2 J. IT. CUNNINGHAM. 
in this paper. A third class comprises discoveries of new facts 
concerning the processes of Teleostean development ; explana- 
tions, more or less hypothetical, of the steps by which that 
process of development has been produced by the contending 
influences of heredity and adaptation ; and attempts to draw 
from the facts ascertained concerning Teleosteans, inferences 
as to the significance of the features of development peculiar 
to other vertebrate types. To suggest such explanations, of 
some of the earlier stages of Teleostean development, and to 
draw some inferences of the kind I refer to, are the principal 
objects of my paper. 
Parr I.—PracticAL AND SPECIEGRAPHICAL. 
The facts and illustrations concerning the development of 
the herring which are contained in this paper are the result 
of a study of the development of that species made last 
year, and which has been described in a former paper (18). 
I first fertilised ova from the haddock (Gadus eglefinus, L.) 
on March 11th of the present year, off the west side of the 
May Island, on board a line-fishing boat belonging to Ans- 
truther. The eggs and milt were simply squeezed into a large 
bottle of sea-water and the eggs were not disturbed until after 
they had been taken ashore. I made observations on these 
eggs in the living condition at Anstruther, at the fish-curing 
establishment of Mr. David Murray, who very kindly placed 
at my disposal all the accommodation for my work which his 
premises afforded. The numberof eggs which I obtained on this 
occasion was small and they all died before hatching. OnMarch 
30th I obtained another supply of ova from the haddock, and also 
a number of those of the whiting, G. merlangus, L., and cod, 
G. morrhua, L., on board a steam-trawler, which was working 
a few miles to the east of the Isle of May. The eggs were 
treated in exactly the same way as the haddock eggs on the 
former occasion. I tried to obtain eggs from several other 
species of fish which came up in the trawl, but was unsuccess- 
ful, except in the case of the three species mentioned ; Lophius 
