-plates more numerous. 

 The notochord was multicolumnar. Kupffer's vesicle had 

 various accessory vesicles connected with it by protoplasm. 

 The tail extended a little beyond the yolk, which had a few- 

 pale wrinkles in front, and its surface was dotted with minute 

 granules. In certain views finely branched processes pro- 

 jected from a black pigment-speck on the body to tlie surface of 

 the yolk, evidently uncoloured prolongations which afterwards 

 develop pigment. The black chroniatophores on the head 

 and along the edges of the muscle-])lates were distinct, and 

 some were slightly branched, especially on the head. In 

 lateral views the pectoral expansions were prominent. When 

 placed in pure sea-water after examination the embryo and its 

 yolk rose rapidly to the surface. On the same date an 

 embryo within the capsule was less advanced, and the heart 

 presented no movement. 



Twenty-four hours later (9th May) the extruded embryo 

 still survived, and the changes undergone in this interval 

 were as follow : — Considerable diminution of the yolk had 

 occurred, but a rupture of the sac had taken jjlace posteriorly. 

 The eyes were more clearly outlined, and pigment was develop- 

 ing in them, while the choroidal fissure was prominent. The 

 otocysts were much larger and had a rim. The heart jiulsated 

 and had endocardial papilla?. The pericardial space was large. 

 The pectoral fins siiowed a thickened rim of cjji blast. Kup- 

 ffer^s vesicle was still present. The black chromatophores 

 were more distinct, though those of the embryo in the capsule 

 were mure branched. Both sj^ecimens perished at this stage. 

 The pollack (lythe), though not uncommon, has thus been 



