EGGS OF FISHES AND THEIR DEVELOPMENT. 
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EGGS OF FISHES AND THEIE DEVELOPMENT. 
SYLLABUS OF PAPER BY J. T. CUNNINGHAM, B.A., F.R.S.E. 
(Read 26th January, 1888.) 
(1) Description of the egg of a particular species taken as 
type. Example chosen, the whiting, (a) The discharge of the 
egg or ovum from the parent fish at the annual spawning 
time, (b) The process of fertilization and the changes which 
accompany it. 
(2) The process of development in ova. (a) The formation of 
the blastodisc and the segmentation, (b) The blastoderm and 
the periblast, (c) The process of invagination and its immediate 
results, (d) The growth of the blastoderm over the yolk, with 
the consequent elongation of the embryonic rudiment, (e) The 
early development of the principal organs during the above 
process. (/) Growth of the embryo subsequent to the envelop- 
ment of the yolk; formation of the tail and the fins, (g) Hatching; 
the characters of the larva, and its gradual growth into the young 
whiting. 
(3) Comparison of the ovum of fishes with those of other 
animals, (a) The essential or primary features of the ovum. 
(b) The secondary features peculiar to particular classes. 
(4) Origin of the ovum, (a) The ovary, its essential and its 
secondary structures. (b) The ovary of fishes compared with 
those of other animals. 
(5) Comparison of the ovum of the whiting with those of 
other fishes, (a) Differences in fish-eggs in external surroundings. 
(b) Differences in internal structure, (c) Differences in the larvae 
at time of hatching. 
(6) The craft of pisciculture founded on the science of fish- 
development, (a) So-called artificial fertilization, (b) Control of 
the eggs during development. 
