TELEGONY AND EEVEESION. 139 



will evidently be very generally adopted should telegony be 

 eventually raised to the rank of a fact.* 



If telegony is due to the direct " infection " of the germ- 

 plasm of the dam by the germ-plasm of the first or of a 

 previous sire, there seems no escape from the conclusion 

 that the subsequent progeny should resemble the first 

 oifspring rather than the previous sire. In the case of 

 Mulatto, her second foal (to the Arab horse) should, if 

 infected, resemble her first hybrid foal Romulus. I have 

 already pointed out at considerable length that Romulus 

 is surprisingly unlike his Burchell zebra sire, and I have 

 given reasons for the belief that he takes after the Somali 

 zebra, probably the most primitive of all the living striped 

 horses. Hence, if there are stripes in Mulatto's second 

 foal, it might be argued they should of necessity agree 

 with the stripes in Romulus or in the Somali zebra or in 

 some of Mulatto's ancestors. 



In other words, the result of "Infection," according to the 

 generally accepted (and it must be confessed most feasible) 

 explanation, should as far as it goes be identical with 

 " Reversion." It was in anticipation of this conclusion that 

 I was led to discuss so fully striping and reversion in the 

 Equid«, and to consider experiments with dogs at the out- 

 set of comparatively little value seeing we know so little of 

 the dog's ancestors. But if the developing ova are capable 

 of incorporating rather than assimilating germ-plasm after 

 the manner suggested by Weismann and Romanes, why is 

 telegony so extremely rare ? — according to Romanes only 

 occurring in one or two per cent, of cases; according to 

 Sir Everett Millaisnot only exceedingly rare but abnormal. 



Three reasons occur to me why telegony, if possible, 

 happens or rather appears to happen but rarely. In the 

 first place, the germ-plasm of the previous sire may only 

 be able to obtain a footing in ova at a certain stage of 

 ripeness. If germ-plasm (of the first sire) enters eggs 



* Mr. Heape evidently believes that if telegony occurs, the characteristics 

 of the first sire can only be transmitted to the offspring of the second 

 through the germ-plasm of the dam. — Nature, Dec. 30tb, 1897, p. 215. 



