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XVII. On the mode of generation of the lamprey and myxine . 
By Sir Everard Home, Bart. V . P. R. S. 
Read June 15, 1815. 
The observations contained in the preceding paper upon the 
organs of respiration of the lamprey and myxine, led me to 
doubt the propriety of classing these animals among fishes, 
and as their ovaria differ in many respects from those of 
fishes in general, I became desirous of knowing the struc- 
ture of the testicles in the male, to see how far they resem- 
bled those of fishes, or in how great a degree they differed 
from them. 
That the lamprey was male and female nobody seemed to 
doubt, and yet with every opportunity apparently before me, 
I was unable to procure one male. Sir Joseph Banks supplied 
me very largely with lampreys and lamperns, those that were 
full of ova were admitted to be females, and those which ap- 
peared to have no ova were said to be males ; but all of them 
had ovaria, although in some the ova were extremely small, re- 
quiring a magnifying glass to distinguish them, in others they 
had been shed, leaving the cells in which they had been con- 
tained, and the openings by which they passed out very appa- 
rent. Being accidentally at Worcester, in which city, during 
the season, lampreys are caught in the river Severn in great 
abundance, and potted to be sent all over England, I made 
mdcccxv. M m 
