MONSTROSITIES 315 



be founded on a monstrosity appearing suddenly, and in another 

 place he rejects this idea.^ 



M. Guinard finds that he cannot make any distinction between 

 a variation and an anomaly, and I find myself unable to make 

 any distinction between variation, anomaly, and monstrosity. They 

 are only degrees of the results initiated congenitally during 

 embryonic development, under different conditions of physical 

 surrounding. The latter may give rise to a new type suddenly, 

 provided it is viable and reproducible ; the former may give rise to 

 a new type by gradual accumulation of a variation in a certain 

 direction. It seems to me that we must have them b&th as 

 factors in the origin of species. 



Dr. Wallace's own observations of certain facts in nature can only 

 be explained by initiation as monstrosities, and not by gradual 

 accumulation of minute variations under adaptive conditions. In 

 his Travels on the Amazon, p. 58, he says : ' What birds can have 

 their bills more peculiarly formed than the Ibis, the Spoonbill, and 

 the Heron ? Yet they may be seen, side by side, picking up the 

 same food from the shallow water on the beach ; and on opening 

 their stomachs we find the same little Crustacea and shell-fish in them. 

 So of the fruit-eating Pigeons, Parrots, Toucans, and Chatterers.' 



It has been assumed by some writers on Natural History that 

 every wild fruit is the food of some bird or animal, and that the 

 various forms and structure of their mouths may be necessitated by 

 the peculiar character of the fruits they are to feed on ; but there 

 is more of imagination than fact in this statement ; the number of 

 wild fruits furnishing food for birds is very limited, and birds of the 

 most varied structure, and of every size, will be found visiting the 

 same tree. 



Is not all this clear evidence that it is not always the habit of 

 ^ See Fortnightly Review for May 1893, P- 657- 



