TRANSMISSION OF MALFORMATIONS. 187 



interesting account of the malformation of the tail in 

 these fish. The most salient peculiarity of these Loch- 

 namaorachan trout is that the rays of the caudal fin are 

 abnormally shortened, coarse at the extremities, and 

 deficient as to the amount of dichotomization and 

 number of the transverse joints ; besides which, they 

 also show a tendency to coalesce at their terminations. 

 By the convergence downwards of the upper long rays, 

 and upwards of the lower ones, the fin assumes a 

 rounded form instead of presenting the usual broad fan- 

 shaped aspect. The abnormal condition of the ex- 

 tremities of the rays may affect other fins besides the 

 caudal (fig. 98). 



The lake in question is about 1,000 feet above the 

 level of the sea. It is about an acre in extent, and so 

 shallow that a man can wade through it ; the bottom is 

 of quartz rock. Several other lochs near contain trout, 

 but none are " tailless." So constant is this abnormality 

 in trout taken from the lake in question, that one keen 

 fisher, with thirty years' experience of this loch, has never 

 taken any but docked ones. 



It is quite possible, indeed probable, that a more 

 perfect knowledge of the mode of development of the 

 spatulate or racket-shaped feathers in the motmots, 

 and of the tails in the Lochnamaorachan trout would 

 put a new complexion on the matter. It may be con- 

 fidently stated that at present there is no satisfactory 

 case known of the transmission of a defect, the result of 

 mutilation. 



Inherited Malformations. There can be no reasonable 

 doubt that defects arising in the course of development 



