Will you tell Mr Linton,3 that I am sorry to have troubled him with so many messages; but I had always thought that canaries & goldfinches, when paired, produced fewer young-birds than the pure parents; & I was particularly curious to know the cause of this.— I am sure that fewness of young is generally the rule, as in common mule from Horse & ass,—& from pheasant & Fowl.— But I shall be very much obliged for any facts about the eggs either of hybrids or of first crosses.—4
Please cite as “DCP-LETT-2029,” in Ɛpsilon: The Charles Darwin Collection accessed on