Mr. F. Galton's Experiments in Pangenesis. 383 



tive results, to notice the gradually waning powers of producing 

 mongrel offspring. 



APPENDIX I. 



It is important that I should give details of the operations of 

 cross-circulation. I may mention that, having to deal with many 

 rabbits, I distinguished them permanently by tattooing bold Roman 

 numerals in the inside of their ears. 



I. Experiments of cross-circulation on one buck and two does, pure 

 silver-greys, of a breed obtained from Mr. E. Royds, of Greenhill, 

 Rochdale, the same breed as that on which all my ?< and w experi- 

 ments had been made. 



Oct. 19, 1870. — Silver-grey buck, O, out of doe A (m) hy M (m), 

 and therefore own brother to the white-footed young one, a small 

 rabbit, just six months old. His blood-mate was a 



Yellow buck, lop-eared, white throat, probably 

 one-fifth heavier than the silver-grey. I avoided unnecessary weigh- 

 ing, because it frightens the animals, and tends to interfere with the 

 final success. At 12'' 30"^ I made cross-circulation ; flow was per- 

 fect; 12'' 3.0"', continued perfect; 12'' 40'", perfect, but yellow to 

 silver-grey perhaps the stronger; 12'' 44"', ditto; 12'' 50°', perfect 

 both ways; 12" .55"', ditto; I", ditto; 1" 5"", ditto; 1" 7^"", ditto. 

 I then stopped and tied up. I tested the flow with a small and 

 delicate but very simple pulse-meter on all these occasions, not liking 

 to interfere overmuch with my fingers. I, however, used them at 

 the commencement, at 12" 50"', and at 1'' 5"'. 



Oct. 20, 1870. — Silver-grey doe, B (m), a fine large animal; her 

 blood-mate was a Common large grey lop-eared doe, about one-tenth 

 heavier than the silver-grey. 



l", cross-circulation established, apparently perfect ; I mean the 

 throbbing of the canula and artery were obvious ; 1'' 6"", felt and 

 found the flow quite good; 1'' 12"', common to silver-grey quite 

 good, vice versa poor; 1'' 15'", ditto; I disconnected and cleaned 

 and removed clots and reconnected. This I repeated several times ; 

 there was still much trouble in maintaining a proper flow from 

 silver to common grey, but common to silver was always good. The 

 operation continued till 1'' 40'" ; tben I disconnected ; and as the 

 silver-grey had received too much, I let her bleed to 4 drachms. 



Oct. 27, 1870. — Silver-grey doe, H, moderate size; her blood- 

 mate was a Common large grey doe, certainly more than a 

 tenth heavier than the silver-grey. There was some trouble with 

 her, as the carotid was abnormal, and three offshoots from it had to 

 be tied before the canula could be inserted. 



12'' 48"", cross circulation established, perfect pulse, but silver to 

 common the fullest ; 12'' 53'", |)erfect ; 1'', silver to common perfect, 

 vice versa v&ihtx poor ; 1'' 2'", ditto ; 1'' 7'", common to silver stopped ; 

 I disconnected and cleaned and reconnected, and by 1'' 12"' had reesta- 

 blished perfect cross-circulation ; at I'' 30'" I had stopped silver to 

 common and made common to silver better ; got five minutes good 



27* 



