396 



The loiRNAL OF Heredity 



With rats, Bond ]3rocccdcd in the 

 following manner: an albino female was 

 first mated to an ordinary brown male, 

 and then to an albino male; with the 

 latter she produced none but albino 

 offsjjrinjj;. 



Miss Barthclet proceeded in the same 

 way with white mice: first mated with 

 a gray male, they were later mated to 

 an albino and produced only albinos, 

 with no trace of gra\-. 



THE CASE OF ALBINOS. 



I must now point out that these two 

 latter exijcriments have really no sig- 

 nificance, either for or against telegony, 

 because there is an important source of 

 error in them. If the numerous re- 

 searches into the inheritance of colora- 

 tion during recent years have shown 

 anything, it is that albinos mated with 

 each other (rats or mice) produce 

 albinos indefinitely, whatever be the 

 origin of these rats or mice. In my 

 own work I have mated white mice, 

 bom from gray ones, with white mice 

 bom from black ones, without ever 

 obtaining offspring bearing a single 

 grav or black hair. So even if we 

 should admit the impregnation of a 

 white mouse by a gray one, that im- 

 pregnation could not manifest itself as 

 the result of fecundation by a white 

 male; the results obtained in the ex- 

 periments just mentioned jjrove nothing, 

 therefore, as regards telegony. 



But rats and mice form, none the less, 

 excellent material for the study of tele- 

 gony; because even if, mated with each 

 other, albinos produce onl\' albinos, the 

 identity of coloration does not conceal 

 irrii)ortant constitutional differences, as 

 I haVe already pointed out. These 

 differences appear if a wild gray mouse, 

 for example, is mated with an albino 

 bom of a striped black or striped gray; 

 black or striped offspring will necessarily 

 a])pear in the second endogamous gener- 

 ation, thus Ix-aring witness to the in- 

 fluence of the ancestry of the albino. 



Reasoning from these exijerienccK, I 

 mated white mice having neither black 

 nor stripes in their ancestry, and wild 

 gray mice, with a strii)ed black male. 

 The members of the first filial generation 



were all uniformly gray, and all alike, 

 as usually hapyjcns. Mated with each 

 other these mice in their turn furnished 

 gray, black and strijxd mice, thus 

 pro\-ing that the general constitution of 

 the first filial generation can, in certain 

 conditions, show itself by the black 

 coloring or stri]jing. In consequence, 

 if the impregnation of the mother really 

 took place, she ought to be able to 

 reveal it by transmitting black colora- 

 tion or striping. 



EXPERIMENTS WITH MICE. 



To i^rovoke its appearance, I sub- 

 stituted for the striped mouse a wild 

 gray mouse in whose ancestry there was 

 not, to my certain knowledge, any in- 

 dividual either black or striped; the 

 appearance of such individuals in the 

 posterity of these females, i)re\-iously 

 mated to the striped male, would then 

 have been a very strong ])resumption 

 in favor of telegony. None aiJ])eared. 

 All the litters obtained, with one excep- 

 tion, contained nothing but gray mice, 

 quite uniform in appearance. 



I have noted one exception: it is in- 

 teresting from several viewpoints, and 

 particularly from that of telegony. 

 One litter contained three wild-gray 

 mice and two light gray ones with a 

 brownish tint. If this tint had been 

 darker, I should have been led to admit 

 the possible of a telegonie impregnation ; 

 if it had been lighter, such an interpre- 

 tation could not have been supi^orted. 

 for it amounted to no more than a 

 difference in color among the different 

 mice. In many cases, nothing more 

 than this has been necessary to "j^rove" 

 the influence of a previous sire. Here, 

 however, the difl'erencc of tint offers no 

 such explanation. Ijccause other wild 

 albino couples, the female of which had 

 never been mated with a stri]X'd male, 

 furnished me with absolutely analogous 

 results. Nothing remained l)ut to 

 await the result e)f malings between the 

 differe^nt individuals of this Fj genera- 

 lion; none of ihe matings thus made 

 resulte'd in any trace of a l)laek n.ouse or 

 a stri])ed one. 



1 made anolhe-r experiment along 

 slightly different lines, starting with the 



