From Francis Galton   8 April 1870

My dear Darwin

The white nose and vertical bar is, I find, of no import.¹ Bartlett² was not accessible the day I found them out but he has since told me they are common varieties & I hear the same from M^r. Royds, the rabbit fancier & judge of poultry shows,³ from whom I bought them.

Before leaving London last week, I succeeded in infusing 2 per cent of the rabbits weight in alien blood   before I had only achieved 1.25 or $\frac{1}{80}$^th part which (on the supposition of Huxley that blood constitutes $\frac{1}{10}$^th of the whole weight of the body) is only $\frac{1}{8}$^th of the blood.⁴

In other words my transfusion hitherto, has given only 1 great-grandparent of mongrel blood to the otherwise pure silver greys. and this is a very small matter.

I do not like to risk another operation on the other jugular of my rabbits till after the forthcoming 3 litters nor till after I have had some more success in the system of more abundant transfusion

I can do nothing with the blood in its natural state it coagulates so quickly, so I defribrinise it.— If I cannot ever succeed in transfusing as much into the rabbits as is necessary to make a fair experiment, I must go to larger animals & try cross circulation with big dogs.

You are very kind in giving me so much valuable advice & so much encouragement.

Miss Cobbe’s review is very characteristic. She has not however quite caught what I am driving at in religious matters & which—if the book sh^d be enough read to make it reasonable for me to do so—I shall express more clearly.⁵

Very sincerely yours | Francis Galton