]\Ir. F. Galton's Exjjerimeats in Pangenesis. 383 



tive results, to notice the gradually waning powers of producing 

 mongrel oflfspring. 



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 u and w experi- 

 ments had been made. 



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

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

 rabbit, just six mouths 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'' 35™, continued perfect; 12" 4 0"", perfect, but yellow to 

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

 both ways; 12" 55"", ditto; 1", ditto; 1" 5"', ditto; 1" Zj"', 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, ISrO. — Silver-grey doe, B {u), a fine large animal; her 

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

 heavier than the silver-grey. 



1", 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"' ; then 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™, perfect ; 1", silver to common perfect, 

 vice i-ersM rather poor ; 1" 2'", ditto ; 1" 7™, common to silver stopped ; 

 I disconnected and cleaned and reconnected, and by I" 1 2™ had reesta- 

 bhshed perfect cross-circulation ; at 1" 30™ I had stopped silver to 

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



27* 



