MUTILATIONS AND Ttf LIKE 2*7 



in the eye occurred in the offspring of animals whose eyes had 

 been operated on, injured, or infected. But experiments in which 

 the eyes are infected with tubercle or the like are not relevant 

 until all possibility of the offspring being infected is excluded ; 

 and as for cases such as those given by Brown-Sequard (1880), 

 where the extirpation of the eye-bulb in the parent was followed 

 in the offspring by the loss of one eye or of both, or by corneal 

 obscuration, it is necessary to compare the results with the statistics 

 as to the frequency of various kinds of innate eye-defects. 



Deformations. We do not know all that we should like to know 

 in regard to the artificially deformed feet of Chinese ladies, but there 

 is no evidence that the long-continued deformation has resulted 

 in any hereditary change. 



For untold ages the herdsmen in some parts of the Nile valley 

 have artificially deformed the horns of their cattle, making them 

 bend forwards, twist spirally, and so forth; but no effect on 

 offspring has ever been observed (R. Hartmann, Die Haussaugethiere 

 der Wildl'dnder. Ann. Landwirthsch. ; Berlin, 1864, P- 28). 



The Rook's Bill-feathers. Settegast and others have referred 

 to the bristle-like feathers about the nostrils and the base of the 

 bill in the young rook. They are said to disappear mechanically 

 when the bird begins to bore with its beak in the ground, yet they 

 are always present in the nestling. To cite this as an example of 

 the non-transmission of a deformation-effect is probably quite 

 erroneous, for there is no proof that the disappearance is causally 

 connected with burrowing. It is probably a constitutional pecu- 

 liarity that these feathers should be moulted and not replaced. 

 They disappear even if the rook is not allowed to bore (see 

 Oudemans and Haacke, cited by Delage, 1903, p. 223). On the 

 other hand, to start from the fact that the bristles disappear even 

 if there is no boring in the ground, and to cite this as an instance 

 of the transmission of a deformation-effect, is equally fallacious. 

 There is no evidence that it was a deformation-effect to start with. 



Some Puzzling Cases. While the argument based on the apparent 

 transmission of the results of mutilation appears to 'us very weak, 

 it must be admitted that there are some cases which, if accurately 

 recorded, are puzzling. It is desirable that any fresh cases, similar 

 in nature to those which we propose to illustrate, should be studied 

 carefully and without prejudice. Though they may not prove 

 modification-inheritance, they may lead to interesting results. 



