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under the microscope, gave the following results:—On January 
21st, an egg was removed from experiment No. 9, and another 
egg for comparison from tray No. 1.. They were photographed 
under the microscope, and it will be seen that the first was 
badly developed, whereas the second was normal in appearance. 
(1 and la, Photographs exhibited.) 
On March 18th, 1886, another examination and successful 
photographs were obtained from eggs from the same trays. 
That from experiment No. 138 was 0°24 inch in diameter, and 
had been in the peaty solution 33 days, when it was removed 
to clean water: the embryo was 0°50 inch in length, the eyes 
were very large, and more than twice the width of the inter- 
orbital space: whereas in the second specimen from tray No. 1, 
the width of the interorbital space nearly eqalled the diameter 
of the eye, and the embryo was 0°58 inch in length, while the 
two eggs were of the same size. The length of the head was 
proportionately more in the embryo which had been in the 
solution of peat than in the other, which had all along been in 
fresh water.* (2 and 2a, Photographs exhibited.) 
There exists a remarkable pathological condition among 
some fishes, both in the sea and fresh waters, being in short 
spinal disease. Several vertebrae may be consolidated into one, 
or their centras or bodies may be so affected as to shorten or 
alter the natural shape of the fish. As long ago as 1767, 
Barrington remarked upon some of these “hog-backed trout of 
Plinlimmon,” in the Philosophical Transactions of the Royal 
Society, and observed that they were only found “in a small 
basin, 8 or 9 feet deep, which the river forms after a fall 
from the rocks.” He evidently considered that the locality 
had something to do with this condition of the fish (see also 
Cambridge Quarterly Magazine, 1833, p. 391, and Cobbold, 
Edinburgh New Philosophical Journal, ii., 1855, pl. vi.) Among 
some young Salmonide hatched in Australasia from eggs sent 
* Embryos which have to contend with difficult respiration, consequent 
upon a peaty solution, appear to possess a badly developed brain and large 
eyes. Embryos suffering from frost or shocks to the nervous system also 
have an undeveloped brain but small eyes; while young parents give weak 
and often dropsical offspring. 
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