1 8 ORIGIN OF A POLYDACTYLOUS RACE OF GUINEA-PIGS. 



The original polydactylous guinea-pig (J' 23, table i, p. 18), was born to 

 parents of almost unknown ancestry, but certainly not closely related to 

 each other. The mother, a spotted animal (5 51) produced no other poly- 

 dactylous offspring, though she bore in all thirty young. But the father 

 ((^41.1"), who sired in all one hundred and forty-seven young, had five 

 other polydactylous offspring. These were all, except one,* borne by females 

 descended from himself, and that one was borne by his half-sister (942.1*), 

 so that it seems certain that the polydactylous character came in every case 

 from the same individual, ^ 41.1^. A son of (^ 41.1^ — viz, 1$ 243 (table i) — 

 whose mother was half-sister to J* 41.1^, produced, like his father, a certain 

 number (five) of polydactylous offspring, which were used in building up 

 the polydactylous race. 



Table I. — Ancestry of thi various males used in building up the polydactylous race. 



The character of the extra-toe is indicated by letters following the numeral which designates each individual 

 These letters signify ; (P, good ; /', fair ; ^, poor; A', normal, i. ^., three-toed. Reid downward, 



Q'n iSf^- p4a 



ps/ 



641. 1 ^ 



g '»^. /o 



daj-f 



(5a43 



p 4a.i^.i'3 



6 NN. 



P I.A 



PI90 



6/93- 



g46i-rn P5IB-G0 S7//-0G ;?7/^-/=A' 



P 768- GO 



d635-FF 



T 



paoa-NP. 



^eaa-G/r Sao3-GG. pa/o-cG. 



d/003-ro 



paie-cG. 



1 



d 114-0 -GN. 



3ll65-GG. 



\ 

 d 954 -GO. 



pISGi-GG dl263-GG d/264-GG. 



I 



dj046-GG 



*In an earlier paper (Castle, :05) this e.xception was inadvertently overlooked, 

 and the total number of young sired by d'4i.i=' was given as 139 instead of 147. 



