347 
Mr Boyes, of Beverley, writing to the Field, observed 
respecting hybrids raised between the goldfinch and the bull- 
finch, “that these mules are not so rare as that gentleman 
supposes. I have seen several such, both male and female. 
Two grand cocks were exhibited at a show of cage birds 
recently held here, and so frequently are they to be met with 
now that it requires a very high-coloured cock to win. This 
cross is, without doubt, the most handsome of all the hybrids 
between British birds, and I believe they are all produced by 
mating the cock goldfinch with the hen bullfinch. Another 
cross very difficult to procure is the one between the bullfinch 
and canary; I have only heard of one such for which the owner 
refused £10. It was sent to a show, and, through some neglect 
in supplying it with food, was hungered to death. I may 
mention that at the above-mentioned show, a hybrid between 
the greenfinch and common linnet was exhibited. This is a 
cross not often met with.” While Mr Macpherson remarked 
in the same number of the Field, “that every bird show of 
importance produces some fine pink-breasted mules between the 
goldfinch and bullfinch. I myself have examined these hybrids 
at all stages, and possessed a female which sang the song of the 
chaffinch. Hybrids between the bullfinch and linnet are less 
frequently met with, but even these are now well-known in this 
country. The really rare hybrid is that between the bullfinch 
and canary. I have only examined a single specimen of this 
hybrid, which was exhibited in London a few weeks ago, and 
was the offspring of a male canary and female bullfinch.” 
Before commencing an account of hybrids among fishes, it 
may not be out of place to refer to certain natural influences, 
some of which favour, whereas others are detrimental, to 
hybridization. Having no references to instances of crosses 
occurring among cartilaginous and cyclostomatous forms, the 
following notes will be restricted to so-called “ true fishes,” or 
Teleosteans. 
In some species of marine fishes, as the herring, Clupea 
harengus, the eggs sink and become attached to suitable sub- 
stances, consequently, unless they extruded them near the 
