1 68 HEREDITY 



the child. Under these conditions the immunity of 

 the mother of a child affected by congenital syphilis 

 and the transmission of the disease from a father who 

 to all appearance is free from the virus* are not only 

 explicable but natural events. Hereditary effects of 

 the kind just described may be compared to those 

 The in- which are due to the influence of a previous impreg- 

 a previous nation, for in both cases it is a question of the 



impregna- 

 tion, recurrence of a past state or of a past mode of 



vibration of the nervous system. In this, respect the 



following examples taken from a work by Miles are of 



very great interestt : 



' In 1815 a chestnut mare, seven-eighths Arabian, 

 belonging to the Earl of Morton, was covered by a 

 quagga (a species of zebra) ; the hybrid produce 

 resembled the sire in colour and in many peculiarities 

 of form. 



' In 1817, 1818, 1821 the same mare was covered 

 by a very fine Arabian horse, and produced suc- 

 cessively three foals, and, although she had not seen 

 the quagga since 1816, they all bore his curious and 

 unequivocal markings.'! 



' It is stated, on the authority of Mr. William 

 Goodwin, veterinary surgeon to Her Majesty, that 

 " several of the mares in that establishment " (royal 

 stud at Hampton Court) " had foals in one year which 

 were by Actaeon, but which presented exactly the 



* Osier, ' The Principles and Practice of Medicine,' p. 238. 

 t Manby Miles, ' Stock Breeding,' p. 255. 

 J ' Philosophical Transactions,' 1821, p. 20. 



