1884. | Zoölogy. 1159 
of species existing in Great Britain had been unduly multiplied 
by local races or varieties which were considered as species. Dr. 
Day first describes a hybrid between Salmo salar and S. levenen- 
sis, the Loch Leven trout. Here it may be said that he has 
raised several parrs “ with comparatively large ova, which were of 
a deep reddish color, thus almost disposing of the statement that 
‘no parr has ever been found with mature ova’ | Gunther's Intro- 
duction to the study of Fish, p. 639]. Certainly the ova were 
not mature, but would have been had the fish not met with an 
untimely end while the parr-marks were present, and so likewise 
were the silvery scales of the smolt. And as I shall show, we 
found at the end of November other females with ova, in all of 
which the parr-marks were visible.’ 
His observations also “ conclusively show that the females, 
without descending to the sea, may develop eggs in fresh water. 
And though we know that in the case of rivers in which their 
access to the sea has been cut off, or their migrating to the ocean 
prevented from any cause, these fish have usually disappeared 
from such streams, still we are aware that land-locked salmon are 
found in various parts of the globe.” ; 
ooo ova were taken from an American 
charr (Salmo fontinalis) which were fertilized with milt from a 
Leven trout; many of the young were more or less and 
rom 
Leven trout-milt, The same reason which appears to militate 
against trout-eggs being impregnated by salmon-milt probably 1s 
he cause, z. e., the size of the spermatozoa. Thus the compara- 
tively large Loch Leven trout-eggs were fertilized from the milt 
of the charr; but when the converse was tried the success was 
much less, As the American charr-eggs are much smaller than 
ose of the Loch Leven trout, it is reasonable to suppose “a 
Spermatozoa are also smaller, and consequently were readily a 
arty but when it was attempted to seh sg" the ee a 
’ the milt of S. /evenensis probably the large Spe 
did not readily find entrance, thus accounting for the great pro- 
Portion of unhatched ova. * * * * kether 
we possess several or only one species of river trout. The fore- 
Soing descriptions of hybrids show that although prt the sal 
icted to the brook trout), 
i : investigations at Howietown have likewise s 
mode of color may occur in o 
Males,” y 
